JP2015045232A - Electric blower assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric blower assembly capable of precisely reducing noises generated by an electric blower.SOLUTION: An electric blower assembly 1 comprises: an electric blower 1A having an electric motor 8 with a rotation shaft 8A, and a centrifugal fan 4 provided on the rotation shaft 8A of the electric motor 8; and a sound-proof wall 16 provided around the electric blower 1A. A large number of first through holes 19 are formed on the sound-proof wall 16, and an enclosure part 36 that is one part of a casing 35 is provided outside the sound-proof wall 16. A resonance chamber 37 defined by the sound-proof wall 16 and the enclosure part 36 is also provided. When sound waves are propagated in the resonance chamber 37 from the first through holes 19, air in the resonance chamber 37 is resonated with a frequency component corresponding to a resonance frequency in the sound waves, and acts to cancel sonic vibration. Therefore, a resonance frequency component in the sound waves is cancelled, and noises propagated to outside can be reduced.

Description

  The present invention relates to an electric blower assembly, and more particularly to an electric blower assembly with reduced noise.

  Conventionally, in this type of electric blower assembly, a high-frequency sound having a protruding sound pressure level generated by an impeller (corresponding to the fan of the present invention) is greatly reduced near the sound source to reduce noise. Known (for example, Patent Document 1). This electric blower resonates with the sound of a frequency determined by the depth of the short recess by providing a silencer provided with a short recess having a depth in the radial direction on the side of the motor near the exhaust port of the fan case. The sound is silenced by the effect, and the sound pressure level at which the high frequency sound protrudes is reduced without lowering the efficiency of the electric blower.

JP 2007-113476 A

  According to Patent Document 1, when noise including high-frequency sound generated by an impeller leaks from the exhaust port on the side of the fan case, the noise is propagated toward the exhaust port through the air passage between the soundproof cylinder and the silencer. Although it is reduced by resonating at the concave portion formed in the silencer, there is a possibility that a part of the soundproof wall may be vibrated and propagated before being reduced by the resonance of the concave portion. In addition, noise, including high-frequency sound, is partially transmitted through the inside of the motor and discharged from the exhaust port provided in the frame, so that the noise is propagated to the outside without being reduced. Noise reduction was anxious.

  Therefore, the problem to be solved by the present invention is to provide an electric blower assembly that can reliably reduce noise such as high-frequency sound generated by the electric blower.

  The electric blower assembly of the invention of claim 1 includes an electric blower including an electric motor having a rotation shaft, a fan provided on the rotation shaft of the electric motor, and a soundproof wall provided around the electric blower. In the electric blower assembly, a plurality of through holes are formed in the soundproof wall, a surrounding portion is provided outside the soundproof wall, and a resonance chamber defined by the soundproof wall and the surrounding portion is provided. And

  An electric blower assembly according to a second aspect of the present invention is the electric blower assembly according to the first aspect, wherein a sound absorbing material is provided in the resonance chamber.

  The electric blower assembly according to a third aspect of the present invention is the electric blower assembly according to the first or second aspect, wherein a frame having an exhaust port is provided inside the soundproof wall.

  According to the first aspect of the present invention, when a sound wave generated by the electric blower is propagated from the through hole into the resonance chamber, it corresponds to a resonance frequency determined by a diameter of the through hole, a volume of the resonance chamber, or the like. The air in the vicinity of the through hole is repeatedly compressed and expanded by the frequency component in the sound wave, and the vibration energy of a specific frequency is lost due to the resistance friction at this time, so that the noise transmitted to the outside can be reduced.

  According to the second aspect of the present invention, vibration energy of sound waves other than the resonance frequency among the sound waves entering the resonance chamber from the through hole can be absorbed by the sound absorbing material. It can be surely reduced.

  According to invention of Claim 3, the said flame | frame acts as a wind direction board of the airflow which flowed into the inside of the said soundproof wall, and further swirls an airflow in the said soundproof wall, and an airflow is in the said soundproof wall. By lengthening the time spent in the sound, it is possible to make it easy to absorb sound using a large number of through holes formed in the sound barrier.

