JPH06158747A - Sound insulating device - Google Patents

Abstract

PURPOSE:To eliminate intensified exciting of specific vibration mode on a panel surface and to greatly enhance sound insulating properties over a wide range of frequencies. CONSTITUTION:A sound insulating panel which has a space 3 closed by panel materials 1a and 1b that are facing each other and surrounding material 2, a speaker 4 which emits sound wave within the space 3, a driving part 5 which drives the speaker 4, a noise detecting sensor 7 which detects noises which come from a noise source 6 and a vibration detecting sensor 8 which detects vibrations of the panel material 1b are provided. By controlling the power to drive the speaker 4, based on the signals from the noise detecting sensor 7 and the vibration detecting sensor 8, sound is insulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound insulation device.

[0002]

2. Description of the Related Art In recent years, the prevention of noise in a living environment has become an important issue due to the increasing density and aggregation of houses in urban areas. Therefore, various sound insulation panels have been used as a means for preventing noise, but at present, satisfactory sound insulation performance is not obtained. For example, a double wall or window glass having an air layer in the middle is used because it is lightweight and has relatively good sound insulation, but there is a low frequency resonance transmission phenomenon due to the spring action of the middle air layer. Therefore, it cannot be said that the sound insulation performance in the middle and low frequency range is sufficient.

Besides this, for example, as shown in FIG.
There is provided a sound insulation device having an active sound insulation effect. This apparatus includes one panel material 1, a vibration detection sensor 8 attached to the panel material 1 to detect vibration of the panel material 1, and an actuator 10 for excitation attached to four positions of the panel material 1. A drive unit 5 for driving the actuator 10 and a noise detection sensor 7 for detecting noise emitted from the noise source 6 are provided, and driven by an electric signal of noise input from the vibration detection sensor 8 and the noise detection sensor 7. The part 5 performs a calculation, and the panel material 1 is excited in a phase opposite to that of the noise to cancel the vibration of the panel material 1 due to the noise. As a result, the vibration of the panel material 1 is stopped and the stationary state is maintained. Is to demonstrate.

[0004]

However, in the above-mentioned conventional sound insulation device, the vibration detection sensor 8 is attached by applying the control force for controlling the panel vibration from the actuator 10 attached to the panel 1. Suppress panel vibration. Therefore, it has the following problems.

In the conventional sound insulation device described above, a control force for reducing the panel vibration at the attachment point of the vibration detection sensor 8 is applied to the panel material 1 by the actuator 10 at the attachment point. In this way, since the range of the panel material 1 to which the vibration control force is input is not a surface but a point, only a specific vibration mode of the panel material 1 is strongly excited, and at the attachment point of the vibration detection sensor 8. Even if the panel vibration is suppressed, it is possible that the panel vibration at a position other than the attachment point increases conversely. Sound insulation is
Since it is determined by the vibration state of the entire panel surface, there is a case where the sound insulation property is adversely reduced by applying the control force as described above.

Therefore, it is an object of the present invention to provide a sound insulation device having high sound insulation performance over a wide frequency range without strong excitation of only a specific vibration mode on the panel surface.

[0007]

In order to solve the above-mentioned problems, a sound insulation device according to the present invention is, firstly, provided with two facing members.
A sound insulation panel having a space hermetically sealed by a sheet of panel material and a peripheral member that closes these peripheral intervals, a speaker that emits sound waves in the hermetically sealed space, a drive unit that drives the speaker, and With respect to the sound insulation panel, a noise detection sensor installed outside the sound insulation panel on the same side as the noise source to detect noise emitted from the noise source, and the sound transmitted through the sound insulation panel among the two panel materials is radiated. And a vibration detection sensor attached to the panel material on the side of the panel for detecting the vibration of the panel material, and controlling the driving force to the speaker using signals from the noise detection sensor and the vibration detection sensor. By doing so, sound insulation is provided.

In order to solve the above-mentioned problems, the sound insulation device according to the present invention is, secondly, a sound insulation panel having a space hermetically sealed by two facing panel members and a peripheral member which closes a peripheral interval between them. A speaker that emits a sound wave in the sealed space, a drive unit that drives the speaker, and a noise that is installed outside the sound insulation panel on the same side as the noise source with respect to the sound insulation panel, A noise detection sensor for detecting, and the noise source with respect to the sound insulation panel is installed outside the sound insulation panel on the opposite side,
A microphone that detects a sound transmitted through the sound insulation panel, and is configured to perform sound insulation by controlling a driving force to the speaker using signals from the noise detection sensor and the microphone. Is.

