Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
  • A47L9/0081—Means for exhaust-air diffusion; Means for sound or vibration damping
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
  • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
  • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/02—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators
  • G10K11/04—Acoustic filters ; Acoustic resonators

Definitions

• the conventional noise reduction device requires two filters and two resonance chambers, the shape of the device is large and complicated. As a result, it was difficult to incorporate them into home appliances, which was a problem. Also, since many components are required, the production cost is high and this is a problem.
• FIG. 1 is a side sectional view showing a vacuum cleaner to which the noise reduction device according to Embodiment 1 is applied.
• FIG. 2 is a perspective view showing the shape of the sound-heat conversion hole.
• Figures 3 (A) and 3 (B) are graphs showing the actual measurement results of the morning and evening noise.
• FIG. 4 is a front view showing the appearance of the noise reduction plate.
• FIG. 5A is a cross-sectional view taken along line AA in FIG. (B) is a cross-sectional view taken along line BB in FIG.
• FIG. 6 is a side sectional view showing a vacuum cleaner to which the noise reduction device according to Embodiment 2 is applied.
• FIG. 8 is a front view showing the appearance of the noise reduction plate.
• FIG. 11 is a cross-sectional view showing an example in which the noise reduction device according to Embodiment 5 is incorporated in an airflow path.
• FIG. 1 is a side sectional view showing a vacuum cleaner to which the noise reduction device 10 according to Embodiment 1 is applied.
• the vacuum cleaner 1 has an inlet 3 to which a hose 2 for sucking dust is attached, a dust collecting chamber 4 provided behind the inlet 3 for collecting dust, A noise reduction system installed behind the dust collection chamber 4 to generate airflow for sucking dust, and a noise reduction system located behind the motor collection room 5 to reduce the noise generated by the motor
• the apparatus includes a device 10 and an exhaust port 6 disposed behind the noise reduction device 10 and discharging air and a flow that have passed through the noise reduction device 10.
• a paper park 7 is attached to the dust collection chamber 4, and the dust sucked through the intake port 3 is collected in a paper bag 7.
• the motor 5 rotates at a very high speed of 30,000 to 40,000 to rotate the vacuum cleaner 1, and the rotation of the motor 5 is controlled by an operation switch provided on the hose 2. It is controlled to move in accordance with the operation mode of the unit (not shown).
• the noise reduction device 10 includes a noise reduction plate 11 arranged opposite to the motor 5, and a plurality of sound-to-heat conversion holes '12 formed in the noise reduction plate 11 for converting acoustic energy into heat energy. It has. Since these sound-to-heat conversion holes 12 are through holes, the airflow generated by driving the motor 5 passes through the sound-to-heat conversion holes 12 and reaches the exhaust port 6. Each sound-to-heat conversion hole 12 has a cylindrical shrinkage chamber 13 provided on the side of the motor 5 and a cylindrical shrinkage chamber 13 provided on the side of the exhaust port 6 (the opposite side to the side 5). An expansion chamber 14 is provided.
• the hole width (second hole width) of the expansion chamber 14 is configured to be wider than the hole width of the contraction chamber 13 (first hole width).
• the contraction chamber 13 and the expansion chamber 14 are not limited to a columnar shape, but may be a prismatic shape, a truncated cone shape, or a truncated pyramid shape.
• the sound energy conversion hole 12 can convert acoustic energy of noise into heat energy based on the following principle. That is, when a noise sound wave enters the sound-heat conversion hole 12, the sound wave is first narrowed down in the contraction chamber 13. After that, the sound wave enters the expansion chamber 14. However, since the hole width of the expansion chamber 14 is wider than the hole width of the contraction chamber 13, the once narrowed sound wave expands at a stretch. This expansion converts the acoustic energy of the noise into thermal energy. As a result, the output sound pressure level of the noise can be effectively reduced.
• the noise that can be reduced by the sound-heat conversion holes 12 is limited to sounds in a predetermined frequency band. The frequency band that can be reduced is specified by the shape of the sound-heat conversion hole 12.