It is a partial exploded perspective view of the electric blower assembly which shows the embodiment of the present invention. It is a front view of a part of the electric blower assembly. It is a front view of the vacuum cleaner provided with the electric blower assembly. It is a sectional side view of the vacuum cleaner provided with the electric blower assembly. It is a partial expanded sectional view of the vacuum cleaner provided with the electric blower assembly. It is sectional drawing of an electric blower assembly as the same.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention. In the following description, the top and bottom in FIGS. 2 to 6 are defined as top and bottom, the right side in FIGS. 4 to 6 is the front, and the left side is the back. However, regarding FIG. 1, the lower left is lower and the upper right is upper.

  Reference numeral 1 denotes an electric blower assembly of the present invention. The electric blower assembly 1 includes an electric blower 1A. The electric blower 1 </ b> A includes a centrifugal fan 4 configured by a plurality of blades 2 and a shroud 3 formed integrally with the blades 2. The electric blower 1 </ b> A includes a fan case 6 that includes the centrifugal fan 4 and is provided with an air inlet 5 at the lower center. The fan case 6 includes a first fan cover 6 </ b> A that covers the lower side that is the upstream side of the centrifugal fan 4, and a second fan cover 6 </ b> B that covers the upper side that is the downstream side of the centrifugal fan 4. The second fan cover 6B is provided with guide vanes 7 that rectify the air blown from the centrifugal fan 4 and guide it upward, and the wind guided by the guide vanes 7 is discharged from the ventilation holes 7A. . A shaft hole 7B is provided at the center of the second fan cover 6B. Further, the second fan cover 6B includes an electric motor 8 having a rotating shaft 8A for rotating the centrifugal fan 4, and the rotating shaft 8A passes through the shaft hole 7B of the second fan cover 6B. The centrifugal fan 4 is connected. The electric motor 8 itself is also fixed to the second fan cover 6B by a screw (not shown). The centrifugal fan 4, the fan case 6, and the electric motor 8 constitute the electric blower 1A.

  The electric blower assembly 1 includes a soundproof cylinder 10 integrally formed with a cylindrical frame 9 containing the electric motor 8. As shown in FIG. 1, the frame 9 of the soundproof cylinder 10 is formed with an exhaust port 11 in which a part of the wall surface is notched. The exhaust port 11 is formed at the rear portion of the frame 9. Further, the frame 9 is formed with a flat portion 12 projecting outward at a lower portion thereof, and a first hanging portion 13 is formed on a lower surface side peripheral portion of the flat portion 12, and further outward from the first hanging portion 13. A step portion 14 is formed so as to protrude from the lower surface side peripheral portion of the step portion 14, and a second hanging portion 15 is formed downward, and the lower end of the second hanging portion 15 serves as an opening portion 15 </ b> A. In addition, the soundproof cylinder 10 is formed with a soundproof wall 16 standing on the upper surface side of the flat portion 12 so as to cover the side of the frame 9. An upper flange 17 is formed on the soundproof wall 16. A space 18 is provided between the soundproof wall 16 and the frame 9 for the flow of the air flow generated by the electric blower 1A.

  A plurality of first through holes 19 are formed between the upper flange 17 and the step portion 14 in the soundproof wall 16 formed so as to cover the side of the frame 9. A number of the first through holes 19 are formed at equal intervals in the height direction of the soundproof wall 16 and over the entire circumference. The first through hole 19 penetrates in a direction orthogonal to the rotation shaft 8A, and thereby, a space 18 provided between the soundproof wall 16 and the frame 9 and an outer side of the soundproof cylinder 10 to be described later. The resonance chamber 37 is in communication.

  The flat portion 12 that connects the soundproof wall 16 and the frame 9 is provided with a number of second through holes 20 that communicate with each other in the vertical direction at equal intervals. The second through-hole 20 penetrates in parallel with the axial direction of the rotary shaft 8A, and thereby the space on the opening 15A side and the space 18 are communicated.

  Furthermore, a large number of third through holes 21 are formed in the first hanging portion 13 in the circumferential direction. The third through hole 21 penetrates in a direction orthogonal to the rotation shaft 8A, that is, in parallel with the first through hole 19, so that the space on the opening 15A side and the outer side of the soundproof cylinder 10 are provided. A later-described resonance chamber 37 is communicated.

