WO2009130891A1 - Centrifugal fan and method of reducing noise of centrifugal fan - Google Patents

Centrifugal fan and method of reducing noise of centrifugal fan Download PDF

Info

Publication number
WO2009130891A1
WO2009130891A1 PCT/JP2009/001819 JP2009001819W WO2009130891A1 WO 2009130891 A1 WO2009130891 A1 WO 2009130891A1 JP 2009001819 W JP2009001819 W JP 2009001819W WO 2009130891 A1 WO2009130891 A1 WO 2009130891A1
Authority
WO
WIPO (PCT)
Prior art keywords
centrifugal blower
suction port
protrusions
outer shell
protrusion
Prior art date
Application number
PCT/JP2009/001819
Other languages
French (fr)
Japanese (ja)
Other versions
WO2009130891A8 (en
Inventor
ドンビン マ
森岡政光
白濱誠司
Original Assignee
広東松下環境系統有限公司
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 広東松下環境系統有限公司, パナソニック株式会社 filed Critical 広東松下環境系統有限公司
Priority to US12/920,163 priority Critical patent/US20110002775A1/en
Priority to CN2009801069514A priority patent/CN101965461A/en
Publication of WO2009130891A1 publication Critical patent/WO2009130891A1/en
Publication of WO2009130891A8 publication Critical patent/WO2009130891A8/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/663—Sound attenuation
    • F04D29/664—Sound attenuation by means of sound absorbing material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/663—Sound attenuation
    • F04D29/665—Sound attenuation by means of resonance chambers or interference
    • 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
    • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects

Definitions

  • the present invention relates to a centrifugal blower used for a ventilation blower and the like, and a noise reduction method for a centrifugal blower that reduces noise generated by the operation of the centrifugal blower.
  • this type of centrifugal blower is used for a centrifugal blower or the like, and is known to have an orifice on one surface of an outer shell that is different from a suction casing having a bell mouth-like suction port (for example, a patent) Reference 1).
  • the centrifugal blower 100 includes an outer shell 101 that is open on one surface, an impeller 103 that is rotatably supported by the top surface 102 in the outer shell 101, and an impeller 103 that is fixed to the top surface 102.
  • An electric motor 104 that rotates the motor, a scroll casing 105 that surrounds the impeller 103, and a suction casing 107 that has a suction port 106.
  • the centrifugal blower 100 includes an orifice 109 having a suction hole 108 that is equal to or smaller than the suction port 106 with a predetermined gap h from the suction casing 107.
  • the orifice 109 is provided with the lower end 110 of the suction casing 107 and the end 111 of the orifice 109 separated by a gap dimension i.
  • the resonance space 112 communicated with the suction port 106 through the inlet portion 115 between the lower end 110 of the suction casing 107 and the end portion 111 of the orifice 109 is defined by the outer shell 101, the scroll casing 105, and the orifice 109.
  • the centrifugal blower 100 includes a grill 113 disposed on one surface of the orifice 109 and a discharge port 114 provided on one side surface of the outer shell 101.
  • a relatively low frequency noise of approximately 1 kHz or less can be reduced by the resonance silence effect, but a relatively low frequency noise reduction effect of approximately 1 kHz or more such as noise caused by turbulent flow is low. . Therefore, there is a problem that the amount of noise reduction is small when high-frequency noise is dominant, such as when the amount of air blown by the centrifugal blower is large. Therefore, the centrifugal blower is required to enhance the noise reduction effect in the high frequency range and reduce noise in a wide frequency range from low frequency to high frequency.
  • the present invention solves such a conventional problem, and in a centrifugal blower, the noise reduction effect in the high frequency range can be enhanced, noise can be reduced in a wide frequency range from low frequency to high frequency, and noise can be reduced. It aims at providing the centrifugal blower which reduces.
  • the present invention is configured as follows.
  • the outer shell having the opening, the impeller supported rotatably in the outer shell, the electric motor that rotationally drives the impeller, the first suction port, and the blade It is arranged at the opening of the outer shell so as to have a gap between the casing disposed in the outer shell so as to surround the periphery of the vehicle and the first suction port of the casing, and the opening of the outer shell and the first of the casing A bell mouth-shaped orifice having a second suction port communicating with the suction port, and communicated with the first suction port through a gap between the first suction port and the second suction port.
  • a centrifugal blower in which a resonance space that resonates and muffles noise emitted from one suction port is defined with an orifice, a casing, and an outer wall as a defining wall, and a plurality of protrusions are provided on the defining wall of the resonance space.
  • each of the plurality of protrusions has an inclined surface that is inclined with respect to the defining wall surface of the resonance space at each of the formation positions.
  • the centrifugal blower according to the first aspect is provided, in which a slope of another projection adjacent to the projection is connected to each other, and a recess is formed between the projections by each slope.
  • centrifugal blower according to the second aspect, wherein an angle of a connection portion of each inclined surface in the recess is an acute angle.
  • the protruding portion provides the centrifugal blower according to the second aspect, which has a flat surface at the top.
  • the centrifugal blower according to the second aspect wherein the protrusion has a shape whose depth is long with respect to its height and width.
  • the plurality of protrusion groups in which the plurality of protrusions are arranged with the depth direction parallel to each other are arranged such that the depth directions of adjacent protrusion groups intersect each other.
  • the centrifugal blower according to the fifth aspect is provided.
  • a plurality of protrusion groups in which a plurality of protrusions are arranged in parallel in the depth direction are arranged so that each depth direction is different.
  • the plurality of recesses formed between the plurality of protrusions are formed so as to extend along the defining wall surface, and are at least in the radial direction, the circumferential direction, and the axial direction of the impeller.
  • the centrifugal blower according to the fifth aspect is provided in which the extending directions of the respective recesses are arranged differently with respect to one direction.
  • any of the first to eighth aspects has the same shape of the plurality of protrusions and the same shape of the plurality of recesses formed between the plurality of protrusions.
  • a centrifugal blower according to claim 1 is provided.
  • any one of the first to eighth aspects there are a plurality of types of protrusions and a plurality of types of recesses formed between the plurality of protrusions.
  • a centrifugal blower as described is provided.
  • the centrifugal blower according to any one of the first to eighth aspects, wherein a plurality of protrusions are provided on the orifice in the resonance space.
  • the plurality of protrusions are formed integrally with an orifice, a casing, or a demarcating wall of the outer shell, and the centrifuge according to any one of the first to eighth aspects.
  • the centrifugal blower according to any one of the first to eighth aspects, wherein the protrusion is detachably installed on the defining wall.
  • the centrifugal blower according to the thirteenth aspect, wherein the protrusion is formed of a sound absorbing material.
  • any one of the first to eighth aspects is provided, wherein the protrusion is formed with a hollow inside, and a hole communicating the cavity and the resonance space is formed in the protrusion.
  • a centrifugal blower according to claim 1 is provided.
  • the outer shell having the opening, the impeller rotatably supported in the outer shell, the first suction port, and surrounding the periphery of the impeller Is disposed in the opening of the outer shell so as to have a gap between the casing disposed in the casing and the first suction port of the casing, and the second opening for communicating the opening of the outer shell and the first suction port of the casing.
  • a centrifugal blower including a bell mouth-shaped orifice having a suction port
  • the first suction port is communicated with the first suction port through a gap between the first suction port and the second suction port to define the orifice, the casing, and the outer shell.
  • a sound wave of noise generated in the casing as the impeller is driven to rotate is incident through a gap between the first suction port and the second suction port into the resonance space defined as a wall, Incident on
  • the level of the sound wave of the sound as well as to reduce the air column resonance, thereby reducing the level of acoustic noise by diffused reflection of the acoustic waves of noise at the resonant space, provides a noise reduction method of the centrifugal blower.
  • a resonance space communicating with the first suction port of the casing is provided, and a configuration in which a plurality of protrusions are provided in the resonance space is employed.
  • noise generated by the operation of the centrifugal blower is incident on the resonance space communicated with the first suction port of the casing of the centrifugal blower to enter the resonance space.
  • the sound wave level of the incident noise can be reduced by air column resonance.
  • the sound wave level can be reduced by irregularly reflecting the sound wave of noise in the resonance space. Therefore, the two effects of air column resonance and irregular reflection can enhance the noise reduction effect in the high frequency range of noise associated with the operation of the centrifugal blower, and reduce the noise in a wide frequency range from low frequency to high frequency.
  • FIG. 2A It is a model perspective view which shows the shape of the permite
  • FIG. 1A A schematic cross-sectional view of the centrifugal blower 1 according to the first embodiment of the present invention is shown in FIG. 1A, and a partially enlarged view of a portion X in FIG. 1A is shown in FIG. 1B.
  • a centrifugal blower 1 used as a ceiling-embedded ventilation fan has a multi-blade impeller that can rotate around a rotating shaft 4 in an outer shell 3 having an opening 2 on a lower surface.
  • a casing 10 having a bell mouth-like suction port 7 (first suction port) in the opening and a discharge port 9 in the side wall 8. ing.
  • the discharge port 9 of the casing 10 communicates with the discharge adapter 12 through a discharge opening 11 provided on one side surface of the outer shell 3.
  • a flange portion 13 is provided on the outer periphery of the lower surface of the outer shell 3, and the outer shell 3 is fixed to the ceiling material 15 with screws or the like through a hole 14 provided in the flange portion 13, and a duct 16 disposed on the ceiling and communicating with the outside is discharged. It is joined to the discharge port 9 via the adapter 12.
  • an orifice 18 that is concentric with the suction port 7 of the casing 10 and includes a bell mouth-shaped suction port 17 (second suction port) is disposed in the opening 2 of the outer shell 3. That is, the opening 2 of the outer shell 3 communicates with the suction port 7 of the casing 10 through the suction port 17 of the orifice 18. 1A and 1B, the end portion 20 of the orifice 18 is located at a gap dimension j from the lower surface of the suction port 7 of the casing 10, and the gap portion is provided between the orifice 18 and the casing 10. A (gap) 21 is formed.
  • a resonance space 19 defined by being surrounded by the orifice 18, the casing 10, and the outer shell 3 is defined.
  • the resonance space 19 communicates with the suction port 7 of the casing 10 through a gap 21 between the orifice 18 and the casing 10.
  • each protrusion 22 and the orifice 18 are one part integrally molded.
  • the protrusion 22 has a shape that is longer in the depth direction (one direction in the plane) than the width in plan view.
  • the protrusions 22 having such a long shape in the depth direction are arranged on the orifice 18 as a plurality of protrusion groups (protrusion part groups) 30 arranged in a set of three with the depth direction being parallel. As shown in FIG. 2A, the adjacent protrusion groups 30 are arranged so that the depth directions thereof are substantially orthogonal to each other.
  • the protrusion 22 has a shape in which the protrusion depth L (the length in the Y direction in the drawing) is longer than the protrusion height ho (the height in the Z direction in the drawing). Further, the protrusion 22 has a trapezoidal cross-sectional shape (XZ cross-sectional shape) perpendicular to the depth direction (Y direction).
  • the top of the projection 22 is a flat surface 31, and the top flat surface 31 having a width a is spread on both sides by a width c as it goes downward, on both side surfaces (both side surfaces in the X direction) of the projection 22.
  • An inclined surface 32 inclined with respect to the Z direction is formed.