• the hole width of the contraction chamber 13 is d 0
• the depth of the contraction chamber 13 is L 0
• the volume of the expansion chamber 14 is V
• the light speed is c
• the frequency f 0 that can be reduced is
• the noise generated from the noise source such as Moya 5 is composed of a random sound and a peak sound, and the random sound is also separated from the peak sound in the sense of hearing and can be heard as harsh noise. Therefore, by setting the frequency of the peak sound included in the noise as the evening gate and forming the sound-heat conversion hole 12 with the dimensions derived from the above equation, the peak sound can be removed from the noise, and the sound quality of the noise can be reduced. Is effectively improved.
• the peak sound of motor 5 is the blade passing frequency sound of the rotating fan.
• the wing passing frequency sound (ie, peak sound) is 4800 Hz.
• a peak sound is generated at 9600 Hz, which is twice the frequency of 4800 Hz.
• Fig. 3 (A) shows the result of the actual measurement of the noise of Mo overnight. It can be seen from these actual measurements that there are peak sounds at 4800 Hz and 9600 Hz.
• the sound-heat conversion hole 12a has a contraction chamber 13a with a hole width of 3.1 mm, a contraction chamber 13a with a depth of 2.1 mm, an expansion chamber 14a with a hole width of 12.0 mm, and an expansion chamber 14
• the depth of a is 2.1 mm.
• the sound-to-heat conversion hole 12b has a contraction chamber 13b with a hole width of 3.2 mm, a contraction chamber 13b with a depth of 2.1 mm, and an expansion chamber 14b with a hole width of 6.0 mm.
• the depth of chamber 14b is 2. lmm.
• the two types of sound-to-heat conversion holes 1 2a 3 1 2b provided on the noise reduction plate 11 eliminate two peak sounds of 480 Hz and 960 Hz. be able to.
• a smooth noise characteristic without peak sound was obtained, and the sound quality of the noise was greatly improved.
• the sound-heat conversion holes 12 having different hole widths are not limited to two types, and may be three or more types. In this case, three or more peak sounds can be removed.
• the noise reduction device 10 is composed of the noise reduction plate 11 and the sound-heat conversion holes 12, the configuration of the device is simplified, and A reduction in size and weight is realized. As a result, it can be easily incorporated into household electric appliances such as vacuum cleaners, and it is possible to sell low-noise and excellent household electric appliances at low cost.
• a sound-absorbing room which is a closed space, is formed between the noise reduction plate 11 and the motor 5, so that the sound wave of the noise generated from the motor 5 is Without leaking, the sound propagates through the sound reduction chamber, and the peak sound can be reliably removed at any of the plurality of sound-to-heat conversion holes 12 provided in the noise reduction plate 11.
• the present embodiment has a simple configuration in which the noise reduction plate 11 surrounds the periphery of the motor 5, so that if there is a space slightly larger than the motor 5, noise reduction is possible.
• Device 20 can be incorporated. As a result, it becomes easy to incorporate the noise reduction device 20 into a household electric appliance such as a vacuum cleaner, and it is possible to provide an excellent electric appliance with low noise at low cost.
• a ventilation port 3 2 is provided in the noise reduction plate 11 located below the motor 5 and the airflow generated by the motor 5 passes through the ventilation port 32 and is discharged from the exhaust port 6.
• the plurality of sound-to-heat conversion holes 12 formed in the noise reduction plate 11 have two types of sound-to-heat conversion holes 12a and 12b having different hole widths.
• the sound-heat conversion hole 12a can remove the peak sound of 480 Hz
• the sound-heat conversion hole 12b can remove the peak sound of 960 Hz. Therefore, the sound waves of the noise propagating in the sound-absorbing chamber enter the sound-to-heat conversion holes 12a and 12b, so that the two types of peak sounds are surely removed (that is, the peak sound). Sound energy is converted to heat energy). As a result, the sound quality of the noise generated at the motor 5 is improved, and the output sound pressure level of the noise can be effectively reduced.
• the box shape formed by the plurality of noise reduction plates 11 is not limited to a rectangular parallelepiped shape, but may be a cylindrical shape or a hemispherical shape.
• a noise reduction plate 11 may be arranged in front of the motor 5. In this case, the six surfaces around the motor 5 are covered with the noise reduction plates 1 and 1, and the noise reduction effect is further improved.