  A first sound absorbing material 22 made of a felt-like fiber material, urethane foam material or the like is attached to the outer peripheral surface of the soundproof wall 16 over the entire circumference, and the first through hole 19 and the third through hole are attached. 21 is provided so as to cover from the outside. Further, a second sound absorbing material 23 made of a urethane foam material or the like is provided along the inner peripheral surface of the frame 9, and the space 18 between the soundproof wall 16 and the frame 9 is also made of a urethane foam material or the like. A third sound absorbing material 24 is provided. In addition, although mentioned later for details, these sound-absorbing materials 22, 23, and 24 can absorb the sound wave which propagates from the through-holes 19, 20, and 21 drilled in each part, and can reduce a noise. In addition, since at least the third sound absorbing material 24 has air permeability, the air flow F generated by the electric blower 1A can flow from the inside to the outside of the third sound absorbing material 24 in the space 18. .

In addition, when the electric blower 1A is housed in the soundproof cylinder 10, the electric blower 1A is provided below the step portion 14 and inside the second hanging portion 15, and the upper and side portions of the second fan cover 6B. A first vibration isolation member 25 that covers the electric blower 1A is attached to the electric blower 1A. A second vibration isolation member 27 that covers the lower and side portions of the first fan cover 6A is mounted below the electric blower 1A. That is, the electric blower 1 </ b> A is accommodated in the soundproof cylinder 10 with the fan case 6 covered with the first vibration isolation member 25 and the second vibration isolation member 27. The first vibration isolation member 25 and the second vibration isolation member 27 are formed of an elastic member such as foam rubber. A communication hole 26 corresponding to and communicating with the air inlet 5 of the electric blower 1 </ b> A is formed at the center of the second vibration isolation member 27. At this time, the lower end of the first vibration isolation member 25 and the upper end of the second vibration isolation member 27 are in contact with each other, so that the fan case 6 covers the periphery of the fan case 6 from the lower part to the upper part with the vibration isolation members 25 and 27. Is called.
Then, the lower side of the second vibration isolation member 27 is covered with a lid 29, and the lid 29 is used to close the opening 15A of the soundproof cylinder 10, so that the electric blower 1A is accommodated in the soundproof cylinder 10, Can be fixed. The lid 29 is provided with a vent hole 28 corresponding to the intake port 5 and the communication hole 26.

  With such a configuration, the first vibration isolation member 25 and the second vibration isolation member 27 cover the periphery of the fan case 6 of the electric blower 1A. Therefore, the vibration of the electric motor 8 itself of the electric blower 1A and the centrifugal fan 4 The vibration due to the rotation can be suppressed and the vibration noise can be reduced. In addition, recesses are formed inside the first vibration isolation member 25 and the second vibration isolation member 27 corresponding to the protrusions formed on the outer case of the fan case 6, and these recesses and the fan By fitting the protrusions of the case 6, the electric blower 1 </ b> A is regulated so as not to move inside the soundproof cylinder 10, and the soundproof cylinder 10 and the electric blower 1 </ b> A are integrated.

  3 to 5 show a vertical vacuum cleaner 30 in which the electric blower 1A is built. The electric vacuum cleaner 30 includes, in addition to the electric blower 1A incorporated therein, a vacuum cleaner body 32 having a grip portion 31 at an upper portion thereof, a dust collection portion 33 that is detachably attached to the vacuum cleaner body 32, A suction nozzle 34.

  The electric blower 1 </ b> A is provided inside the casing 35 of the cleaner body 32, with the lid 29 facing downward above the dust collecting portion 33. The dust part 33 is communicated. The casing 35 is formed so that the inner wall thereof is in contact with the side end portions of the soundproof cylinder 10 and the lid 29, and fixes the soundproof cylinder 10 that houses the electric blower 1A. A partition wall 35 </ b> A is formed on the inner wall of the casing 35. The partition blocks the upper rear portion of the space 18.