  • a recess 23 having a substantially V-shaped cross section is formed by two inclined surfaces 32 between two protrusions 22 arranged in parallel in the depth direction.
  • the opening width of the upper portion of the recess 23 is b, and gradually decreases toward the lower side in the Z direction, and the two inclined surfaces 32 intersect at the recess angle ⁇ .
  • the depression angle ⁇ is an acute angle.
  • the centrifugal blower 1 having such a configuration, an operation of reducing noise generated by the rotational drive of the impeller 5 by the resonance space 19 and the plurality of protrusions 22 provided in the resonance space 19 will be described.
  • the intake air passes from the main body opening 2 through the suction port 17 of the orifice 18, enters the impeller 5 through the suction port 7 of the casing 10, and is boosted by the impeller 5. , Passes through the inside of the casing 10 and is discharged from the discharge adapter 12 to the duct 16 and discharged to the outdoors.
  • each recess 23 has a substantially V-shaped cross section, and the width of the recess 23 is set to be narrow.
  • the sound wave incident on the depression 23 is reflected more times, causing irregular reflection, and the sound reduction effect is strong and noise can be reduced.
  • the relationship of ho ⁇ b is preferable with respect to the protrusion height ho and the recess opening width b.
  • the protrusion 22 has a trapezoidal cross-sectional shape perpendicular to the depth direction of the protrusion 22, and the shape of the recess 23 formed by the protrusion 22 is gradually narrowed toward the lower side. Therefore, the sound wave incident on the depression 23 is diffusely reflected, and the time interval at which the reflection occurs becomes shorter as the sound wave travels to the lower side of the depression 23. Thereby, since the frequency
  • the trapezoidal shape of the cross section of the protrusion 22 preferably has a relationship of ho ⁇ c with respect to the protrusion height ho and the width c of the inclined surface 32.
  • the same effect can be expected when the cross-sectional shape of the protrusion 22 is triangular.
  • the volume of the recess 23 is adjusted by adjusting the width a of the top flat surface 31 of the protrusion 22 while keeping the angle of the inclined surface 32 at an optimum angle by making the cross-sectional shape of the protrusion 22 trapezoidal. can do.
  • the same effect can be expected when the inclined surface of the protrusion 22 forming the recess 23 is not only formed as a flat surface but also when the inclined surface is a curved surface.
  • the dent angle ⁇ of the dent 23 is an acute angle, irregular reflection is likely to occur even for a sound wave having a shallow incident angle with respect to the dent 23, so that a sound reduction effect can be easily obtained and noise can be effectively obtained. Can be reduced.
  • the protrusion 22 has a shape that is long in depth with respect to the height and width of the protrusion 22, the recess 23 formed by the protrusion 22 has a slit shape. Therefore, irregular reflection can be generated even for a sound wave having a shallow (small) incident angle with respect to the depth direction of the protrusion 23 and the slit direction (that is, the Y direction (see FIG. 3)). As a result, a sound reduction effect can be easily obtained, and noise can be reduced.
  • L 1.5ho or L> 1.5a.
  • each protrusion 22 is the same and the shape of the recess 23 formed by each protrusion 22 is the same, the frequency of the sound wave reduced by the irregular reflection at the recess 23 is Since it depends on the shape, the sound reduction effect works strongly for a specific frequency, and noise can be reduced.
  • the sound wave entering the resonance space 19 from the gap 21 tends to be diffracted toward the orifice 18 in the resonance space 19 by the end 20 of the orifice 18 (see FIGS. 1A and 1B). Therefore, the possibility that the sound wave collides with the orifice 18 is increased. Therefore, by forming the plurality of protrusions 22 and the depressions 23 on the orifice 18, sound waves can be effectively incident on the depressions 23, and noise can be reduced by the sound reducing action of the depressions 23.
  • the protrusion 22 and the orifice 18 are formed as a single component, the plurality of protrusions 22 and the recesses 23 are formed in the resonance space 19 without increasing the number of components. Can be provided.
  • FIG. 2B by making the cross-sectional shape of the orifice 18 a shape that can be manufactured by a die with one direction removed, the manufacturing is easy and the manufacturing cost can be reduced.
  • the slit-like depressions 23 arranged in parallel by one projection group 30 are maximized.
  • Four can be formed. There is a characteristic that the incidence rate of irregular reflection by the depression 23 becomes higher as the sound wave in a direction near to the longitudinal direction of the slit-like depression 23 becomes higher, and for example, by combining four or more protrusions 22, the characteristic is further improved. Become stronger.
  • the projection groups 30 that form a set of four depressions 23 in the orifice 18 are arranged alternately vertically and horizontally. By doing so, it is possible to compensate for the low occurrence rate between adjacent sets. Therefore, irregular reflection by the depression 23 can be effectively generated, and a sound reduction effect can be obtained.
  • the inner dimension of the outer shell 3 is 264 mm square, the height is 195 mm, the diameter of the impeller 5 is 183.5 mm, the inner diameter Di of the suction port 7 is 152 mm, and the suction port 17
  • FIG. 4 shows a graph of noise characteristic values of the centrifugal blower of the comparative example in which 22 is not provided (the other conditions are the same as those of the example).
  • the solid line is the noise characteristic value of the centrifugal fan of the example having the protrusions 22 and the depressions 23, and the dotted line is the noise characteristic value of the centrifugal fan of the comparative example having no protrusions and depressions.
  • the noise characteristics of the embodiment are reduced in sound pressure levels at various frequencies, particularly in the relatively high frequency ranges of 1 kHz to 1.4 kHz and 2.6 kHz to 3.4 kHz. It can be seen that the sound is more prominent than the comparative example. Therefore, it has been confirmed that by adopting the configuration of the centrifugal blower of the first embodiment, a noise reduction effect of 1 dB can be obtained in overall.
  • the depth direction of the protrusion 22 of each protrusion group 30 is arranged in a direction parallel to the radial direction of the impeller 5 and in a direction inclined from the orthogonal direction.
  • the protrusion group 30 can also be arranged. Even in such a configuration, the same effect as the above-described configuration can be expected.
  • An arbitrary angle can be adopted as the inclination angle in the inclined direction.
  • the sound reduction effect by air column resonance and the sound reduction effect by diffuse reflection are used together to enhance the sound reduction effect in the high frequency range and reduce the noise in a wide frequency range from low frequency to high frequency.
  • a centrifugal blower can be obtained.
  • FIG. 7A shows a schematic perspective view of the orifice 18 included in the centrifugal blower of the second embodiment
  • FIG. 7B shows a cross-sectional view taken along the line BB in the orifice 18 of FIG. 7A.
  • a plurality of protrusions 22 are provided discontinuously on the inner side of the resonance space 19 of the orifice 18, that is, the side surfaces of the protrusions 22 are not directly connected to the side surfaces of the adjacent protrusions 22.
  • a recess 23 formed by a side surface and a bottom surface of each adjacent protrusion 22 is provided between the protrusions 22.
  • the protrusion 22 and the orifice 18 are formed as a single molded part.
  • the individual protrusions 22 have different shapes, and the protrusions 22 having a plurality of types of shapes are provided. For this reason, there are a plurality of types of shapes of the recesses 23 formed by the protrusions 22.
  • the plurality of protrusions 22 are discontinuously provided at intervals without directly connecting the respective side surfaces.
  • the recesses 23 are arranged at arbitrary intervals in the radial direction of the impeller 5.
  • each hollow 23 is arrange
  • the sound wave of the noise that has entered from the gap portion 21 has various directions due to diffraction and reflection inside the resonance space 19.
  • the respective recesses 23 are arranged with the slit-like longitudinal direction as various directions, a sound reduction effect can be obtained even for sound waves in various directions, and noise can be reduced. Can do.
  • the frequency of the sound wave reduced by the irregular reflection at the depression 23 depends on the shape of the depression 23, there are a plurality of types of the projections 22, and there are a plurality of types of the depressions 23 formed by the projections 22.
  • Configuration is adopted. With such a configuration, a sound reduction effect can be obtained at various frequencies as compared with the configuration of the first embodiment, and noise can be reduced in a wider frequency range.
  • each protrusion 22 and the hollow 23 are arranged so that the longitudinal direction is different from at least one of the radial direction, the circumferential direction, and the axial direction of the impeller 5, various directions can be provided. A sound reduction effect for sound waves can be obtained.
  • the sound reduction effect by air column resonance and the sound reduction effect by diffuse reflection are used together to enhance the sound reduction effect in the high frequency range and reduce noise in a wide frequency range from low frequency to high frequency.
  • a centrifugal blower that can be obtained is obtained.
  • FIG. 8 shows a schematic perspective view of the orifice 18 included in the centrifugal blower of the third embodiment.
  • the projections 22 having the same shape are formed as a set of projection groups 30 in the same manner as the arrangement of the projections 22 of the first embodiment shown in FIG. 2A.
  • the plurality of protrusion groups 30 are alternately arranged in the vertical and horizontal directions.
  • the configuration in which the plurality of projection groups 30 are formed integrally with the orifice 18 is employed.
  • the unit 24 to which the projection group 30 can be attached and detached is provided. In the point comprised as follows, the structure different from the said 1st Embodiment is employ
  • the unit 24 (corresponding to the protrusion group 30) includes three protrusions 22 arranged in parallel in the depth direction, and a slit-like depression 23 formed by these protrusions 22 is parallel to the depth direction. Two are provided. On the inner side of the resonance space 19 of the orifice 18, a plurality of units 24 are arbitrarily arranged vertically and horizontally so that the depth directions of the adjacent units 24 intersect each other. Each unit 24 is fixed to the orifice 18 by a fixing means such as a screw, so that it can be detached from the orifice 18.
  • each unit 24 can be changed into various forms, and various arrangements of the recesses 23 can be created with one type of unit 24. Further, since the unit 24 is detachable, the frequency at which the sound can be reduced can be adjusted by changing the arrangement of the recesses 23.
  • the unit 24 as a sound absorbing material such as glass wool, the gradual decrease of energy due to irregular reflection at the recess 23 becomes stronger, so that the sound reduction effect works strongly and noise can be reduced.
  • the sound reduction effect by air column resonance and the sound reduction effect by diffuse reflection are used together to enhance the sound reduction effect in the high frequency range, and reduce the noise in a wide frequency range from low frequency to high frequency.
  • a centrifugal blower in which the frequency of the noise to be reduced can be adjusted.
  • FIGS. 9A and 9B are schematic cross-sectional views showing the structures of the protrusions 22 and the recesses 23 provided in the centrifugal blower of the fourth embodiment.
  • the protrusion 22 of the fourth embodiment has a plate thickness of 1 mm, for example, and has a hollow 25 inside thereof, and further has a hole 27 of ⁇ 1.5 mm on the protrusion tip surface 26, for example. .
  • the protrusion 22 forms a Helmholtz resonance structure in which the cavity 25 is a volume part and the hole 27 is a throat part.
  • FIG. 9B such a structure of the projection 22 is formed by forming the orifice 18 with a thin plate to form the upper surface of each projection 22 and attaching a plate part 28 from the lower side of the orifice 18 in the figure.
  • the cavity 25 can be easily formed inside each projection 22.
  • the inside is a cavity 25 and a hole 27 is formed.
  • centrifugal blower capable of enhancing the noise reduction effect in the high frequency range and reducing noise in a wide frequency range from low frequency to high frequency.
  • the present invention provides a centrifugal blower that enhances a sound reduction effect in a high frequency range, can reduce noise in a wide frequency range from low frequency to high frequency, and reduces noise. Is available.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