The material of the sound insulation panel used in the present invention,
The size, shape, mutual distance (= thickness of closed space) between two facing panel materials, etc. are not particularly limited, and may be the same as those of the conventional sound insulation panel. The speaker used in the present invention emits a sound wave into the closed space of the sound insulation panel, and is driven so as to suppress the vibration of the panel material by the sound pressure of the emitted sound wave. As the speaker, a generally used speaker can be used. Although the mounting position and the number of the speakers are not particularly limited, when the shape of the closed space in the sound insulation panel is a rectangular parallelepiped, the speaker is preferably mounted in a corner of the rectangular parallelepiped space or in the vicinity thereof. When a noise is received, a mode of sound pressure distribution occurs inside the closed space of the sound insulation panel, and the corners of the rectangular parallelepiped space always have an antinode of the sound pressure distribution. Therefore, if a speaker is attached to the corner of the rectangular parallelepiped space or its vicinity, the sound can be effectively shielded over a wide frequency range. Most preferably, the speaker is mounted at or near all corners of the rectangular parallelepiped space, but is not limited thereto.

The noise detection sensor used in the present invention is installed outside the sound insulation panel on the same side as the noise source with respect to the sound insulation panel, and detects the noise emitted from the noise source. The noise detected by this noise detection sensor is
Not only the sound itself emitted by the noise source but also the mechanical vibration of the noise source is included. For example, when the noise source is a musical instrument, a machine, or the like, the noise detection sensor may be directly attached to those devices to detect the mechanical vibration of the devices. When the noise source is a device that converts an electric signal into sound, such as an audio device, the noise detection sensor may detect the electric signal corresponding to the noise.

In the vibration detecting sensor used in the present invention, of the two facing panel materials, the panel material on the side where the sound transmitted through the sound insulation panel is radiated (hereinafter referred to as "radiation side panel material"). ) Is attached to, and detects the vibration. The mounting position of the vibration detection sensor on the radiation side panel material is not particularly limited, but it is preferably mounted at the central portion of the radiation side panel material. The panel transmitted sound becomes maximum when the center part of the radiation side panel material vibrates in the vibration mode where the center part is antinode (high radiation efficiency), and vibrates in the vibration mode where the center part becomes the node. This is because the case becomes the smallest (the radiation efficiency is low). However, the present invention is not limited to this, and the vibration detection sensor may be attached to a position other than the central portion of the radiation side panel material. The number of attachments is not limited to one, and may be two or more.

The microphone used in the present invention is installed outside the sound insulation panel on the side opposite to the noise source with respect to the sound insulation panel, and detects the sound transmitted through the sound insulation panel. Therefore, when a microphone is used, the sound transmission through the sound insulation panel itself is the control target for evaluation.
It is a valid configuration. When the microphone is installed outdoors, the microphone may be required to have durability against the elements such as wind and rain. However, when the microphone is installed indoors, such durability problem is small.

The sound insulation device of the present invention may be provided with only one of the vibration detection sensor and the microphone, or may be provided with both of them. The drive unit used in the present invention drives a speaker and uses signals from a noise detection sensor and a vibration detection sensor and / or a microphone to suppress vibration of the radiation side panel material and to transmit sound transmitted through the sound insulation panel. The driving force to the speaker is controlled so that becomes smaller. The vibration of the radiation side panel material and the sound transmitted through the sound insulation panel are evaluated by the input signal from the vibration detection sensor and / or the microphone, and the driving force to the speaker is controlled so that the input signal level becomes low. The control method is not particularly limited, and examples thereof include a method using an arithmetic circuit. The arithmetic circuit is not particularly limited, but for example,
Using a DSP (digital signal processor), Mu
ltiple Error Filtered-The one that constitutes an adaptive digital filter that operates by the XLMS algorithm can be mentioned.

[0014]