For this reason, when the soundproof cylinder 10 containing the electric blower 1A is mounted in the casing 35, the soundproof wall 16, the stepped portion 14 and the upper flange 17, and the casing are provided outside the soundproof wall 16. A resonance chamber 37 is defined by an enclosure 36 which is a part of 35. The enclosure 36 refers to a portion of the casing 35 from the step 14 to the upper flange 17. The electric blower assembly 1 is constituted by the electric blower 1A, the soundproof wall 16 including the stepped portion 14 and the upper flange 17, the enclosure portion 36 of the casing 35, and the resonance chamber 37 defined by these. Composed.
When the electric vacuum cleaner 30 is energized and operated, a voltage is applied to the electric motor 8 of the electric blower 1A, and the centrifugal fan 4 fixed to the rotary shaft 8A of the electric motor 8 rotates at high speed. When the suction force is applied by the centrifugal fan 4, dust on the surface to be cleaned flows into the introduction part 38 from the suction nozzle 34 together with the air flow F (the arrow indicated by the solid line in FIGS. 5 and 6). Further, the air flow F rises up the introduction part 38 and swirls in the cyclone cylinder 39 of the dust collecting part 33, and coarse dust contained in the dust is centrifuged in the cyclone cylinder 39. The air flow F is provided with a large number of small holes on the outer peripheral surface and flows into the outer cylinder 40 having a downward taper shape. The filter member 41 mounted in the outer cylinder 40 causes the air flow F to flow into the outer cylinder 40. The remaining fine dust is filtered. The air flow F from which the dust has been removed by the dust collecting portion 33 passes through the vent hole 28 provided in the lid 29 and the communication hole 26 provided in the second vibration isolation member 27, so that It flows into the intake port 5. The air flow F flowing into the intake port 5 is given rotational kinetic energy by the blade 2 of the centrifugal fan 4 and discharged from the centrifugal fan 4 in the centrifugal direction, and this is provided in the second fan cover 6B. The air is rectified by the guide vanes 7 and flows into the soundproof cylinder 10 from the ventilation holes 7A. Here, when the air flow F is exhausted by the centrifugal fan 4, the air flow causes pulsation in the air flow and generates high-frequency sound having a pulsation frequency component and a harmonic component.

  As shown in FIG. 6, the air flow F to which kinetic energy is applied by the centrifugal fan 4 is rectified by the guide vanes 7 and further swung along the inner peripheral surface of the frame 9 from the ventilation port 7A. Then, after being discharged into the space 18 through the exhaust port 11 formed on the wall surface of the frame 9, the air is exhausted from the cleaner body 32 to the outside through the cleaner body 32. Further, a part of the air flow F is discharged to the space 18 through the second through hole 20 formed in the flat portion 12 and is discharged from the exhaust port 11 into the space 18. After joining with F, the air passes through the cleaner body 32 and is exhausted from the cleaner body 32 to the outside. These air flows F are discharged from the exhaust port 11 to the space 18 and swirl through the space 18 when the frame 9 provided in the soundproof cylinder 10 acts like a wind direction plate. As described above, the partition wall 35A of the casing 35 closes the upper rear portion of the space 18 of the soundproof cylinder 10, and the exhaust port 11 is formed at the rear portion of the frame 9, that is, below the partition wall 35A. Therefore, after the air flow F is discharged from the rear exhaust port 11 to the space 18, it cannot be discharged from the upper rear portion of the space 18. It is discharged from the upper front. Accordingly, the formation of the partition wall 35A facilitates the turning of the air flow F in the space 18.

  Consider a case where sound waves generated by the electric blower 1 </ b> A (that is, air dense waves) enter the resonance chamber 37 through the first through hole 19 and the third through hole 21. In this case, since the resonance chamber 37 is substantially sealed except for the first through hole 19 and the third through hole 21, a sound wave “tight” portion is formed in the first through hole 19 and the third through hole 21. When trying to enter, the pressure in the resonance chamber 37 is relatively slightly increased, so that air is pushed out. On the contrary, when the “coarse” portion of the sound wave is about to enter, the pressure in the resonance chamber 37 is relatively slightly lowered, so that air is drawn in. This phenomenon can be said to be vibration due to the resonance frequency determined by the diameters of the first through hole 19 and the third through hole 21 and the volume of the resonance chamber 37. This vibration resonates with a frequency component corresponding to the resonance frequency in the sound wave and works to cancel the sound wave vibration (in other words, the vibration energy of the resonance frequency in the sound wave is transferred to the air vibration in the resonance chamber 37. Therefore, by repeating this vibration, the resonance frequency component in the sound wave is canceled and the sound pressure level is lowered. The resonance frequency is preferably tuned so as to coincide with the highest sound pressure level in the sound wave generated by the electric blower 1A.