A centrifugal fan is, within an outer shell, provided with an electric motor to which an impeller is connected, a casing for surrounding the impeller and having formed in one face thereof a bell-mouth-shaped suction opening, a bell-mouth-shaped orifice concentric with the suction opening and provided with a suction opening having a diameter equivalent to that of the suction opening, projections arranged in a resonance space surrounded by the orifice, the casing, and the outer shell, and recesses formed between the projections. The construction reduces noise of a wide frequency range produced by the centrifugal fan.

Description

遠心送風機および遠心送風機の騒音低減方法Centrifugal blower and noise reduction method for centrifugal blower
　本発明は、換気送風機器等に使用される遠心送風機、および遠心送風機の運転により生じる騒音を低減する遠心送風機の騒音低減方法に関する。 The present invention relates to a centrifugal blower used for a ventilation blower and the like, and a noise reduction method for a centrifugal blower that reduces noise generated by the operation of the centrifugal blower.
　従来、この種の遠心送風機は、遠心送風機などに用いられ、ベルマウス状の吸込み口を有する吸込ケーシングとは別のオリフィスを外郭の一面の開口に備えたものが知られている（例えば、特許文献１参照）。 Conventionally, this type of centrifugal blower is used for a centrifugal blower or the like, and is known to have an orifice on one surface of an outer shell that is different from a suction casing having a bell mouth-like suction port (for example, a patent) Reference 1).
　以下、この従来の遠心送風機１００について図１０を参照しながら説明する。 Hereinafter, the conventional centrifugal blower 100 will be described with reference to FIG.
　図１０に示すように、遠心送風機１００は、一面を開口した外郭１０１と、この外郭１０１内の天面１０２に回転可能に支持された羽根車１０３と、天面１０２に固定され、羽根車１０３を回転駆動する電動機１０４と、羽根車１０３の周囲を取り囲むスクロールケーシング１０５と、吸込み口１０６を有する吸込ケーシング１０７とを備えている。さらに、遠心送風機１００は、吸込ケーシング１０７と所定の間隙ｈを隔て吸込み口１０６より同等あるいは小さな吸込孔１０８を有するオリフィス１０９を備えている。オリフィス１０９は、吸込ケーシング１０７の下端１１０とオリフィス１０９の端部１１１とを間隙寸法ｉを隔てて設けられる。これにより、吸込ケーシング１０７の下端１１０とオリフィス１０９の端部１１１との間の入口部１１５を通じて吸込み口１０６と連通された共鳴空間１１２が、外郭１０１、スクロールケーシング１０５、およびオリフィス１０９により画定されている。また、遠心送風機１００は、このオリフィス１０９の一面に配置されたグリル１１３と、外郭１０１の一側面に設けた吐出口１１４とを備えている。 As shown in FIG. 10, the centrifugal blower 100 includes an outer shell 101 that is open on one surface, an impeller 103 that is rotatably supported by the top surface 102 in the outer shell 101, and an impeller 103 that is fixed to the top surface 102. An electric motor 104 that rotates the motor, a scroll casing 105 that surrounds the impeller 103, and a suction casing 107 that has a suction port 106. Furthermore, the centrifugal blower 100 includes an orifice 109 having a suction hole 108 that is equal to or smaller than the suction port 106 with a predetermined gap h from the suction casing 107. The orifice 109 is provided with the lower end 110 of the suction casing 107 and the end 111 of the orifice 109 separated by a gap dimension i. Thereby, the resonance space 112 communicated with the suction port 106 through the inlet portion 115 between the lower end 110 of the suction casing 107 and the end portion 111 of the orifice 109 is defined by the outer shell 101, the scroll casing 105, and the orifice 109. Yes. The centrifugal blower 100 includes a grill 113 disposed on one surface of the orifice 109 and a discharge port 114 provided on one side surface of the outer shell 101.
　このような従来の遠心送風機１００の構成において、羽根車１０３が回転すると、吸込空気はグリル１１３からオリフィス１０９の吸込孔１０８を通り、吸込ケーシング１０７の吸込み口１０６より羽根車１０３に入り羽根車１０３により昇圧され、スクロールケーシング１０５の内部を通り吐出口１１３より吐出される。このとき、羽根車１０３で昇圧される際に発生する回転騒音や、スクロールケーシング１０５を通る際に発生する渦による乱流騒音や、スクロールケーシング１０５内で発生した騒音の音波が吸込み口１０６から放射され、その一部は間隙寸法ｉの入口部１１５から共鳴空間１１２に入射する。入射した騒音の音波のうち、共鳴空間１１２の容積や形状によって特定される周波数の騒音の音波は、共鳴空間１１２内で気柱共鳴がおき、音波レベルが低減されて共鳴消音される。 In such a configuration of the conventional centrifugal blower 100, when the impeller 103 rotates, the intake air passes from the grill 113 through the suction hole 108 of the orifice 109, enters the impeller 103 through the suction port 106 of the suction casing 107, and the impeller 103. And is discharged from the discharge port 113 through the inside of the scroll casing 105. At this time, rotation noise generated when the pressure is increased by the impeller 103, turbulent noise due to vortex generated when passing through the scroll casing 105, and sound waves of noise generated in the scroll casing 105 are radiated from the suction port 106. A part of the light enters the resonance space 112 from the inlet 115 having the gap size i. Among the incident noise sound waves, noise sound waves of a frequency specified by the volume and shape of the resonance space 112 undergo air column resonance in the resonance space 112, and the sound wave level is reduced and resonance is silenced.
日本国特許第３２７９８３４号公報Japanese Patent No. 3279834
　このような従来の遠心送風機では、共鳴消音効果により概ね１ｋＨｚ以下の比較的低周波の騒音を減音できるが、乱流起因の騒音など概ね１ｋＨｚ以上の比較的高周波の騒音の減音効果が低い。そのため、遠心送風機の送風量が多い場合など高周波の騒音が主体的な場合に騒音の低減量が小さいという課題がある。したがって、遠心送風機においては、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することが要求されている。 In such a conventional centrifugal blower, a relatively low frequency noise of approximately 1 kHz or less can be reduced by the resonance silence effect, but a relatively low frequency noise reduction effect of approximately 1 kHz or more such as noise caused by turbulent flow is low. . Therefore, there is a problem that the amount of noise reduction is small when high-frequency noise is dominant, such as when the amount of air blown by the centrifugal blower is large. Therefore, the centrifugal blower is required to enhance the noise reduction effect in the high frequency range and reduce noise in a wide frequency range from low frequency to high frequency.
　本発明は、このような従来の課題を解決するものであり、遠心送風機において、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができ、騒音を低減する遠心送風機を提供することを目的としている。 The present invention solves such a conventional problem, and in a centrifugal blower, the noise reduction effect in the high frequency range can be enhanced, noise can be reduced in a wide frequency range from low frequency to high frequency, and noise can be reduced. It aims at providing the centrifugal blower which reduces.
　上記目的を達成するために、本発明は以下のように構成する。 In order to achieve the above object, the present invention is configured as follows.
　本発明の第１態様によれば、開口部を備える外郭と、外郭内にて回転可能に支持された羽根車と、羽根車を回転駆動する電動機と、第１の吸込み口を有し、羽根車の周囲を囲むように外郭内に配置されたケーシングと、ケーシングの第１の吸込み口との間に隙間を有するように外郭の開口部に配置され、外郭の開口部とケーシングの第１の吸込み口とを連通させる第２の吸込み口を有するベルマウス状のオリフィスとを備え、第１の吸込み口と第２の吸込み口との間の隙間を通じて第１の吸込み口と連通されて、第１の吸込み口から放出される騒音を共鳴消音する共鳴空間が、オリフィス、ケーシング、および外郭を画定壁として画定され、共鳴空間の画定壁に複数の突起部が設けられている、遠心送風機を提供する。 According to the first aspect of the present invention, the outer shell having the opening, the impeller supported rotatably in the outer shell, the electric motor that rotationally drives the impeller, the first suction port, and the blade It is arranged at the opening of the outer shell so as to have a gap between the casing disposed in the outer shell so as to surround the periphery of the vehicle and the first suction port of the casing, and the opening of the outer shell and the first of the casing A bell mouth-shaped orifice having a second suction port communicating with the suction port, and communicated with the first suction port through a gap between the first suction port and the second suction port. Provided is a centrifugal blower in which a resonance space that resonates and muffles noise emitted from one suction port is defined with an orifice, a casing, and an outer wall as a defining wall, and a plurality of protrusions are provided on the defining wall of the resonance space. To do.
　本発明の第２態様によれば、複数の突起部は、各々の形成位置において共鳴空間の画定壁面に対して傾斜された傾斜面を有し、１つの突起部の傾斜面と、この１つの突起部に隣接する別の１つの突起部の傾斜面とが互いに接続されて、それぞれの傾斜面により両突起部間に凹部が形成されている、第１態様に記載の遠心送風機を提供する。 According to the second aspect of the present invention, each of the plurality of protrusions has an inclined surface that is inclined with respect to the defining wall surface of the resonance space at each of the formation positions. The centrifugal blower according to the first aspect is provided, in which a slope of another projection adjacent to the projection is connected to each other, and a recess is formed between the projections by each slope.
　本発明の第３態様によれば、凹部におけるそれぞれの傾斜面の接続部分の角度が鋭角である、第２態様に記載の遠心送風機を提供する。 According to the third aspect of the present invention, there is provided the centrifugal blower according to the second aspect, wherein an angle of a connection portion of each inclined surface in the recess is an acute angle.
　本発明の第４態様によれば、突起部は、その頂部に平坦面を有する、第２態様に記載の遠心送風機を提供する。 According to the fourth aspect of the present invention, the protruding portion provides the centrifugal blower according to the second aspect, which has a flat surface at the top.
　本発明の第５態様によれば、突起部は、その高さおよび幅に対してその奥行きが長い形状を有する、第２態様に記載の遠心送風機を提供する。 According to the fifth aspect of the present invention, there is provided the centrifugal blower according to the second aspect, wherein the protrusion has a shape whose depth is long with respect to its height and width.
　本発明の第６態様によれば、その奥行き方向を平行にして複数の突起部が配列された複数の突起部群が、隣接する突起部群同士の奥行き方向が互いに交差するように配置されている、第５態様に記載の遠心送風機を提供する。 According to the sixth aspect of the present invention, the plurality of protrusion groups in which the plurality of protrusions are arranged with the depth direction parallel to each other are arranged such that the depth directions of adjacent protrusion groups intersect each other. The centrifugal blower according to the fifth aspect is provided.
　本発明の第７態様によれば、その奥行き方向を平行にして複数の突起部が配列された複数の突起部群が、各々の奥行き方向が異なるように配置されている、第５態様に記載の遠心送風機を提供する。 According to a seventh aspect of the present invention, in the fifth aspect, a plurality of protrusion groups in which a plurality of protrusions are arranged in parallel in the depth direction are arranged so that each depth direction is different. Provide centrifugal blower.
　本発明の第８態様によれば、複数の突起部の間に形成される複数の凹部が、画定壁面沿いに延在するように形成され、羽根車の径方向、周方向および軸方向の少なくとも１つの方向に対して、それぞれの凹部の延在方向が異なるように配列されている、第５態様に記載の遠心送風機を提供する。 According to the eighth aspect of the present invention, the plurality of recesses formed between the plurality of protrusions are formed so as to extend along the defining wall surface, and are at least in the radial direction, the circumferential direction, and the axial direction of the impeller. The centrifugal blower according to the fifth aspect is provided in which the extending directions of the respective recesses are arranged differently with respect to one direction.
　本発明の第９態様によれば、複数の突起部の形状が同じであり、複数の突起部の間に形成される複数の凹部の形状が同じである、第１態様から第８態様のいずれか１つに記載の遠心送風機を提供する。 According to the ninth aspect of the present invention, any of the first to eighth aspects has the same shape of the plurality of protrusions and the same shape of the plurality of recesses formed between the plurality of protrusions. A centrifugal blower according to claim 1 is provided.
　本発明の第１０態様によれば、突起部の形状が複数種類あり、複数の突起部の間に形成される凹部の形状が複数種類ある、第１態様から第８態様のいずれか１つに記載の遠心送風機を提供する。 According to the tenth aspect of the present invention, in any one of the first to eighth aspects, there are a plurality of types of protrusions and a plurality of types of recesses formed between the plurality of protrusions. A centrifugal blower as described is provided.
　本発明の第１１態様によれば、共鳴空間内において、オリフィス上に複数の突起部が設けられている、第１態様から第８態様のいずれか１つに記載の遠心送風機を提供する。 According to the eleventh aspect of the present invention, there is provided the centrifugal blower according to any one of the first to eighth aspects, wherein a plurality of protrusions are provided on the orifice in the resonance space.
　本発明の第１２態様によれば、複数の突起部は、オリフィス、ケーシング、または外郭の画定壁と一体的に形成されている、第１態様から第８態様のいずれか１つに記載の遠心送風機を提供する。 According to a twelfth aspect of the present invention, the plurality of protrusions are formed integrally with an orifice, a casing, or a demarcating wall of the outer shell, and the centrifuge according to any one of the first to eighth aspects. Provide a blower.
　本発明の第１３態様によれば、突起部は、画定壁に着脱可能に設置されている、第１態様から第８態様のいずれか１つに記載の遠心送風機を提供する。 According to the thirteenth aspect of the present invention, there is provided the centrifugal blower according to any one of the first to eighth aspects, wherein the protrusion is detachably installed on the defining wall.
　本発明の第１４態様によれば、突起部が、吸音材にて形成されている、第１３態様に記載の遠心送風機を提供する。 According to the fourteenth aspect of the present invention, there is provided the centrifugal blower according to the thirteenth aspect, wherein the protrusion is formed of a sound absorbing material.
　本発明の第１５態様によれば、突起部はその内部を空洞として形成され、この空洞と共鳴空間とを連通する孔部が突起部に形成されている、第１態様から第８態様のいずれか１つに記載の遠心送風機を提供する。 According to the fifteenth aspect of the present invention, any one of the first to eighth aspects is provided, wherein the protrusion is formed with a hollow inside, and a hole communicating the cavity and the resonance space is formed in the protrusion. A centrifugal blower according to claim 1 is provided.