When a sound insulation panel having a space hermetically sealed by two panel materials facing each other and a peripheral member closing the peripheral space therebetween receives a sound wave, its transmission loss is due to the mechanical impedance of the panel material, the above hermetically sealed space. It is determined by the thickness of the air layer and its characteristic impedance. The sound wave generated from the noise source first joins the outer surface of the panel material on the noise source side and vibrates the panel material. The vibration of this panel material raises the sound pressure in the closed air layer, and the vibration of the panel material on the opposite side is excited through this, and this vibration causes the outside of the panel on the opposite side of the noise source with respect to the sound insulation panel. Sound transmission occurs due to the emission of sound waves into the space.
Finally, the transmitted sound is emitted by the sound insulation panel 2
Among the panel materials, it is the panel material (radiation side panel material) facing the panel external space on the side opposite to the noise source regarding the sound insulation panel, and the transmitted sound pressure is determined by the vibration state of this radiation side panel material. It Therefore, suppressing the vibration of the radiation side panel material leads to reducing the sound transmitted through the sound insulation panel. In the present invention, the speaker is driven by the drive unit, and the sound wave is emitted from the speaker into the closed space of the sound insulation panel. At that time, the driving force to the speaker is a vibration detection sensor that detects the vibration of the panel material on the side that emits the transmitted sound, and / or a microphone that detects the transmitted sound itself of the sound insulation panel, and the sound emitted from the noise source. The noise detection sensor for detecting the noise is used for control. Then, it becomes possible to control the driving force to the speaker so that the vibration of the panel material on the side that emits the transmitted sound is suppressed by the sound pressure emitted from the speaker. The pressure that suppresses the vibration of the panel material on the transmitted sound radiation side is applied as the pressure distributed on the panel surface by the sound pressure of the sound emitted from the speaker. Therefore, the force that suppresses the vibration of the panel is input in points. Unlike the device, only a specific vibration mode is not strongly excited, and high sound insulation performance is exhibited over a wide frequency range.

[0015]

EXAMPLES Next, examples and comparative examples of the present invention will be shown, but the present invention is not limited to the following examples. Example 1 FIG. 1 shows Example 1. This sound insulation device includes a sound insulation panel having a space 3 sealed by opposed rectangular panel materials 1a and 1b and a peripheral member 2 that closes a peripheral interval between these, four speakers 4, and a drive for driving these speakers. The unit 5 includes a noise detection sensor 7 that detects noise emitted from the noise source 6, and a vibration detection sensor 8 that detects vibration of the panel material 1b. The panel material 1a is a panel material on the side that first receives the noise emitted from the noise source 6. The panel material 1b is a panel material on the side where the sound transmitted through the sound insulation panel is finally radiated to the outside of the panel. The four speakers 4 are embedded in the peripheral member 2 so that sound waves can be emitted from the corners of the rectangular parallelepiped closed space 3 into the closed space 3. The noise detection sensor 7 is installed outside the sound insulation panel on the same side as the noise source 6 with respect to the sound insulation panel. The vibration detection sensor 8 is attached to the central portion of the panel material 1b. The drive unit 5 uses a DSP (digital signal processor) and has a multiple error filter
It has an arithmetic circuit that constitutes an adaptive digital filter that operates according to the d-XLMS algorithm. In this drive unit 5,
The speaker 4, the noise detection sensor 7, and the vibration detection sensor 8 are electrically connected. During operation of the device, an electric signal corresponding to noise is input from the noise detection sensor 7 and an electric signal corresponding to vibration of the panel material 1b is input from the vibration detection sensor 7 to the drive unit 5, respectively. Using the above, the arithmetic circuit of the drive unit 5 performs an operation, and based on the result, the drive unit 5 outputs an electric signal to the speaker 4 to drive the speaker 4. The driving force applied to the speaker 4 is controlled so that the level of the electric signal input from the vibration detection sensor 7 to the driving unit 5 becomes low. The evaluation of the control of the driving force to the speaker 4 is the vibration level of the panel material 1b detected by the vibration detection sensor 8,
This vibration level is fed back from the vibration detection sensor 8 as an electric signal input to the drive unit 5.

Second Embodiment FIG. 2 shows a second embodiment. This sound insulation device includes a sound insulation panel having a space 3 sealed by opposed rectangular panel materials 1a and 1b and a peripheral member 2 that closes a peripheral interval between these, four speakers 4, and a drive for driving these speakers. The unit 5 and the noise detection sensor 7 that detects the noise emitted from the noise source 6 are provided. Up to this point, the configuration is the same as in the first embodiment. In the second embodiment, the microphone 9 is used instead of the vibration detection sensor 8. The microphone 9 is installed outside the sound insulation panel on the side opposite to the noise source 6 (panel material 1b side) with respect to the sound insulation panel, and detects the sound itself transmitted through the sound insulation panel. At the time of operation of the device, an electric signal corresponding to noise is input from the noise detection sensor 7 and an electric signal corresponding to sound transmitted through the sound insulation panel is input from the microphone 9 to the drive unit 5, respectively, and drive is performed using these input signals. The arithmetic circuit included in the unit 5 performs arithmetic operations, and based on the result, the driving unit 5 causes the speaker 4 to operate.
An electric signal is output to drive the speaker 4. The driving force applied to the speaker 4 is controlled so that the level of the electric signal input from the microphone 9 to the driving unit 5 becomes low. The control of the driving force to the speaker 4 is evaluated by the sound pressure level of the sound transmitted through the sound insulation panel detected by the microphone 9,
This sound pressure level is fed back as an electric signal input from the microphone 9 to the drive unit 5. As described above, the sound insulation device according to the second embodiment has a higher sound insulation property because the sound insulation panel transmitted sound itself is controlled to be evaluated.

