JPH06202670A - Oundproof ventilation device - Google Patents

Abstract

PURPOSE:To provide the ventilation device which saves the space and has high soundproof effect on sounds in a wide frequency band. CONSTITUTION:This device consists of a ventilation flue connecting an intake 3 whose internal surface consists of a sound absorbing surface to an outlet 4, a speaker 2 for sound elimination which is arranged almost in the center of the ventilation flue, and a control circuit 12. The control circuit 12 inverts the phase of the input signal to an acoustic speaker 6 for listening to music in the room and the signal is delayed by a digital filter 9; and high frequency components are removed by a low-pass filter 10 and a drive amplifier 11 for driving controls the speaker 2 for sound elimination. For a low frequency range, a sound is eliminated by adding an opposite-phase sound, so the ventilation device which requires no large space and has high soundproof effect on sound in a wide frequency range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation device having a high soundproof effect over a wide frequency band.

[0002]

2. Description of the Related Art In recent years, full-scale AV rooms have become widespread in homes due to the development of audiovisual equipment. However, in order to enjoy powerful loud sound, soundproofing work for improving the sound insulation of the room is performed. is necessary. The more accurate soundproofing works, the more tightly sealed the room becomes, and it becomes necessary to install a ventilation device to take in fresh air into the room and discharge excess heat. However, if a normal ventilation fan is used, since the ventilation port penetrates the sound insulation wall, the sound passes through without being used in a soundproof room. Therefore, various soundproof type ventilation devices have been proposed.

Hereinafter, an example of a conventional soundproof ventilation device will be described with reference to the drawings. FIG. 2 is a sectional view showing the structure of a conventional soundproof ventilation device. In FIG.
The ventilator main body 31 includes a fan 32 and a motor 33 for rotating the fan 32, and is fitted and fixed in a hole formed in a wall 37 of the room. An aesthetically breathable grille 34 is attached to the indoor side of the main body 31, and a soundproof hood 35 having a sound absorbing material 35a attached to the inner surface is attached to the outdoor side. When the motor 33 is driven to rotate the fan 32, the device takes in air from the indoor side through the grill 34. The air coming out of the hole 31a on the back surface of the main body 31 receives the soundproof hood 35
Is bent at a right angle by and is discharged from the exhaust port 36. Due to the action of the soundproof hood 35 having a sound absorbing material attached to the inner surface thereof, it is possible to prevent sound in the room at a particularly high frequency while performing ventilation.

[0004]

The ventilator having such a conventional structure has the following problems. That is,
In this configuration, the air inside and outside the room is always in communication,
The effect of the soundproof hood 35 is due to the sound attenuation due to the curved flow path and the sound absorbing effect due to the sound absorbing material 35a attached to the inner surface. The effect is usually up to about 500 Hz, and the sound of lower frequency is obtained. On the other hand, there was no effect.

In order to insulate even lower frequency sounds, a large muffling duct is required, which requires a large space and complicates the apparatus, and is not suitable for general household use.

The present invention solves the above-mentioned problems.
It is an object of the present invention to provide a ventilation device that does not take up space and can be easily installed, and has a high soundproof effect for sounds in a wide frequency band.

[0007]

In order to achieve the above object, a soundproof ventilation device of the present invention includes a phase inverting circuit for inverting a phase of a signal input to an acoustic speaker installed in a room, and the phase inverting circuit. A digital filter that delays the output signal of the circuit, a low-pass filter that removes high frequency components from the output signal of the digital filter, and an almost central position of the ventilation passage that connects the intake port to the exhaust port, the inner surface of which is a sound absorbing surface And a speaker for noise reduction that reproduces the output signal of the low-pass filter.

The transfer function of the digital filter is set to be H / G, where H is the transfer function from the music speaker to the exhaust port and G is the transfer function G from the muffling speaker to the exhaust port. .