　本発明の第１６態様によれば、開口部を備える外郭と、外郭内にて回転可能に支持された羽根車と、第１の吸込み口を有し、羽根車の周囲を囲むように外郭内に配置されたケーシングと、ケーシングの第１の吸込み口との間に隙間を有するように外郭の開口部に配置され、外郭の開口部とケーシングの第１の吸込み口とを連通させる第２の吸込み口を有するベルマウス状のオリフィスとを備える遠心送風機において、第１の吸込み口と第２の吸込み口との間の隙間を通じて第１の吸込み口と連通され、オリフィス、ケーシング、および外郭を画定壁として画定される共鳴空間内に、羽根車の回転駆動に伴ってケーシングにて発生した騒音の音波を第１の吸込み口と第２の吸込み口との間の隙間を通じて入射させ、共鳴空間内にて入射された騒音の音波のレベルを気柱共鳴により低減させるとともに、共鳴空間内にて騒音の音波を乱反射させることにより騒音の音波のレベルを低減させる、遠心送風機の騒音低減方法を提供する。 According to the sixteenth aspect of the present invention, the outer shell having the opening, the impeller rotatably supported in the outer shell, the first suction port, and surrounding the periphery of the impeller Is disposed in the opening of the outer shell so as to have a gap between the casing disposed in the casing and the first suction port of the casing, and the second opening for communicating the opening of the outer shell and the first suction port of the casing. In a centrifugal blower including a bell mouth-shaped orifice having a suction port, the first suction port is communicated with the first suction port through a gap between the first suction port and the second suction port to define the orifice, the casing, and the outer shell. A sound wave of noise generated in the casing as the impeller is driven to rotate is incident through a gap between the first suction port and the second suction port into the resonance space defined as a wall, Incident on The level of the sound wave of the sound as well as to reduce the air column resonance, thereby reducing the level of acoustic noise by diffused reflection of the acoustic waves of noise at the resonant space, provides a noise reduction method of the centrifugal blower.
　本発明の遠心送風機では、ケーシングの第１の吸込み口と連通された共鳴空間が備えられ、この共鳴空間内に複数の突起部を設けた構成が採用されている。このような構成が採用されていることにより、共鳴空間内に入射した騒音の音波に対して、気柱共鳴により音波レベルを低減させることができるとともに、複数の突起部により乱反射を生じさせて音波レベルを低減させることができる。したがって、気柱共鳴と乱反射との２つの作用により、遠心送風機の運転に伴って生じた騒音の高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができる。 In the centrifugal blower of the present invention, a resonance space communicating with the first suction port of the casing is provided, and a configuration in which a plurality of protrusions are provided in the resonance space is employed. By adopting such a configuration, it is possible to reduce the sound wave level due to air column resonance with respect to the sound wave of the noise that has entered the resonance space, and the sound wave is generated by irregular reflection by a plurality of protrusions. The level can be reduced. Therefore, the two effects of air column resonance and diffuse reflection can enhance the noise reduction effect in the high frequency range of noise generated with the operation of the centrifugal blower, and reduce the noise in a wide frequency range from low frequency to high frequency. it can.
　また、本発明の遠心送風機の騒音低減方法によれば、遠心送風機のケーシングの第１の吸込み口と連通された共鳴空間に、遠心送風機の運転により生じた騒音を入射させて、共鳴空間内にて入射された騒音の音波レベルを気柱共鳴により低減させることができる。それとともに、共鳴空間内にて騒音の音波を乱反射させることにより音波レベル低減させることができる。したがって、気柱共鳴と乱反射との２つの作用により、遠心送風機の運転に伴う騒音の高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができる。 Further, according to the noise reduction method for a centrifugal blower of the present invention, noise generated by the operation of the centrifugal blower is incident on the resonance space communicated with the first suction port of the casing of the centrifugal blower to enter the resonance space. The sound wave level of the incident noise can be reduced by air column resonance. At the same time, the sound wave level can be reduced by irregularly reflecting the sound wave of noise in the resonance space. Therefore, the two effects of air column resonance and irregular reflection can enhance the noise reduction effect in the high frequency range of noise associated with the operation of the centrifugal blower, and reduce the noise in a wide frequency range from low frequency to high frequency.
　本発明のこれらの態様と特徴は、添付された図面についての好ましい実施形態に関連した次の記述から明らかになる。この図面においては、
本発明の第１実施形態にかかる遠心送風機の模式断面図であり、 図１Ａの遠心送風機のＸ部分の拡大図であり、 本発明の第１実施形態のオリフィスの模式斜視図であり、 図２ＡのオリフィスにおけるＡ－Ａ断面図であり、 本発明の第１実施形態の遠心送風機における突起及び窪みの形状を示す模式斜視図であり、 本発明の第１実施形態の遠心送風機における騒音の低減効果を示す図であり、 本発明の第１実施形態の変形例にかかるオリフィスの模式斜視図であり、 本発明の第１実施形態の変形例にかかる遠心送風機の模式断面図であり、 本発明の第２実施形態のオリフィスの模式斜視図であり、 図７ＡのオリフィスにおけるＢ－Ｂ線断面図であり、 本発明の第３実施形態のオリフィスの模式斜視図であり、 本発明の第４実施形態の遠心送風機における突起及び窪みを示す模式断面図であり、 本発明の第４実施形態の遠心送風機において、突起内に空洞を構成する例を示す模式図であり、 従来の遠心送風機を示す模式断面図である。 These aspects and features of the invention will become apparent from the following description, taken in conjunction with the preferred embodiments with reference to the accompanying drawings, in which: In this drawing,
It is a schematic cross section of the centrifugal blower according to the first embodiment of the present invention, It is an enlarged view of X part of the centrifugal blower of FIG. 1A, It is a schematic perspective view of the orifice of the first embodiment of the present invention, It is AA sectional drawing in the orifice of FIG. 2A, It is a model perspective view which shows the shape of the processus | protrusion and the hollow in the centrifugal blower of 1st Embodiment of this invention, It is a figure which shows the reduction effect of the noise in the centrifugal blower of 1st Embodiment of this invention, It is a model perspective view of the orifice concerning the modification of 1st Embodiment of this invention, It is a schematic cross section of a centrifugal blower according to a modification of the first embodiment of the present invention, It is a model perspective view of the orifice of 2nd Embodiment of this invention, FIG. 7B is a sectional view taken along line BB in the orifice of FIG. 7A; It is a model perspective view of an orifice of a 3rd embodiment of the present invention, It is a schematic cross section which shows the protrusion and the hollow in the centrifugal blower of 4th Embodiment of this invention, In the centrifugal blower of the fourth embodiment of the present invention, it is a schematic diagram showing an example of forming a cavity in the protrusion, It is a schematic cross section which shows the conventional centrifugal blower.
　本発明の記述を続ける前に、添付図面において同じ部品については同じ参照符号を付している。 Before continuing the description of the present invention, the same parts are denoted by the same reference numerals in the accompanying drawings.
　以下に、本発明にかかる実施の形態を図面に基づいて詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
（第１実施形態）
　本発明の第１の実施形態にかかる遠心送風機１の模式断面図を図１Ａに示し、図１ＡのＸ部分の部分拡大図を図１Ｂに示す。図１Ａに示すように、例えば、天井埋込型換気扇として用いられる遠心送風機１は、下面に開口２を備えた外郭３内に、回転軸４を中心に回動可能に多翼型の羽根車５を連結した電動機６と、羽根車５の周囲を囲み、開口にベルマウス状の吸込み口７（第１の吸込み口）を有し、かつ側壁８に吐出口９を有するケーシング１０とを備えている。ケーシング１０の吐出口９は外郭３の一側面に設けられた吐出開口１１を介して、吐出アダプタ１２と連通している。外郭３の下面の外周にはフランジ部１３があり、フランジ部１３に備えた穴１４を通して、ねじ等で天井材１５に外郭３が固定され、天井に配され屋外に連通するダクト１６が、吐出アダプタ１２を介して吐出口９に接合されている。 (First embodiment)
A schematic cross-sectional view of the centrifugal blower 1 according to the first embodiment of the present invention is shown in FIG. 1A, and a partially enlarged view of a portion X in FIG. 1A is shown in FIG. 1B. As shown in FIG. 1A, for example, a centrifugal blower 1 used as a ceiling-embedded ventilation fan has a multi-blade impeller that can rotate around a rotating shaft 4 in an outer shell 3 having an opening 2 on a lower surface. And a casing 10 having a bell mouth-like suction port 7 (first suction port) in the opening and a discharge port 9 in the side wall 8. ing. The discharge port 9 of the casing 10 communicates with the discharge adapter 12 through a discharge opening 11 provided on one side surface of the outer shell 3. A flange portion 13 is provided on the outer periphery of the lower surface of the outer shell 3, and the outer shell 3 is fixed to the ceiling material 15 with screws or the like through a hole 14 provided in the flange portion 13, and a duct 16 disposed on the ceiling and communicating with the outside is discharged. It is joined to the discharge port 9 via the adapter 12.
　また、ケーシング１０の吸込み口７と同心円でベルマウス状の吸込み口１７（第２の吸込み口）を備えるオリフィス１８が、外郭３の開口２に配置されている。すなわち、外郭３の開口２は、オリフィス１８の吸込み口１７を通して、ケーシング１０の吸込み口７と連通されている。また、図１Ａおよび図１Ｂに示すように、オリフィス１８の端部２０はケーシング１０の吸込み口７の下面から間隙寸法ｊを隔てて位置しており、オリフィス１８とケーシング１０との間に間隙部（隙間）２１が形成されている。 Further, an orifice 18 that is concentric with the suction port 7 of the casing 10 and includes a bell mouth-shaped suction port 17 (second suction port) is disposed in the opening 2 of the outer shell 3. That is, the opening 2 of the outer shell 3 communicates with the suction port 7 of the casing 10 through the suction port 17 of the orifice 18. 1A and 1B, the end portion 20 of the orifice 18 is located at a gap dimension j from the lower surface of the suction port 7 of the casing 10, and the gap portion is provided between the orifice 18 and the casing 10. A (gap) 21 is formed.
　また、オリフィス１８の外周には、オリフィス１８、ケーシング１０、および外郭３のそれぞれを画定壁として、これらに囲まれて画定された共鳴空間１９が形成されている。この共鳴空間１９は、オリフィス１８とケーシング１０との間の間隙部２１を通じて、ケーシング１０の吸込み口７に連通されている。 Further, on the outer periphery of the orifice 18, a resonance space 19 defined by being surrounded by the orifice 18, the casing 10, and the outer shell 3 is defined. The resonance space 19 communicates with the suction port 7 of the casing 10 through a gap 21 between the orifice 18 and the casing 10.
　また、共鳴空間１９内には、画定壁上に複数の突起（突起部）２２が形成されており、隣接する突起２２の間には、窪み（凹部）２３が形成されている。ここで、オリフィス１８の模式斜視図を図２Ａに示し、図２Ａのオリフィス１８におけるＡ－Ａ線断面図を図２Ｂに示す。図２Ａおよび図２Ｂに示すように、オリフィス１８の共鳴空間１９内部側には、複数の突起２２および窪み２３が連続に形成されている。また、本第１実施形態では、それぞれの突起２２とオリフィス１８は一体成型された一つの部品である。また、突起２２は平面視にてその幅よりも奥行き方向（平面における一方向）に長い形状を有している。また、このような奥行き方向に長い形状を有する突起２２は、その奥行き方向を平行として３本一組で配列された複数の突起群（突起部群）３０としてオリフィス１８上に配置されており、図２Ａに示すように、隣接する突起群３０同士の奥行き方向が互いに略直交するように配列されている。 In the resonance space 19, a plurality of protrusions (protrusions) 22 are formed on the defining wall, and a recess (recess) 23 is formed between adjacent protrusions 22. Here, a schematic perspective view of the orifice 18 is shown in FIG. 2A, and a cross-sectional view taken along line AA in the orifice 18 of FIG. 2A is shown in FIG. 2B. As shown in FIGS. 2A and 2B, a plurality of protrusions 22 and depressions 23 are continuously formed on the inside of the resonance space 19 of the orifice 18. Further, in the first embodiment, each protrusion 22 and the orifice 18 are one part integrally molded. In addition, the protrusion 22 has a shape that is longer in the depth direction (one direction in the plane) than the width in plan view. In addition, the protrusions 22 having such a long shape in the depth direction are arranged on the orifice 18 as a plurality of protrusion groups (protrusion part groups) 30 arranged in a set of three with the depth direction being parallel. As shown in FIG. 2A, the adjacent protrusion groups 30 are arranged so that the depth directions thereof are substantially orthogonal to each other.
　ここで、突起２２の拡大図を図３に示す。図３に示すように突起２２は、突起高さｈｏ（図示Ｚ方向の高さ）に対して突起奥行きＬ（図示Ｙ方向の長さ）が長い形状を有している。また、突起２２は、その奥行き方向（Ｙ方向）に垂直な断面形状（ＸＺ断面形状）が台形となっている。突起２２の頂部は平坦面３１とされており、幅ａを有する頂部平坦面３１が、下方に向かうに従い幅ｃだけ両側に広がるように、突起２２の両側面（Ｘ方向の両側面）に、Ｚ方向に対して傾斜された傾斜面３２が形成されている。また、その奥行き方向が互いに平行に配置された２つの突起２２の間には、２つの傾斜面３２により略Ｖ字形状断面を有する窪み２３が形成されている。窪み２３の上部の開口幅はｂであり、Ｚ方向下方側へ向かうほど徐々に狭くなり、２つの傾斜面３２が窪み角度αで交わる。なお、窪み角度αは鋭角である。 Here, an enlarged view of the protrusion 22 is shown in FIG. As shown in FIG. 3, the protrusion 22 has a shape in which the protrusion depth L (the length in the Y direction in the drawing) is longer than the protrusion height ho (the height in the Z direction in the drawing). Further, the protrusion 22 has a trapezoidal cross-sectional shape (XZ cross-sectional shape) perpendicular to the depth direction (Y direction). The top of the projection 22 is a flat surface 31, and the top flat surface 31 having a width a is spread on both sides by a width c as it goes downward, on both side surfaces (both side surfaces in the X direction) of the projection 22. An inclined surface 32 inclined with respect to the Z direction is formed. In addition, a recess 23 having a substantially V-shaped cross section is formed by two inclined surfaces 32 between two protrusions 22 arranged in parallel in the depth direction. The opening width of the upper portion of the recess 23 is b, and gradually decreases toward the lower side in the Z direction, and the two inclined surfaces 32 intersect at the recess angle α. The depression angle α is an acute angle.
