JPH053843A - Cleaner - Google Patents

Abstract

PURPOSE:To provide the cleaner which can reduce remarkably even a noise in a low frequency area of <=1kHz especially which cannot be reduced enough by a conventional technique, at the time of reducing a noise of the cleaner. CONSTITUTION:In an exhaust chamber 12 in which an air blower 15 is contained, an exhaust duct 13 is connected and provided, and an active muffling device constituted of a noise detecting microphone 16 and a loudspeaker 17, a monitor microphone 18 and a control circuit 19 is integrated into the exhaust chamber 12 and the exhaust duct 13. An exhaust sound generated by driving the air blower 15 is propagated through the exhaust duct 13 from the exhaust chamber 12 and emitted to the outside. In this case, by the microphone 16, a noise is detected, and from the loudspeaker 17, a sound wave of a waveform calculated by the control circuit 19 so as to become a just reverse phase and the same amplitude to and as the detected sound wave is emitted. As a result, both the sound waves interfere with each other, and a noise level emitted to the outside from an exhaust port 14 is reduced greatly. In this regard, in this case, the microphones 16, 18 and the loudspeaker 17 do not protrude into the exhaust duct 13, therefore, in the exhaust duct 13, a failure by generation of a secondary noise caused by themselves is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum cleaner, and more particularly to a vacuum cleaner having a function of effectively reducing noise.

[0002]

2. Description of the Related Art As a vacuum cleaner having a noise reducing function as described above, for example, one disclosed in Japanese Patent Laid-Open No. 61-179121 is known. 5 and 6 are a side sectional view and a bottom sectional view showing the vacuum cleaner disclosed in the above publication.
As shown in the figure, inside the main body case 1, the dust collection chamber 1
0, an exhaust chamber 2 having an electric blower 5 built therein, and an exhaust duct 3 having an exhaust port 4 are continuously provided. By driving the electric blower 5, dust and air sucked together with the dust are collected in a dust collecting chamber 10, It is discharged to the outside of the machine through the exhaust chamber 2, the exhaust duct 3, and the exhaust port 4. In this case, the noise caused by the air flow in the electric blower 5 and the main body is attenuated while passing through the exhaust duct 3, thereby reducing the noise during exhaust. In another conventional device, the exhaust air from the electric blower is guided to the bottom end and discharged from both sides of the main body case part on both sides of the main body case or the dust collection chamber side to disperse the exhaust sound. However, technology that attempts to reduce noise has also been proposed.

[0003]

In the conventional vacuum cleaner as described above, the noise is absorbed by the sound absorbing material in the exhaust duct, or the distance is attenuated by increasing the distance from the noise source to the exhaust port. Is being reduced,
The frequency range of noise that can be reduced by such technology is 1
The noise is higher than KHz, and the noise in the lower frequency range is still left, and it is the actual situation that sufficient noise reduction cannot be achieved. Therefore, an object of the present invention is to provide a cleaner having a function capable of effectively reducing noise regardless of the height of the frequency range.

[0004]

In order to achieve the above-mentioned object, the main means adopted by the present invention is the gist of the present invention. However, by driving an electric blower housed in the exhaust path, dust and dust are removed. In a vacuum cleaner that discharges sucked air to the outside of the machine through a dust collection chamber, an exhaust path, and an exhaust port,
Sound detecting means for detecting a sound generated by driving the electric blower, and sound generating means for generating a sound having a waveform that cancels this sound by interfering with the sound detected by the sound detecting means. The vacuum cleaner according to the above aspect is embedded along the exhaust path so that the inner surface of the exhaust path is a smooth surface.