Next, the sound insulation performance of each of the sound insulation devices of Examples 1 and 2 was examined. Sound insulation performance is 0-500
For noise over the frequency range of Hz, the transmitted sound pressure level when the sound insulation device is activated (ON) and the transmitted sound pressure level when the sound insulation device is not activated (OFF) are measured, and the transmitted sound pressure level is measured. The difference in sound pressure level [= (transmitted sound pressure level when device is OFF)-(transmitted sound pressure level when device is ON)] was obtained and evaluated. The larger this difference is, the higher the sound insulation performance is. The results are shown in the graphs of FIGS. 3 and 5, the solid line represents the transmitted sound pressure level when the device is OFF, and the broken line represents the transmitted sound pressure level when the device is ON. In FIGS. 4 and 6, the solid line is the difference in the transmitted sound pressure level with respect to the noise over the frequency range of 0 to 500 Hz,
“” represents the difference between the transmitted sound pressure levels when the sound insulation device is OFF and when the sound insulation device is ON, with respect to noise having different scales of 1/3 octave centered around 250 Hz.

As a comparative example, the sound insulation performance of the conventional sound insulation device as shown in FIG. 7 was examined by the same method as above. The results are shown when the sound insulation device is OFF and when it is ON.
The difference in the transmitted sound pressure level at each time is shown in FIG. 3 to 6
As shown in FIG. 8, the sound insulation devices of Examples 1 and 2 are
In contrast to the high sound insulation performance over a wide frequency range, the sound insulation device of the comparative example has lower sound insulation performance than the sound insulation devices of the first and second embodiments, and the sound transmission performance is increased by operating the device. However, it was confirmed that there is a frequency band that increases.

[0019]

The sound insulation device according to the present invention has a high sound insulation performance over a wide frequency range without strong excitation of only a specific vibration mode on the panel surface.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram illustrating a first embodiment of a sound insulation device.

FIG. 2 is a schematic explanatory view showing a second embodiment of the sound insulation device.

FIG. 3 is a graph showing the transmitted sound pressure level when the sound insulation device of Example 1 is activated and the transmitted sound pressure level when the device is not activated.

FIG. 4 is a graph showing a difference between a transmitted sound pressure level when the sound insulation device of Example 1 is operated and a transmitted sound pressure level when the device is not operated.

FIG. 5 is a graph showing the transmitted sound pressure level when the sound insulation device according to the second embodiment is activated and the transmitted sound pressure level when the device is not activated.

FIG. 6 is a graph showing a difference between a transmitted sound pressure level when the sound insulation device of Example 2 is operated and a transmitted sound pressure level when the device is not operated.

FIG. 7 is a schematic explanatory diagram illustrating a conventional example of a sound insulation device.

FIG. 8 is a graph showing a difference between a transmitted sound pressure level when the sound insulation device of the conventional example is operated and a transmitted sound pressure level when the device is not operated.

[Explanation of symbols]

 1a Panel material 1b Panel material 2 Peripheral member 3 Closed space 4 Speaker 5 Drive part 6 Noise source 7 Noise detection sensor 8 Vibration detection sensor 9 Microphone

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuya Sueto 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (2)

[Claims] 1. A sound insulation panel having a space hermetically sealed by two facing panel members and a peripheral member that closes a peripheral interval between these panel members, a speaker that emits a sound wave in the hermetically sealed space, and the speaker. A drive unit for driving the sound insulation panel, a noise detection sensor that is installed outside the sound insulation panel on the same side as the noise source with respect to the sound insulation panel, and detects noise emitted from the noise source; The sound transmitted through the panel is attached to the panel material on the side where the sound is radiated, and a vibration detection sensor for detecting the vibration of the panel material is provided, using signals from the noise detection sensor and the vibration detection sensor, A sound insulation device adapted to insulate sound by controlling a driving force applied to the speaker. 2. A sound insulation panel having a space hermetically sealed by two facing panel materials and a peripheral member that closes a peripheral interval between these panel materials, a speaker that emits a sound wave in the hermetically sealed space, and the speaker. A drive unit for driving the sound insulation panel, a noise detection sensor that is installed outside the sound insulation panel on the same side as the noise source with respect to the sound insulation panel, and detects noise emitted from the noise source; and the noise source with respect to the sound insulation panel. A microphone installed outside the sound insulation panel on the side for detecting the sound transmitted through the sound insulation panel, and controlling the driving force to the speaker using signals from the noise detection sensor and the microphone. A sound insulation device designed to insulate sound.