　次に、このような構成を有する遠心送風機１において、羽根車５の回転駆動により生じる騒音を、共鳴空間１９および共鳴空間１９内に設けられた複数の突起２２により低減させる作用について説明する。遠心送風機１において、電動機６により羽根車５が回転すると、吸込空気は本体開口２からオリフィス１８の吸込み口１７を通り、ケーシング１０の吸込み口７より羽根車５に入り、羽根車５により昇圧され、ケーシング１０の内部を通り、吐出アダプタ１２よりダクト１６に吐出され、屋外に排出される。 Next, in the centrifugal blower 1 having such a configuration, an operation of reducing noise generated by the rotational drive of the impeller 5 by the resonance space 19 and the plurality of protrusions 22 provided in the resonance space 19 will be described. In the centrifugal blower 1, when the impeller 5 is rotated by the electric motor 6, the intake air passes from the main body opening 2 through the suction port 17 of the orifice 18, enters the impeller 5 through the suction port 7 of the casing 10, and is boosted by the impeller 5. , Passes through the inside of the casing 10 and is discharged from the discharge adapter 12 to the duct 16 and discharged to the outdoors.
　この時、羽根車５で昇圧される際に発生する回転騒音や、ケーシング１０の内部を通る際に発生する渦による乱流騒音や、ケーシング１０内で共鳴により増幅された騒音の音波が、吸込み口７から下方に放射される。ケーシング１０の吸込み口７から放射された騒音の音波の一部はオリフィス１８の端部２０とケーシング１０との間で構成される間隙部２１から共鳴空間１９へ入射する。入射した音波の一部は共鳴空間１９内部の壁面（画定壁面）での固定端反射によって逆位相音波となり間隙部２１へ戻る。これにより、吸込み口７から放射される音波の一部を打ち消す気柱共鳴による共鳴消音が起こるため、騒音の音波レベルを低減することができる。なお、打ち消される音波の周波数は、間隙部２１から反射が起こる位置までの音波の経路距離によって決まる。さらに、共鳴空間１９内に突起２２が多数存在するため、共鳴空間１９内に入射した音波が多数の突起２２により反射を起こしやすく、さらに間隙部２１と突起２２の距離も様々であるため、様々な周波数の騒音を低減することができる。 At this time, rotational noise generated when the pressure is increased by the impeller 5, turbulent noise due to vortex generated when passing through the inside of the casing 10, and sound waves of noise amplified by resonance in the casing 10 are sucked in. Radiated downward from the mouth 7. A part of the sound wave of the noise radiated from the suction port 7 of the casing 10 enters the resonance space 19 from a gap 21 formed between the end 20 of the orifice 18 and the casing 10. A part of the incident sound wave becomes an antiphase sound wave by the fixed end reflection on the wall surface (definition wall surface) inside the resonance space 19 and returns to the gap portion 21. As a result, resonance silence due to air column resonance that cancels part of the sound wave emitted from the suction port 7 occurs, so that the sound wave level of the noise can be reduced. The frequency of the canceled sound wave is determined by the sound wave path distance from the gap 21 to the position where the reflection occurs. Further, since there are a large number of protrusions 22 in the resonance space 19, the sound waves incident in the resonance space 19 are likely to be reflected by the large number of protrusions 22, and the distance between the gap portion 21 and the protrusions 22 varies. It is possible to reduce noise at a high frequency.
　また、突起２２へ衝突した音波の一部は、その入射角によっては、反射した後、隣り合う突起２２へ向かい、その後も反射を繰り返し続ける乱反射によって窪み２３内でエネルギーが漸減されるため、騒音を低減することができる。 Further, depending on the incident angle, a part of the sound wave colliding with the protrusion 22 is reflected and then directed to the adjacent protrusion 22, and energy is gradually reduced in the recess 23 due to irregular reflection that continues to be reflected thereafter. Can be reduced.
　また、それぞれの窪み２３が略Ｖ字形状の断面を有するように隣接する突起２２が連続的に配列され、さらに窪み２３の幅が狭く設定されている。これにより、窪み２３に入射した音波がより多くの回数反射され、乱反射を生じさせることができ、減音効果が強く働き騒音を低減できる。例えば、突起高さｈｏと窪み開口幅ｂとに関して、ｈｏ≧ｂという関係であることが好ましい。 Further, adjacent protrusions 22 are continuously arranged so that each recess 23 has a substantially V-shaped cross section, and the width of the recess 23 is set to be narrow. As a result, the sound wave incident on the depression 23 is reflected more times, causing irregular reflection, and the sound reduction effect is strong and noise can be reduced. For example, the relationship of ho ≧ b is preferable with respect to the protrusion height ho and the recess opening width b.
　また、突起２２は、突起２２の奥行き方向に垂直な断面形状が台形であり、突起２２により形成される窪み２３の形状が下方側へ向かうほど徐々に狭くなっている。そのため、窪み２３に入射した音波が乱反射され、音波が窪み２３の下方側に進むほど反射が発生する時間間隔が短くなる。これにより、反射の回数が増え減音効果が強く働くため、騒音を低減できる。例えば、突起２２の断面形状の台形について、突起高さｈｏと傾斜面３２の幅ｃに関して、ｈｏ≧ｃという関係であることが好ましい。 Further, the protrusion 22 has a trapezoidal cross-sectional shape perpendicular to the depth direction of the protrusion 22, and the shape of the recess 23 formed by the protrusion 22 is gradually narrowed toward the lower side. Therefore, the sound wave incident on the depression 23 is diffusely reflected, and the time interval at which the reflection occurs becomes shorter as the sound wave travels to the lower side of the depression 23. Thereby, since the frequency | count of reflection increases and the sound reduction effect acts strongly, noise can be reduced. For example, the trapezoidal shape of the cross section of the protrusion 22 preferably has a relationship of ho ≧ c with respect to the protrusion height ho and the width c of the inclined surface 32.
　なお、突起２２の断面形状を三角形としても同様の効果が期待できる。ただし、突起２２の断面形状を台形とすることにより、傾斜面３２の角度を最適な角度に保持しながら、突起２２の頂部平坦面３１の幅ａを調整することで、窪み２３の容積を調整することができる。気柱共鳴による共鳴消音の実現のためには、共鳴空間１９を最適な容積に設定する必要があり、容積の最適化のためには、窪み２３の容積を調整する必要がある。そのため、突起２２の断面形状を台形とすることで、共鳴空間１９の容積の最適化のための調整を容易に行うことが可能となる。なお、窪み２３を形成する突起２２の傾斜面は平坦な面として形成される場合だけでなく、傾斜面を曲面としても同様の効果が期待できる。 It should be noted that the same effect can be expected when the cross-sectional shape of the protrusion 22 is triangular. However, the volume of the recess 23 is adjusted by adjusting the width a of the top flat surface 31 of the protrusion 22 while keeping the angle of the inclined surface 32 at an optimum angle by making the cross-sectional shape of the protrusion 22 trapezoidal. can do. In order to realize resonance silencing by air column resonance, it is necessary to set the resonance space 19 to an optimal volume, and to optimize the volume, it is necessary to adjust the volume of the recess 23. Therefore, by making the cross-sectional shape of the protrusion 22 trapezoidal, adjustment for optimizing the volume of the resonance space 19 can be easily performed. Note that the same effect can be expected when the inclined surface of the protrusion 22 forming the recess 23 is not only formed as a flat surface but also when the inclined surface is a curved surface.
　また、窪み２３の窪み角度αを鋭角とすることにより、窪み２３に対して入射角が浅い音波に対しても乱反射が発生しやすくなるため、減音効果が得られやすくなり、騒音を効果的に低減できる。 In addition, by setting the dent angle α of the dent 23 to be an acute angle, irregular reflection is likely to occur even for a sound wave having a shallow incident angle with respect to the dent 23, so that a sound reduction effect can be easily obtained and noise can be effectively obtained. Can be reduced.
　また、突起２２が、突起２２の高さ及び幅に対して奥行きが長い形状であるため、突起２２により形成される窪み２３がスリット状となる。そのため、突起２３の奥行き方向及びスリット方向（すなわち、Ｙ方向（図３参照））に対する入射角が浅い（小さい）音波に対しても乱反射を発生させることができる。その結果、減音効果が得られやすくなり、騒音を低減できる。例えば、突起奥行きＬ、突起高さｈｏ、突起先端幅ａに関して、Ｌ＞１．５ｈｏまたはＬ＞１．５ａという関係であることが好ましい。 Moreover, since the protrusion 22 has a shape that is long in depth with respect to the height and width of the protrusion 22, the recess 23 formed by the protrusion 22 has a slit shape. Therefore, irregular reflection can be generated even for a sound wave having a shallow (small) incident angle with respect to the depth direction of the protrusion 23 and the slit direction (that is, the Y direction (see FIG. 3)). As a result, a sound reduction effect can be easily obtained, and noise can be reduced. For example, regarding the protrusion depth L, the protrusion height ho, and the protrusion tip width a, it is preferable that L> 1.5ho or L> 1.5a.
　また、それぞれの突起２２の形状を同じとし、それぞれの突起２２により形成される窪み２３の形状をそれぞれ同じとする場合には、窪み２３での乱反射によって減音される音波の周波数が窪み２３の形状に依存するため、特定の周波数に対して減音効果が強く働き、騒音が低減できる。 In addition, when the shape of each protrusion 22 is the same and the shape of the recess 23 formed by each protrusion 22 is the same, the frequency of the sound wave reduced by the irregular reflection at the recess 23 is Since it depends on the shape, the sound reduction effect works strongly for a specific frequency, and noise can be reduced.
　また、間隙部２１から共鳴空間１９内に進入する音波は、オリフィス１８の端部２０（図１Ａおよび図１Ｂ参照）により、共鳴空間１９内においてオリフィス１８側へ回折する傾向がある。そのため、音波がオリフィス１８に衝突する可能性が高くなる。したがって、オリフィス１８上に複数の突起２２および窪み２３を形成することにより、音波を効果的に窪み２３内に入射させて、窪み２３による減音作用により騒音を低減できる。 Also, the sound wave entering the resonance space 19 from the gap 21 tends to be diffracted toward the orifice 18 in the resonance space 19 by the end 20 of the orifice 18 (see FIGS. 1A and 1B). Therefore, the possibility that the sound wave collides with the orifice 18 is increased. Therefore, by forming the plurality of protrusions 22 and the depressions 23 on the orifice 18, sound waves can be effectively incident on the depressions 23, and noise can be reduced by the sound reducing action of the depressions 23.
　また、図２Ａに示すように、突起２２とオリフィス１８とが一体成型された一つの部品として形成されていることにより、部品数を増やすことなく複数の突起２２および窪み２３を共鳴空間１９内に備えることができる。なお、例えば、図２Ｂに示すように、オリフィス１８の断面形状を一方向抜きの金型で製作できる形状とすることにより、製造が容易であり、製造コストを抑えることができる。 Further, as shown in FIG. 2A, since the protrusion 22 and the orifice 18 are formed as a single component, the plurality of protrusions 22 and the recesses 23 are formed in the resonance space 19 without increasing the number of components. Can be provided. For example, as shown in FIG. 2B, by making the cross-sectional shape of the orifice 18 a shape that can be manufactured by a die with one direction removed, the manufacturing is easy and the manufacturing cost can be reduced.
　また、突起２２が３本一組で構成された複数の突起群３０を縦横交互に配列する構成を採用することにより、１個の突起群３０により平行に配列されたスリット状の窪み２３を最大４本形成することができる。スリット状の窪み２３の長手方向に対し垂直に近い方向の音波ほど窪み２３による乱反射の発生率が高くなるという特性があり、突起２２を例えば４本以上一組にすることにより、さらにその特性が強くなる。また、スリット状の窪み２３の長手方向に対し平行に近い音波は乱反射の発生率が比較的低いが、オリフィス１８に４本一組の窪み２３の集合を形成する突起群３０を縦横交互に配列することにより、隣り合う集合同士で発生率の低さを補うことができる。したがって、窪み２３による乱反射を効果的に発生させて、減音効果を得ることができる。 Further, by adopting a configuration in which a plurality of projection groups 30 each having a set of three projections 22 are alternately arranged in the vertical and horizontal directions, the slit-like depressions 23 arranged in parallel by one projection group 30 are maximized. Four can be formed. There is a characteristic that the incidence rate of irregular reflection by the depression 23 becomes higher as the sound wave in a direction near to the longitudinal direction of the slit-like depression 23 becomes higher, and for example, by combining four or more protrusions 22, the characteristic is further improved. Become stronger. In addition, although the incidence of irregular reflection is relatively low for sound waves that are nearly parallel to the longitudinal direction of the slit-like depressions 23, the projection groups 30 that form a set of four depressions 23 in the orifice 18 are arranged alternately vertically and horizontally. By doing so, it is possible to compensate for the low occurrence rate between adjacent sets. Therefore, irregular reflection by the depression 23 can be effectively generated, and a sound reduction effect can be obtained.
　本第１実施形態に遠心送風機１において、例えば、外郭３の内寸を２６４ｍｍ角、高さを１９５ｍｍ、羽根車５の直径を１８３．５ｍｍ、吸込み口７の内径Ｄｉを１５２ｍｍ、吸込み口１７の内径Ｄｏを１５２ｍｍ、間隙寸法ｊを５ｍｍとし、突起高さｈｏを２０ｍｍ、突起頂部平坦面幅ａを１４ｍｍ、突起奥行きＬを６６ｍｍ、窪み角度αを４１°とした実施例の遠心送風機と、突起２２が設けられていない（その他の条件は実施例と同じ）比較例の遠心送風機との騒音特性値のグラフを図４に示す。実線は突起２２及び窪み２３を備える実施例の遠心送風機の騒音特性値であり、点線は突起および窪みを備えない比較例の遠心送風機の騒音特性値である。図４から明らかなように、実施例の騒音特性は、様々な周波数の音圧レベルが低減しており、特に１ｋＨｚ～１．４ｋＨｚと２．６ｋＨｚ～３．４ｋＨｚの比較的高周波域での減音が、比較例に比して顕著であることが判る。よって、本第１実施形態の遠心送風機の構成を採用することにより、オーバーオールで１ｄＢの騒音低減効果が得られることを確認できた。 In the centrifugal blower 1 according to the first embodiment, for example, the inner dimension of the outer shell 3 is 264 mm square, the height is 195 mm, the diameter of the impeller 5 is 183.5 mm, the inner diameter Di of the suction port 7 is 152 mm, and the suction port 17 The centrifugal blower of the example in which the inner diameter Do is 152 mm, the gap dimension j is 5 mm, the projection height ho is 20 mm, the projection top flat surface width a is 14 mm, the projection depth L is 66 mm, and the depression angle α is 41 °. FIG. 4 shows a graph of noise characteristic values of the centrifugal blower of the comparative example in which 22 is not provided (the other conditions are the same as those of the example). The solid line is the noise characteristic value of the centrifugal fan of the example having the protrusions 22 and the depressions 23, and the dotted line is the noise characteristic value of the centrifugal fan of the comparative example having no protrusions and depressions. As can be seen from FIG. 4, the noise characteristics of the embodiment are reduced in sound pressure levels at various frequencies, particularly in the relatively high frequency ranges of 1 kHz to 1.4 kHz and 2.6 kHz to 3.4 kHz. It can be seen that the sound is more prominent than the comparative example. Therefore, it has been confirmed that by adopting the configuration of the centrifugal blower of the first embodiment, a noise reduction effect of 1 dB can be obtained in overall.