[0005]

In general, noise in the exhaust passage propagates through the exhaust passage and is radiated from the exhaust port to the outside. However,
In the vacuum cleaner according to the present invention, the sound generated by driving the electric blower is detected by the sound detecting means, and the waveform having the opposite phase and the same amplitude that cancels the sound by interfering with the detected sound. Sound is emitted from the sounding means. As a result, both sound waves interfere with each other, and the level of noise radiated from the exhaust port to the outside is significantly reduced. In this case, since the sound detecting means and the sounding means do not project into the exhaust path, the sound is erroneously detected due to the generation of secondary noise caused by these in the exhaust path, and the sound is muted by the sound that does not follow the substance. Effective silencing can be performed without causing defects such as defects.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention. 1 is a cross-sectional view showing a schematic structure of a vacuum cleaner according to an embodiment of the present invention, FIG. 2 is a detailed view of an arrow A portion in FIG. 1, and FIG. 3 is a detail of an arrow B portion in FIG. FIG. 4 and FIG. 4 show the structure of another embodiment applicable to the portion indicated by the arrow A in FIG. 1 and are equivalent to FIG. In the vacuum cleaner according to this embodiment, as shown in FIGS.
A dust collection chamber 20, an exhaust chamber 12 having an electric blower 15 built therein, and an exhaust duct 13 having an exhaust port 14 are continuously provided. By driving the electric blower 15, dust and air sucked together with dust are collected. Chamber 20, exhaust chamber 12, exhaust duct 1
3, exhausted to the outside of the machine through the exhaust port 14. in this case,
The exhaust duct 13 can be arranged at any of the side portion and the bottom portion of the main body case 11, and the total length thereof is the noise detection microphone 16 (sound detecting means) described later.
From the relationship between the howling prevention between the speaker 17 and the speaker 17 and the calculation speed in the control circuit 19, about 70 to 80 cm is required. Therefore, the exhaust duct 13 is not limited to the straight pipe duct, as shown in FIG. A curved pipe shape is effective. Thereby, the vacuum cleaner body can be downsized. The noise detection microphone 16 is for detecting the sound generated by driving the electric blower 15, and is installed inside the exhaust chamber 12 or near the inlet of the exhaust duct 13. The speaker 17 is for generating a sound that cancels the sound generated when the electric blower 15 is driven, and is installed near the exhaust port 14. In this case, the sound emitted from the speaker 17 corresponds to a sound having a waveform with the opposite phase and the same amplitude that cancels this sound by interfering with the sound detected by the noise detection microphone 16. Then, this waveform is calculated by the control circuit 19 installed inside the upper surface of the main body case 11, for example.