  Note that a sound wave having a frequency different from the resonance frequency is hardly absorbed by the resonance described above, and thus passes through the first through hole 19 and the third through hole 21, but this sound wave is absorbed by the first sound absorbing material 22. Is done. Sound waves are also absorbed by the second sound absorbing material 23 and the third sound absorbing material 24. In this way, the noise generated by the electric blower 1A is absorbed.

  Moreover, since the air flow F swirls in the space 18 as described above, it is possible to lengthen the time that the air flow F stays in the soundproof wall 16. For this reason, sound waves using air as a medium are also caused to flow in the air flow F swirling in the space 18. Accordingly, since the interaction between the sound wave and the first through hole 19 of the soundproof wall 16 is performed for a relatively long time, the noise generated by the electric blower 1A can be more effectively absorbed.

  As described above, in this embodiment, the electric fan 1A including the electric motor 8 having the rotating shaft 8A and the centrifugal fan 4 provided on the rotating shaft 8A of the electric motor 8 is provided around the electric fan 1A. In the electric blower assembly 1 provided with the soundproof wall 16, a number of first through holes 19 are formed in the soundproof wall 16, and an enclosure portion 36 that is a part of the casing 35 is provided outside the soundproof wall 16. In addition, since the resonance chamber 37 defined by the soundproof wall 16 and the enclosure 36 is provided, when sound waves are propagated from the first through hole 19 into the resonance chamber 37, the air in the resonance chamber 37 is Since it resonates with a frequency component corresponding to the resonance frequency in the sound wave and works to cancel the sound wave vibration, the resonance frequency component in the sound wave is canceled and noise transmitted to the outside can be reduced.

  Further, by providing the first sound absorbing material 22 in the resonance chamber 37, vibration energy of sound waves other than the resonance frequency among the sound waves entering the resonance chamber 37 from the first through hole 19 is converted into the first sound absorption material 22. Noise that is absorbed by the sound absorbing material 22 and propagates to the outside can be reliably reduced.

  Further, by providing the frame 9 with the exhaust port 11 formed inside the soundproof wall 16, the frame 9 acts as a wind direction plate for the air flow F flowing into the soundproof wall, and air The flow F is further swirled in the soundproof wall 16, and sound waves using air as a medium are swirled in the space 18, thereby using a large number of the first through holes 19 formed in the soundproof wall 16. Therefore, it is possible to easily absorb sound and to reliably reduce noise.

  In addition, this invention is not limited to a present Example, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above embodiment, the portion of the casing 35 from the upper flange 17 to the step portion 14 of the soundproof wall 16 that abuts on the casing 35 is the surrounding portion 36, but the upper flange or the step portion 14 is placed inside the casing 35. A corresponding rib portion may be formed. Further, an enclosure portion independent of the casing 35 may be provided outside the soundproof wall 16. In the present embodiment, the first sound absorbing material 22, the second sound absorbing material 23, the third sound absorbing material 24 and the three sound absorbing materials are provided in the soundproofing cylinder 10. However, even if only the first sound absorbing material 22 is used. I do not care. Further, no sound absorbing material may be used.

DESCRIPTION OF SYMBOLS 1 Electric blower assembly 1A Electric blower 4 Centrifugal fan 8 Electric motor 8A Rotating shaft 9 Frame 10 Soundproof cylinder 11 Exhaust port 14 Step part 16 Soundproof wall 17 Upper flange 19 First through-hole 20 Second through-hole 21 Third through-hole 22 First Sound absorbing material 36 Enclosure 37 Resonance chamber

Claims (3)

In the electric blower assembly comprising an electric motor having a rotating shaft, an electric blower provided with a fan provided on the rotating shaft of the electric motor, and a soundproof wall provided around the electric blower, the soundproof wall includes a number of An electric blower assembly, wherein a through hole is formed, an enclosure is provided outside the soundproof wall, and a resonance chamber defined by the soundproof wall and the enclosure is provided. The electric blower assembly according to claim 1, wherein a sound absorbing material is provided in the resonance chamber. The electric blower assembly according to claim 1, wherein a frame in which an exhaust port is formed is provided inside the soundproof wall.

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