　なお、図５に示すように、それぞれの突起群３０の突起２２の奥行き方向が、羽根車５の径方向に平行な方向および直交する方向から傾斜された方向に配置されるように、それぞれの突起群３０を配置させるようにすることもできる。このような構成においても上述の構成と同様な効果が期待できる。なお、このような傾斜された方向の傾斜角度は任意の角度を採用することができる。 As shown in FIG. 5, the depth direction of the protrusion 22 of each protrusion group 30 is arranged in a direction parallel to the radial direction of the impeller 5 and in a direction inclined from the orthogonal direction. The protrusion group 30 can also be arranged. Even in such a configuration, the same effect as the above-described configuration can be expected. An arbitrary angle can be adopted as the inclination angle in the inclined direction.
　また、図１の遠心送風機１の構成では、共鳴空間１９内においてオリフィス１８上に複数の突起２２が形成されるような場合について説明したが、このような場合に代えて、図６に示すように、オリフィス１８上に加えて、外郭３上およびケーシング１０上にも突起２２が形成されるような構成を採用することもできる。このような構成を採用することにより、気柱共鳴及び乱反射による減音がより発生しやすくなるため、さらなる減音効果が得られ、効果的に騒音を低減できる。 Further, in the configuration of the centrifugal blower 1 of FIG. 1, the case where a plurality of protrusions 22 are formed on the orifice 18 in the resonance space 19 has been described, but instead of such a case, as shown in FIG. 6. In addition to the orifice 18, a configuration in which the protrusions 22 are also formed on the outer shell 3 and the casing 10 can be adopted. By adopting such a configuration, sound reduction due to air column resonance and irregular reflection is more likely to occur, so that a further sound reduction effect can be obtained and noise can be effectively reduced.
　本第１実施形態によれば、気柱共鳴による減音効果および乱反射により減音効果を併用することにより、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができる遠心送風機が得られる。 According to the first embodiment, the sound reduction effect by air column resonance and the sound reduction effect by diffuse reflection are used together to enhance the sound reduction effect in the high frequency range and reduce the noise in a wide frequency range from low frequency to high frequency. A centrifugal blower can be obtained.
（第２実施形態）
　次に、本発明の第２の実施形態にかかる遠心送風機について説明する。以下の説明において、上記第１実施形態と同じ構成部材には同じ参照番号を付して、その説明を省略する。本第２実施形態の遠心送風機が備えるオリフィス１８の模式斜視図を図７Ａに示し、図７Ａのオリフィス１８におけるＢ－Ｂ線断面図を図７Ｂに示す。 (Second Embodiment)
Next, a centrifugal blower according to a second embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. FIG. 7A shows a schematic perspective view of the orifice 18 included in the centrifugal blower of the second embodiment, and FIG. 7B shows a cross-sectional view taken along the line BB in the orifice 18 of FIG. 7A.
　図７Ａにおいて、オリフィス１８の共鳴空間１９の内部側に複数の突起２２が不連続に、すなわち突起２２の側面が隣接する突起２２の側面と直接接続されないように備えられており、それぞれの突起２２の間には、隣接するそれぞれの突起２２の側面と底面とにより形成された窪み２３が備えられている。また、突起２２とオリフィス１８は一体成型された一つの部品として形成されている。また、個々の突起２２は、その形状が互いに異なっており、複数種類の形状を有する突起２２が設けられている。そのため、突起２２によって形成される窪み２３の形状も複数種類存在する。例えば、図７Ｂの断面図に示すように、複数の突起２２がそれぞれの側面が直接的に接続されることなく、間隔を空けて不連続に設けられている。さらに、羽根車５の径方向に関してそれぞれの窪み２３が任意間隔に配列されている。また、それぞれの窪み２３が、そのスリット状の長手方向が様々な方向となるように配置されている。 In FIG. 7A, a plurality of protrusions 22 are provided discontinuously on the inner side of the resonance space 19 of the orifice 18, that is, the side surfaces of the protrusions 22 are not directly connected to the side surfaces of the adjacent protrusions 22. A recess 23 formed by a side surface and a bottom surface of each adjacent protrusion 22 is provided between the protrusions 22. Further, the protrusion 22 and the orifice 18 are formed as a single molded part. Further, the individual protrusions 22 have different shapes, and the protrusions 22 having a plurality of types of shapes are provided. For this reason, there are a plurality of types of shapes of the recesses 23 formed by the protrusions 22. For example, as shown in the cross-sectional view of FIG. 7B, the plurality of protrusions 22 are discontinuously provided at intervals without directly connecting the respective side surfaces. Further, the recesses 23 are arranged at arbitrary intervals in the radial direction of the impeller 5. Moreover, each hollow 23 is arrange | positioned so that the slit-shaped longitudinal direction may turn into various directions.
　このような本第２実施形態の突起２２および窪み２３の配置構成を採用することにより、間隙部２１から進入した騒音の音波が共鳴空間１９内部での回折や反射により様々な方向となるような場合であっても、そのスリット状の長手方向を様々な方向として、それぞれの窪み２３が配置されているため、様々な方向の音波に対しても減音効果が得られ、騒音を低減することができる。 By adopting such an arrangement configuration of the protrusions 22 and the depressions 23 of the second embodiment, the sound wave of the noise that has entered from the gap portion 21 has various directions due to diffraction and reflection inside the resonance space 19. Even in this case, since the respective recesses 23 are arranged with the slit-like longitudinal direction as various directions, a sound reduction effect can be obtained even for sound waves in various directions, and noise can be reduced. Can do.
　また、窪み２３での乱反射によって減音される音波の周波数は窪み２３の形状に依存するため、突起２２の形状が複数種類であり、突起２２により形成される窪み２３の形状が複数種類である構成が採用されている。このような構成により、上記第１実施形態の構成に比べて、様々な周波数において減音効果が得られ、より広い周波数範囲において騒音を低減できる。なお、それぞれの突起２２および窪み２３は、その長手方向が、羽根車５の径方向、周方向および軸方向の少なくともいずれか１つに対して異なるように配列されていれば、様々な方向の音波に対しての減音効果を得ることができる。 Moreover, since the frequency of the sound wave reduced by the irregular reflection at the depression 23 depends on the shape of the depression 23, there are a plurality of types of the projections 22, and there are a plurality of types of the depressions 23 formed by the projections 22. Configuration is adopted. With such a configuration, a sound reduction effect can be obtained at various frequencies as compared with the configuration of the first embodiment, and noise can be reduced in a wider frequency range. In addition, as long as each protrusion 22 and the hollow 23 are arranged so that the longitudinal direction is different from at least one of the radial direction, the circumferential direction, and the axial direction of the impeller 5, various directions can be provided. A sound reduction effect for sound waves can be obtained.
　本第２実施形態によれば、気柱共鳴による減音効果および乱反射により減音効果を併用して、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができる遠心送風機が得られる。 According to the second embodiment, the sound reduction effect by air column resonance and the sound reduction effect by diffuse reflection are used together to enhance the sound reduction effect in the high frequency range and reduce noise in a wide frequency range from low frequency to high frequency. A centrifugal blower that can be obtained is obtained.
（第３実施形態）
　次に、本発明の第３の実施形態にかかる遠心送風機について説明する。以下の説明において、上記第１実施形態と同じ構成部材には同じ参照番号を付して、その説明を省略する。本第３実施形態の遠心送風機が備えるオリフィス１８の模式斜視図を図８に示す。 (Third embodiment)
Next, a centrifugal blower according to a third embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. FIG. 8 shows a schematic perspective view of the orifice 18 included in the centrifugal blower of the third embodiment.
　図８に示すように、オリフィス１８の共鳴空間１９の内部側には、図２Ａに示す上記第１実施形態の突起２２の配列と同様に、同一形状の突起２２を一組の突起群３０として、複数の突起群３０が縦横交互に配置されている。上記第１実施形態では、このような複数の突起群３０が、オリフィス１８と一体的に形成されている構成が採用されていたが、本第３実施形態では突起群３０が着脱可能なユニット２４として構成されている点において、上記第１実施形態とは異なる構成が採用されている。具体的には、ユニット２４（突起群３０に相当）は、その奥行き方向を平行に配列された突起２２を３本備え、これらの突起２２により形成されるスリット状の窪み２３を奥行き方向に平行に２本備えている。オリフィス１８の共鳴空間１９内部側に、複数のユニット２４が、隣接するユニット２４同士の奥行き方向が交差するように縦横任意に配置されている。また、それぞれのユニット２４はオリフィス１８とねじ等の固定手段によって固定されるため、オリフィス１８から着脱可能である。 As shown in FIG. 8, on the inner side of the resonance space 19 of the orifice 18, the projections 22 having the same shape are formed as a set of projection groups 30 in the same manner as the arrangement of the projections 22 of the first embodiment shown in FIG. 2A. The plurality of protrusion groups 30 are alternately arranged in the vertical and horizontal directions. In the first embodiment, the configuration in which the plurality of projection groups 30 are formed integrally with the orifice 18 is employed. However, in the third embodiment, the unit 24 to which the projection group 30 can be attached and detached is provided. In the point comprised as follows, the structure different from the said 1st Embodiment is employ | adopted. Specifically, the unit 24 (corresponding to the protrusion group 30) includes three protrusions 22 arranged in parallel in the depth direction, and a slit-like depression 23 formed by these protrusions 22 is parallel to the depth direction. Two are provided. On the inner side of the resonance space 19 of the orifice 18, a plurality of units 24 are arbitrarily arranged vertically and horizontally so that the depth directions of the adjacent units 24 intersect each other. Each unit 24 is fixed to the orifice 18 by a fixing means such as a screw, so that it can be detached from the orifice 18.
　このような構成が採用されていることにより、それぞれのユニット２４の配置構成を様々な形態にすることが可能となり、１種類の形態のユニット２４で様々な窪み２３の配列を作り出すことができる。また、ユニット２４が着脱可能であるため、窪み２３の配列を変更することにより減音できる周波数が調整可能である。 By adopting such a configuration, the arrangement configuration of each unit 24 can be changed into various forms, and various arrangements of the recesses 23 can be created with one type of unit 24. Further, since the unit 24 is detachable, the frequency at which the sound can be reduced can be adjusted by changing the arrangement of the recesses 23.
　なお、ユニット２４をグラスウール等の吸音材とすることにより、窪み２３での乱反射によるエネルギーの漸減がより強くなるため減音効果が強く働き、騒音が低減できる。 It should be noted that by using the unit 24 as a sound absorbing material such as glass wool, the gradual decrease of energy due to irregular reflection at the recess 23 becomes stronger, so that the sound reduction effect works strongly and noise can be reduced.
　本第３実施形態によれば、気柱共鳴による減音効果および乱反射により減音効果を併用して、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができるとともに、低減される騒音の周波数が調整可能である遠心送風機が得られる。 According to the third embodiment, the sound reduction effect by air column resonance and the sound reduction effect by diffuse reflection are used together to enhance the sound reduction effect in the high frequency range, and reduce the noise in a wide frequency range from low frequency to high frequency. And a centrifugal blower in which the frequency of the noise to be reduced can be adjusted.
（第４実施形態）
　次に、本発明の第４の実施形態にかかる遠心送風機について説明する。以下の説明において、上記第１実施形態と同じ構成部材には同じ参照番号を付して、その説明を省略する。本第４実施形態の遠心送風機に設けられた突起２２および窪み２３の構造を示す模式断面図を図９Ａおよび図９Ｂに示す。 (Fourth embodiment)
Next, a centrifugal blower according to a fourth embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. 9A and 9B are schematic cross-sectional views showing the structures of the protrusions 22 and the recesses 23 provided in the centrifugal blower of the fourth embodiment.
　図９Ａに示すように、本第４実施形態の突起２２は、例えば板厚１ｍｍでその内部が空洞２５となっており、さらに突起先端面２６上に例えばφ１．５ｍｍの孔２７を備えている。また、突起２２は、空洞２５を容積部、孔２７を喉部とするヘルムホルツ共鳴構造を形成している。このような突起２２の構造は、例えば図９Ｂに示すように、オリフィス１８を薄板で成型してそれぞれの突起２２の上面を形成し、このオリフィス１８の図示下方側から板パーツ２８を取付けることにより、それぞれの突起２２の内部に容易に空洞２５を形成することができる。 As shown in FIG. 9A, the protrusion 22 of the fourth embodiment has a plate thickness of 1 mm, for example, and has a hollow 25 inside thereof, and further has a hole 27 of φ1.5 mm on the protrusion tip surface 26, for example. . Further, the protrusion 22 forms a Helmholtz resonance structure in which the cavity 25 is a volume part and the hole 27 is a throat part. For example, as shown in FIG. 9B, such a structure of the projection 22 is formed by forming the orifice 18 with a thin plate to form the upper surface of each projection 22 and attaching a plate part 28 from the lower side of the orifice 18 in the figure. The cavity 25 can be easily formed inside each projection 22.
　このような本第４実施形態の構成では、窪み２３による減音に加え、その内部が空洞２５とされ、さらに孔２７が形成されている。これにより、ヘルムホルツ共鳴構造による共鳴消音が付加されるため、さらなる減音効果が得られ、騒音が低減できる。 In the configuration of the fourth embodiment as described above, in addition to the sound reduction by the recess 23, the inside is a cavity 25 and a hole 27 is formed. Thereby, since the resonance muffling by Helmholtz resonance structure is added, the further sound reduction effect is acquired and noise can be reduced.
　したがって、本第４実施形態によれば、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができる遠心送風機が得られる。 Therefore, according to the fourth embodiment, it is possible to obtain a centrifugal blower capable of enhancing the noise reduction effect in the high frequency range and reducing noise in a wide frequency range from low frequency to high frequency.
　なお、上記様々な実施形態のうちの任意の実施形態を適宜組み合わせることにより、それぞれの有する効果を奏するようにすることができる。 It should be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.
　本発明は、高周波域の減音効果を高め、低周波から高周波までの広い周波数範囲で騒音を低減することができ、騒音を低減する遠心送風機を提供するものであり、空調機器や換気送風機器に利用可能である。 The present invention provides a centrifugal blower that enhances a sound reduction effect in a high frequency range, can reduce noise in a wide frequency range from low frequency to high frequency, and reduces noise. Is available.
　本発明は、添付図面を参照しながら好ましい実施形態に関連して充分に記載されているが、この技術の熟練した人々にとっては種々の変形や修正は明白である。そのような変形や修正は、添付した請求の範囲による本発明の範囲から外れない限りにおいて、その中に含まれると理解されるべきである。 Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.
　２００８年４月２２日に出願された日本国特許出願Ｎｏ．２００８－１１１０３２号の明細書、図面、及び特許請求の範囲の開示内容は、全体として参照されて本明細書の中に取り入れられるものである。 Japanese patent application No. filed on April 22, 2008. The disclosure of the specification, drawings, and claims of 2008-111032 are incorporated herein by reference in their entirety.