By the speaker 17 and the control circuit 19,
A sounding unit is configured to generate a sound having a waveform that cancels this sound by interfering with the sound detected by the noise detection microphone 16. Further, in the vacuum cleaner according to the present embodiment, the monitor microphone 18 connected to the control circuit 19 is installed near the exhaust port 14. In this case, the noise detection microphone 16, the monitor microphone 18, and the speaker 17 are embedded along the exhaust duct 13 so that the inner surface of the exhaust duct 13 is a smooth surface. This is the microphone 1
6, 18 and the speaker 17 project into the exhaust duct 13 to cause a turbulent air condition locally, and secondary noise caused by the erroneous detection of sound and muffling by sounding a waveform that does not follow the substance. It is based on consideration that defects such as defects do not occur. That is, as shown in FIGS. 2 and 3, the microphones 16 and 18 and the speaker 17 are arranged outside the exhaust duct 13, and the sound detection part and the sounding part thereof are formed in the openings 13a and 13b.
Through the exhaust duct 13. The main body parts of the microphones 16 and 18 and the speaker 17 are box 2 attached to the outer surface of the exhaust duct 13.
The microphones 16 and 18 are covered with 1 and 22 and are attached to the box 21 via a vibration isolator 23. The speaker 17 is directly screwed to the exhaust duct 13. The openings 13a and 13b of the exhaust duct 13 are covered with a sheet 24 (thin film, felt, etc.) that does not significantly affect the acoustic characteristics so that the inner surface of the exhaust duct 13 becomes a substantially smooth surface. .. It should be noted that, instead of the mounting structure of the microphones 16 and 18 as described above, as shown in FIG. 4, a probe tube 25 made of a vibration isolator is provided through the side wall portion of the exhaust duct 13 so that the The microphones 16 and 18 may be attached to the box 21. In the vacuum cleaner configured as described above, the noise (mainly exhaust noise and noise caused by the rotation of the fan) generated by driving the electric blower 15 propagates through the exhaust chamber 12 and the exhaust duct 13. Is radiated to the outside from the exhaust port 14.
At this time, the sound wave near the sound source is detected by the noise detection microphone 16. When the sound wave reaches the position of the speaker 17 in the exhaust duct 13, a sound wave having a phase opposite to the sound wave and having the same sound pressure is generated.
Emitted more. Then, the two sound waves interfere with each other, and only the sound waves whose sound pressure is significantly reduced are radiated to the outside from the exhaust port 14. At this time, the above monitor microphone 1
At 8, the reduction amount of the sound pressure after the muffling is monitored, and the result is fed back to the control circuit 19. By this,
The output signal to the speaker 17 is adjusted so that the muffling effect is maximized. In this case, since the microphones 16 and 18 and the speaker 17 do not project into the exhaust duct 13 as described above, erroneous detection due to the generation of secondary noise caused by themselves in the exhaust duct 13 does not follow the substance. Effective muffling can be performed without causing problems such as muffling failure due to pronunciation. Here, the noise frequency f having a reducing effect by the above configuration is expressed by the following equation (1) with respect to the minor axis D of the exhaust duct 13. f <C / 2D (Hz) (1) C: sound velocity (m / s) D: short diameter of exhaust duct (m) From the above formula (1), it is effective for frequencies below a predetermined limit frequency range. It is clear that there is. Therefore, it is possible to obtain a great silencing effect even in the low frequency range, which cannot be sufficiently silenced by the conventional vacuum cleaner.

[0008]

Since the vacuum cleaner according to the present invention is configured as described above, the conventional vacuum cleaner is not sufficiently effective in reducing noise in a relatively low frequency range, while it has a large effect. A reduction effect can be achieved. In this case, since the sound detecting means and the sound producing means do not project into the exhaust path as described above, the erroneous detection of the sound due to the generation of the secondary noise due to the self in the exhaust path, and the realization of the sound does not occur. Effective muffling can be performed without causing problems such as muffling failure due to pronunciation. Therefore, even in the early morning or late at night, it is possible to clean the surrounding area without hesitation.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic structure of a vacuum cleaner according to an embodiment of the present invention.

FIG. 2 is a detailed view of an arrow A portion in FIG.

FIG. 3 is a detailed view of an arrow B portion in FIG.

FIG. 4 is a view showing another example structure applicable to the arrow A portion in FIG. 1, and is a view equivalent to FIG.

FIG. 5 is a side sectional view of a conventional vacuum cleaner.

FIG. 6 is a bottom sectional view of the conventional vacuum cleaner.

[Explanation of symbols]

 11 ... Main body case 12 ... Exhaust chamber 13 ... Exhaust ducts 13a, 13b ... Opening 14 ... Exhaust port 15 ... Electric blower 16 ... Noise detection microphone (sound detection means) 17 ... Speaker 18 ... Monitor microphone 19 ... Control circuit 20 ... Dust collection Chamber 21.22 ... Box 23 ... Anti-vibration material 24 ... Sheet 25 ... Probe tube

Claims (1)

Claims: 1. A cleaning system for driving an electric blower housed in an exhaust path to discharge dust and air sucked together with dust through a dust collection chamber, an exhaust path, and an exhaust port to the outside of the machine. Sounding means for detecting a sound generated by driving the electric blower, and a sound generation for generating a sound having a waveform that cancels this sound by interfering with the sound detected by the sound detecting means. The cleaning means is embedded along the exhaust path so that the inner surface of the exhaust path becomes a smooth surface.