[0009]

In the above-mentioned structure of the present invention, first, from the exhaust port,
When the airflow flows toward the intake port, the high frequency components are silenced by the sound absorbing material on the inner surface of the ventilation passage. As for the low-pitched sound component, the sound-absorbing material of the ventilation passage is not enough and passes through. The reproduced sound generated from the speaker crosses the room and enters the ventilation path. When passing in front of the muffling speaker, the speaker emits a sound of opposite phase to mute the sound from the music speaker. Therefore, it is possible to obtain a ventilation device having high sound insulation over a wide frequency range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A ventilation device of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the principle structure of a ventilation device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a ventilation path connecting the intake port 3 and the exhaust port 4, the inner wall of which is made of a sound absorbing material. Reference numeral 2 is a muffling speaker provided near the center of the ventilation passage. A blower 5 sends the air in the listening room 13 to the outside of the room for ventilation. Reference numeral 6 denotes a music speaker for listening to music, which is driven by a drive amplifier 7. Reference numeral 12 denotes a phase inversion circuit 8 that inverts the phase of the input signal of the music speaker 6, a digital filter 9 that delays the time when the sound reaches from the music speaker 6 to the position of the muffling speaker 2 provided in the ventilation path. The control circuit includes a low-pass filter 10 excluding high-frequency components, and a drive amplifier 11 for driving the muffling speaker 2.

The delay time of the digital filter 9 is H / G when the transfer function from the music speaker 6 to the exhaust port 4 is H and the transfer function G from the muffling speaker 2 to the exhaust port 4 is H / G. To be configured.

The sound emitted from the music speaker 6 becomes an I × H sound at the exhaust port 4. However, I is a music signal input to the input terminal 14. On the other hand, the sound emitted from the muffling speaker 2 has passed through the phase inversion circuit 8, so the exhaust port 4
Then, −I × (H / G) × G. These synthetic sound pressures are added up to give I × H−I × (H / G) × G = 0.
That is, the sound emitted from the music speaker is muted and does not leak outside the room. This does not apply to sounds in the low frequency range generated in the listening room except for the music speaker. In the high range, this theory cannot be applied due to the disturbance of the speaker characteristics. The high sound range is silenced by the sound absorbing material formed on the inner surface of the ventilation passage.

As described above, according to this embodiment, since the inside and outside of the room are ventilated through the ventilation passage having the inner wall made of the sound absorbing material, the sound absorbing material in the ventilation passage silences the high frequency sound. Further, since the low-pitched sound range can be silenced by the sound deadening speaker provided in the vicinity of the center of the ventilation path, a high sound deadening effect can be realized for a wide frequency band sound, and a large silencer is not required.

In the above description, an example is mainly used as a discharge device for discharging the air in the room, but as described above, the suction device can be used in the same manner.

[0016]

EFFECTS OF THE INVENTION As is apparent from the above embodiments, the present invention is directed to a ventilation passage that connects an intake port and an exhaust port, the inner surface of which is made of a sound absorbing material, and a muffler that is provided substantially in the center of the ventilation channel. It is composed of a speaker and its control circuit. In the high frequency range, the sound absorbing material in the ventilation passage is used to mute the sound, and in the low frequency range, the sound of the music speaker is muffled by adding the sound of the opposite phase to the sound by the sound absorption speaker and the control circuit. Therefore, it is possible to provide a ventilator having a high soundproof effect against sounds in a wide frequency band.

[Brief description of drawings]

FIG. 1 is a sectional view showing the principle configuration of a ventilation device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a conventional ventilation device.

[Explanation of symbols]

 1 Ventilation path 2 Silence speaker 3 Inlet port 4 Exhaust port 5 Blower 6 Music speaker 7 Music speaker drive amplifier 8 Phase inversion circuit 9 Digital filter 10 Low pass filter 11 Silence speaker drive amplifier 12 Control circuit 13 Audition room

Claims (2)

[Claims] 1. A phase inversion circuit that inverts the phase of a signal input to an acoustic speaker installed in a room, a digital filter that delays an output signal of the phase inversion circuit, and a high frequency band from the output signal of the digital filter. It consists of a low-pass filter that removes components, and a sound-reducing speaker that is installed almost at the center of the ventilation path that connects the intake port to the exhaust port, the inner surface of which is composed of a sound-absorbing surface, and that reproduces the output signal of the low-pass filter. Soundproof ventilation system. 2. The transfer function of the digital filter is H / G, where H is the transfer function from the music speaker to the exhaust port and G is the transfer function G from the muffling speaker to the exhaust port. The soundproof ventilation device according to claim 1, wherein the ventilation device is set.