Claims (16)

  1. 　開口部を備える外郭と、
    　外郭内にて回転可能に支持された羽根車と、
    　羽根車を回転駆動する電動機と、
    　第１の吸込み口を有し、羽根車の周囲を囲むように外郭内に配置されたケーシングと、
    　ケーシングの第１の吸込み口との間に隙間を有するように外郭の開口部に配置され、外郭の開口部とケーシングの第１の吸込み口とを連通させる第２の吸込み口を有するベルマウス状のオリフィスとを備え、
    　第１の吸込み口と第２の吸込み口との間の隙間を通じて第１の吸込み口と連通されて、第１の吸込み口から放出される騒音を共鳴消音する共鳴空間が、オリフィス、ケーシング、および外郭を画定壁として画定され、共鳴空間の画定壁に複数の突起部が設けられている、遠心送風機。     An outer shell with an opening,
    An impeller supported rotatably in the outer shell;
    An electric motor for rotationally driving the impeller;
    A casing having a first suction port and disposed in the outer shell so as to surround the periphery of the impeller;
    A bell mouth shape having a second suction port which is disposed in an opening of the outer shell so as to have a gap between the first suction port of the casing and communicates the opening of the outer shell and the first suction port of the casing. With an orifice,
    A resonance space that communicates with the first suction port through a gap between the first suction port and the second suction port to resonate and muffle noise emitted from the first suction port. A centrifugal blower, wherein the outer wall is defined as a defining wall, and the plurality of protrusions are provided on the defining wall of the resonance space.
  2. 　複数の突起部は、各々の形成位置において共鳴空間の画定壁面に対して傾斜された傾斜面を有し、
    　１つの突起部の傾斜面と、この１つの突起部に隣接する別の１つの突起部の傾斜面とが互いに接続されて、それぞれの傾斜面により両突起部間に凹部が形成されている、請求項１に記載の遠心送風機。     The plurality of protrusions have inclined surfaces that are inclined with respect to the defining wall surface of the resonance space at each forming position,
    An inclined surface of one protruding portion and an inclined surface of another protruding portion adjacent to the one protruding portion are connected to each other, and a concave portion is formed between the protruding portions by each inclined surface. The centrifugal blower according to claim 1.
  3. 　凹部におけるそれぞれの傾斜面の接続部分の角度が鋭角である、請求項２に記載の遠心送風機。 The centrifugal blower according to claim 2, wherein an angle of a connecting portion of each inclined surface in the recess is an acute angle.
  4. 　突起部は、その頂部に平坦面を有する、請求項２に記載の遠心送風機。 The centrifugal blower according to claim 2, wherein the protrusion has a flat surface at the top.
  5. 　突起部は、その高さおよび幅に対してその奥行きが長い形状を有する、請求項２に記載の遠心送風機。 The centrifugal blower according to claim 2, wherein the protrusion has a shape whose depth is long with respect to its height and width.
  6. 　その奥行き方向を平行にして複数の突起部が配列された複数の突起部群が、隣接する突起部群同士の奥行き方向が互いに交差するように配置されている、請求項５に記載の遠心送風機。 The centrifugal blower according to claim 5, wherein the plurality of protrusion groups in which the plurality of protrusions are arranged in parallel with each other in the depth direction are arranged so that the depth directions of adjacent protrusion groups intersect each other. .
  7. 　その奥行き方向を平行にして複数の突起部が配列された複数の突起部群が、各々の奥行き方向が異なるように配置されている、請求項５に記載の遠心送風機。 The centrifugal blower according to claim 5, wherein a plurality of protrusion groups in which a plurality of protrusions are arranged in parallel in the depth direction are arranged so that each of the depth directions is different.
  8. 　複数の突起部の間に形成される複数の凹部が、画定壁面沿いに延在するように形成され、羽根車の径方向、周方向および軸方向の少なくとも１つの方向に対して、それぞれの凹部の延在方向が異なるように配列されている、請求項５に記載の遠心送風機。 A plurality of recesses formed between the plurality of protrusions are formed so as to extend along the demarcating wall surface, and each recess is provided in at least one of the radial direction, the circumferential direction, and the axial direction of the impeller. The centrifugal blower according to claim 5, wherein the extending directions are different from each other.
  9. 　複数の突起部の形状が同じであり、複数の突起部の間に形成される複数の凹部の形状が同じである、請求項１から８のいずれか１つに記載の遠心送風機。 The centrifugal blower according to any one of claims 1 to 8, wherein the plurality of protrusions have the same shape, and the plurality of recesses formed between the plurality of protrusions have the same shape.
  10. 　突起部の形状が複数種類あり、複数の突起部の間に形成される凹部の形状が複数種類ある、請求項１から８のいずれか１つに記載の遠心送風機。 The centrifugal blower according to any one of claims 1 to 8, wherein there are a plurality of types of protrusions, and there are a plurality of types of recesses formed between the plurality of protrusions.
  11. 　共鳴空間内において、オリフィス上に複数の突起部が設けられている、請求項１から８のいずれか１つに記載の遠心送風機。 The centrifugal blower according to any one of claims 1 to 8, wherein a plurality of protrusions are provided on the orifice in the resonance space.
  12. 　複数の突起部は、オリフィス、ケーシング、または外郭の画定壁と一体的に形成されている、請求項１から８のいずれか１つに記載の遠心送風機。 The centrifugal blower according to any one of claims 1 to 8, wherein the plurality of protrusions are integrally formed with an orifice, a casing, or a demarcation wall of the outer shell.
  13. 　突起部は、画定壁に着脱可能に設置されている、請求項１から８のいずれか１つに記載の遠心送風機。 The centrifugal blower according to any one of claims 1 to 8, wherein the protrusion is detachably installed on the defining wall.
  14. 　突起部が、吸音材にて形成されている、請求項１３に記載の遠心送風機。 The centrifugal blower according to claim 13, wherein the protrusion is formed of a sound absorbing material.
  15. 　突起部はその内部を空洞として形成され、この空洞と共鳴空間とを連通する孔部が突起部に形成されている、請求項１から８のいずれか１つに記載の遠心送風機。 The centrifugal blower according to any one of claims 1 to 8, wherein the protrusion is formed with a hollow inside, and a hole communicating with the cavity and the resonance space is formed in the protrusion.
  16. 　開口部を備える外郭と、外郭内にて回転可能に支持された羽根車と、第１の吸込み口を有し、羽根車の周囲を囲むように外郭内に配置されたケーシングと、ケーシングの第１の吸込み口との間に隙間を有するように外郭の開口部に配置され、外郭の開口部とケーシングの第１の吸込み口とを連通させる第２の吸込み口を有するベルマウス状のオリフィスとを備える遠心送風機において、第１の吸込み口と第２の吸込み口との間の隙間を通じて第１の吸込み口と連通され、オリフィス、ケーシング、および外郭を画定壁として画定される共鳴空間内に、羽根車の回転駆動に伴ってケーシングにて発生した騒音の音波を第１の吸込み口と第２の吸込み口との間の隙間を通じて入射させ、
    　共鳴空間内にて入射された騒音の音波のレベルを気柱共鳴により低減させるとともに、共鳴空間内にて騒音の音波を乱反射させることにより騒音の音波のレベルを低減させる、遠心送風機の騒音低減方法。     An outer shell having an opening, an impeller rotatably supported in the outer shell, a casing having a first suction port and being arranged in the outer shell so as to surround the periphery of the impeller, A bell mouth-shaped orifice having a second suction port which is disposed in an opening of the outer shell so as to have a gap between the first suction port and communicates the opening of the outer shell and the first suction port of the casing; In a resonance space defined by the orifice, the casing, and the outer shell as a demarcated wall, and communicated with the first suction port through a gap between the first suction port and the second suction port. The sound wave of the noise generated in the casing as the impeller rotates is incident through the gap between the first suction port and the second suction port,
    A noise reduction method for a centrifugal blower that reduces the sound wave level of noise incident in the resonance space by air column resonance and reduces the sound wave level of noise by irregularly reflecting the sound wave of noise in the resonance space. .
PCT/JP2009/001819 2008-04-22 2009-04-21 Centrifugal fan and method of reducing noise of centrifugal fan WO2009130891A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US12/920,163 US20110002775A1 (en) 2008-04-22 2009-04-21 Centrifugal fan and noise reduction method in centrifugal fan
CN2009801069514A CN101965461A (en) 2008-04-22 2009-04-21 Centrifugal fan and noise reduction method in centrifugal fan