• FIG. 10 is a cross-sectional view showing an example in which noise reduction device 40 according to Embodiment 4 is arranged on airflow path 41. Note that the same or equivalent components as those in Embodiment 1 are denoted by the same reference numerals and description thereof is omitted.
• the noise reduction device 40 is formed of a noise reduction plate 11 and a noise reduction plate 11 arranged opposite to the air flow, and converts acoustic energy into heat energy. And a plurality of sound heat conversion holes 12.
• Each sound-to-heat conversion hole 12 includes a contraction chamber 13 provided on the airflow incident side and an expansion chamber 14 provided on the airflow exit side.
• each sound-heat conversion hole 12 is a through hole, and is configured such that the hole width of the expansion chamber 14 is wider than the hole width of the contraction chamber 13.
• the noise reduction device 40 Since the noise reduction device 40 is configured as described above, the sound wave of the noise superimposed on the air flow enters each sound-to-heat conversion hole 12 formed in the noise reduction plate 11 to reduce the noise.
• the peak sound is removed (ie, the sound energy of the peak sound is converted to heat energy).
• the noise superimposed on the airflow The sound quality of the sound is improved, and the output sound pressure level of the noise can be effectively reduced.
• the noise reduction device 50 is formed on the noise reduction wall 52 and the noise reduction wall 52 that constitute at least a part of the air flow path 51, and heats the acoustic energy.
• a plurality of sound-to-heat conversion holes 12 for converting into energy are provided.
• Each sound-to-heat conversion hole 12 includes a contraction chamber 13 provided on the airflow incident side and an expansion chamber 14 provided on the airflow exit side.
• each sound-heat conversion hole 12 is a bottomed hole, and is configured such that the hole width of the expansion chamber 14 is wider than the hole width of the contraction chamber 13.
• the noise reduction device 50 Since the noise reduction device 50 is configured as described above, the sound wave of the noise superimposed on the air flow enters each sound-to-heat conversion hole 12 formed in the noise reduction wall 52, and the noise is reduced.
• the peak sound is removed (ie, the acoustic energy of the peak sound is converted to thermal energy).
• the sound quality of the noise superimposed on the airflow is improved, and the output sound pressure level of the noise can be effectively reduced.
• the noise reduction wall 52 and the sound-heat conversion hole 1 2 constitutes the noise reduction device 50, so that the configuration of the device is simplified, and the device can be reduced in size and weight. As a result, it becomes easy to incorporate this device into a hose of a vacuum cleaner, etc., and it becomes possible to provide low-noise and excellent home appliances at low cost.
• the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention. Further, in the above-described embodiment, an example in which the present invention is applied to a vacuum cleaner has been described. However, the present invention is not limited to a vacuum cleaner, and can be applied to all devices that generate sound, such as a ventilation fan and a vacuum cleaner. is there. Industrial applicability
• the noise reduction device according to the present invention is applicable to all devices that generate sound, such as ventilation fans and vacuum cleaners.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Multimedia (AREA)
• Mechanical Engineering (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)
• Soundproofing, Sound Blocking, And Sound Damping (AREA)
• Exhaust Silencers (AREA)
• Electric Suction Cleaners (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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ID=33027698

Family Applications (1)

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Citations (4)

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• 2003
  • 2003-03-17 JP JP2003071698A patent/JP2004279779A/ja active Pending
• 2004
  • 2004-03-12 CN CNB2004800001615A patent/CN100397483C/zh not_active Expired - Fee Related
  • 2004-03-12 KR KR1020067025739A patent/KR20070005740A/ko not_active Application Discontinuation
  • 2004-03-12 WO PCT/JP2004/003311 patent/WO2004083799A1/ja not_active Application Discontinuation
  • 2004-03-12 KR KR10-2004-7016732A patent/KR20050006170A/ko active Application Filing
• 2006
  • 2006-04-20 HK HK06104730.1A patent/HK1084442A1/xx not_active IP Right Cessation

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