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-111032 2008-04-22
JP2008111032A JP2009264121A (en) 2008-04-22 2008-04-22 Centrifugal blower, and method for reducing noise of centrifugal fan

Publications (2)

Publication Number Publication Date
WO2009130891A1 true WO2009130891A1 (en) 2009-10-29
WO2009130891A8 WO2009130891A8 (en) 2010-03-11

Family

ID=41216632

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/001819 WO2009130891A1 (en) 2008-04-22 2009-04-21 Centrifugal fan and method of reducing noise of centrifugal fan

Country Status (4)

Country Link
US (1) US20110002775A1 (en)
JP (1) JP2009264121A (en)
CN (1) CN101965461A (en)
WO (1) WO2009130891A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102192194A (en) * 2010-03-17 2011-09-21 广东松下环境***有限公司 Structure for reducing noise of ventilating fan
CN109595652A (en) * 2017-09-30 2019-04-09 宁波方太厨具有限公司 A kind of near-suction type oil smoke suction machine
CN112061365A (en) * 2020-08-10 2020-12-11 上海外高桥造船有限公司 Indoor noise reduction device for ocean passenger ship
CN113847810A (en) * 2021-10-11 2021-12-28 成都新仪征环保科技有限公司 Low-noise air-cooled heat dissipation device

Families Citing this family (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2468312A (en) 2009-03-04 2010-09-08 Dyson Technology Ltd Fan assembly
GB2476171B (en) 2009-03-04 2011-09-07 Dyson Technology Ltd Tilting fan stand
GB2483448B (en) 2010-09-07 2015-12-02 Dyson Technology Ltd A fan
GB2486019B (en) 2010-12-02 2013-02-20 Dyson Technology Ltd A fan
GB2498547B (en) 2012-01-19 2015-02-18 Dyson Technology Ltd A fan
PL2626644T3 (en) * 2012-02-07 2019-03-29 Trox Gmbh Ventilation component comprising a channel-shaped housing with surrounding coverings
GB2502103B (en) 2012-05-16 2015-09-23 Dyson Technology Ltd A fan
GB2532557B (en) * 2012-05-16 2017-01-11 Dyson Technology Ltd A fan comprsing means for suppressing noise
AU2013261587B2 (en) * 2012-05-16 2015-11-19 Dyson Technology Limited A fan
JPWO2014006650A1 (en) * 2012-07-03 2016-06-02 三菱電機株式会社 Air conditioner indoor unit and air conditioner equipped with the indoor unit
GB2503907B (en) 2012-07-11 2014-05-28 Dyson Technology Ltd A fan assembly
US9752494B2 (en) 2013-03-15 2017-09-05 Kohler Co. Noise suppression systems
US9388731B2 (en) 2013-03-15 2016-07-12 Kohler Co. Noise suppression system
JP6221046B2 (en) * 2013-03-19 2017-11-01 パナソニックＩｐマネジメント株式会社 Blower
GB2530906B (en) 2013-07-09 2017-05-10 Dyson Technology Ltd A fan assembly
KR101483413B1 (en) 2013-07-24 2015-01-16 주식회사 휴비츠 Silent resonant scanner
US9169750B2 (en) * 2013-08-17 2015-10-27 ESI Energy Solutions, LLC. Fluid flow noise mitigation structure and method
JP6244547B2 (en) * 2013-09-24 2017-12-13 パナソニックＩｐマネジメント株式会社 Single suction centrifugal blower
DE102013222207B4 (en) * 2013-10-31 2022-03-03 Mahle International Gmbh centrifugal fan
US20150140344A1 (en) * 2013-11-20 2015-05-21 Covidien Lp Coated medical devices
FR3014029B1 (en) * 2013-12-04 2015-12-18 Valeo Systemes Thermiques SUCTION PULSER FOR A DEVICE FOR HEATING, VENTILATION AND / OR AIR CONDITIONING OF A MOTOR VEHICLE
US20210355949A1 (en) * 2014-10-15 2021-11-18 Delta Electronics, Inc. Ventilation system
WO2016066213A1 (en) * 2014-10-31 2016-05-06 Arcelik Anonim Sirketi Improved suction muffler for use in a hermetically sealed compressor of a refrigeration appliance
US11168696B2 (en) 2014-11-10 2021-11-09 Bascom Hunter Technologies, Inc. Vane-axial fan with a fan housing and shroud having an integral acoustic treatment including a micro-perforated panel and a plurality of compartments in an annular backspace formed by a plurality of shrouds
JP6380222B2 (en) * 2015-04-28 2018-08-29 株式会社デンソー Air conditioner for vehicles
WO2017199444A1 (en) * 2016-05-20 2017-11-23 三菱電機株式会社 Centrifugal blower, air conditioner, and refrigeration cycle device
CN106337843A (en) * 2016-10-20 2017-01-18 中山市创为电子科技有限公司 Noise reduction device and bladeless fan using noise reduction device
JP6745908B2 (en) 2016-12-19 2020-08-26 三菱電機株式会社 Air conditioner
JP6958830B2 (en) * 2017-05-16 2021-11-02 群馬県 Composite sound absorbing material
US11473596B2 (en) 2017-07-31 2022-10-18 Trane International Inc. Combined secondary inlet bell and flow grid for a centrifugal fan or centrifugal compressor
WO2019192886A1 (en) * 2018-04-03 2019-10-10 Arcelik Anonim Sirketi An improved cylinder head used in a hermetically sealed compressor of a cooler appliance
CN108470559A (en) * 2018-04-25 2018-08-31 昆山海旭科技电子有限公司中山分公司 A kind of SMD buzzers
JP2020109259A (en) * 2018-12-28 2020-07-16 日本電産株式会社 Blower
KR102082666B1 (en) * 2019-02-08 2020-02-28 주식회사 힘펠 Blast Apparatus
CN115853829B (en) * 2022-12-27 2024-07-09 西安交通大学 Fan current collector and centrifugal fan

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4868201A (en) * 1971-12-15 1973-09-18
JPS4997514U (en) * 1972-12-09 1974-08-22
JPH0178292U (en) * 1987-11-13 1989-05-25
JPH02139212U (en) * 1989-04-25 1990-11-21
JPH0894146A (en) * 1994-09-21 1996-04-12 Matsushita Seiko Co Ltd Ceiling embedded type ventilating fan
JP3066804U (en) * 1999-07-19 2000-03-07 インダストリアル テクノロジー リサーチ インスティテュート Low noise fan filter device
JP2003091286A (en) * 2001-09-17 2003-03-28 Fumihiro Nakagawa Sound absorbing member
JP2006145657A (en) * 2004-11-17 2006-06-08 Sasakura Engineering Co Ltd Method for mounting sound absorbing wedges for anechoic room
JP2007065901A (en) * 2005-08-30 2007-03-15 Nec Fielding Ltd Silent computer structure

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3035657A (en) * 1959-12-22 1962-05-22 Sidney Roofing & Paper Company Acoustic panel
FR2191025B1 (en) * 1972-07-04 1975-03-07 Aerospatiale
US4303144A (en) * 1979-12-21 1981-12-01 Lockheed Corporation Apparatus for the retroreflection of sound
US5803721A (en) * 1996-10-29 1998-09-08 Enviroflex, Inc. Clean room fan unit
CN2367806Y (en) * 1999-05-20 2000-03-08 财团法人工业技术研究院 Low-noise fan-filter net machine set
JP4873845B2 (en) * 2004-10-01 2012-02-08 三菱電機株式会社 Air conditioner
US8123468B2 (en) * 2006-11-02 2012-02-28 Panasonic Corporation Centrifugal fan

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4868201A (en) * 1971-12-15 1973-09-18
JPS4997514U (en) * 1972-12-09 1974-08-22
JPH0178292U (en) * 1987-11-13 1989-05-25
JPH02139212U (en) * 1989-04-25 1990-11-21
JPH0894146A (en) * 1994-09-21 1996-04-12 Matsushita Seiko Co Ltd Ceiling embedded type ventilating fan
JP3066804U (en) * 1999-07-19 2000-03-07 インダストリアル テクノロジー リサーチ インスティテュート Low noise fan filter device
JP2003091286A (en) * 2001-09-17 2003-03-28 Fumihiro Nakagawa Sound absorbing member
JP2006145657A (en) * 2004-11-17 2006-06-08 Sasakura Engineering Co Ltd Method for mounting sound absorbing wedges for anechoic room
JP2007065901A (en) * 2005-08-30 2007-03-15 Nec Fielding Ltd Silent computer structure

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102192194A (en) * 2010-03-17 2011-09-21 广东松下环境***有限公司 Structure for reducing noise of ventilating fan
US9441642B2 (en) 2010-03-17 2016-09-13 Panasonic Ecology Systems Guangdong Co., Ltd. Structure for reducing noise of ventilating fan
CN109595652A (en) * 2017-09-30 2019-04-09 宁波方太厨具有限公司 A kind of near-suction type oil smoke suction machine
CN109595652B (en) * 2017-09-30 2024-01-16 宁波方太厨具有限公司 Near-suction type range hood
CN112061365A (en) * 2020-08-10 2020-12-11 上海外高桥造船有限公司 Indoor noise reduction device for ocean passenger ship
CN113847810A (en) * 2021-10-11 2021-12-28 成都新仪征环保科技有限公司 Low-noise air-cooled heat dissipation device
CN113847810B (en) * 2021-10-11 2024-03-08 成都新仪征环保科技有限公司 Low-noise air-cooled heat dissipation device

Also Published As

Publication number Publication date
JP2009264121A (en) 2009-11-12
CN101965461A (en) 2011-02-02
US20110002775A1 (en) 2011-01-06
WO2009130891A8 (en) 2010-03-11

Similar Documents

Publication Publication Date Title
WO2009130891A1 (en) Centrifugal fan and method of reducing noise of centrifugal fan
US8123468B2 (en) Centrifugal fan
JP3843941B2 (en) Centrifugal blower
JP5832804B2 (en) Centrifugal fan
JP5135966B2 (en) Centrifugal blower
JP6221046B2 (en) Blower
JP5748916B2 (en) Air conditioner indoor unit and air conditioner equipped with the indoor unit
CN106368967B (en) Pedestal and bladeless fan
JP2009197623A (en) Centrifugal blower
JP5952801B2 (en) Centrifugal fan
WO2010116604A1 (en) Air blowing device
CN106593929B (en) Pedestal and bladeless fan
JP5309516B2 (en) Centrifugal blower
JP4807208B2 (en) Multi-blade blower
JP5135967B2 (en) Centrifugal blower
JP2006211770A (en) Rotating machine and operation method therefor
CN110822506B (en) Volute for range hood, fan and range hood
JP5309737B2 (en) Centrifugal blower
WO2008053867A1 (en) Centrifugal fan
JP5151631B2 (en) Centrifugal blower
JP5478465B2 (en) Multiblade centrifugal fan and multiblade centrifugal blower
CN115853804A (en) Volute assembly, fan assembly and air treatment device
JP7414533B2 (en) Air blower
JP5272873B2 (en) Centrifugal blower
KR101199063B1 (en) Centrifugal fan and refrigerator hanving the same

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200980106951.4

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09734839

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 12920163

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09734839

Country of ref document: EP

Kind code of ref document: A1