JP5353137B2 - Recessed ceiling ventilation fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceiling embedded ventilation fan capable of expanding a frequency band enabling sound attenuation and reducing noise even when the state of a fan load is changed. <P>SOLUTION: The ceiling embedded ventilation fan 1 is provided with: a casing 8 having a suction port 15; a centrifugal impeller 7 arranged inside the casing 8; an electric motor 6 for rotating the centrifugal impeller 7; an orifice plate 16 with a communication hole 17 arranged between the casing 8 and an opening 3 of an outer hull 4; and a sound attenuation means arranged between the orifice plate 16 and the opening 3 of the outer hull 4. Due to this structure, the ceiling embedded ventilation fan 1 can perform resonance and sound attenuation of noise emitted from the suction port 15 of the casing 8 in a space between the casing 8 and the orifice plate 16, at the same time attenuate noise emitted from the communication hole 17 of the orifice plate 16 by the sound attenuation means, and expand the frequency band enabling sound attenuation. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a ceiling-embedded ventilation fan that is a ventilation fan installed mainly on the ceiling of a bathroom or toilet.

  2. Description of the Related Art Conventionally, this type of ceiling-embedded ventilation fan is known in which an orifice different from a suction casing having a bell mouth-shaped suction port is provided in an opening on one surface of an outer shell (see, for example, Patent Document 1). .

  The ceiling-embedded ventilation fan will be described below with reference to FIG. As shown in FIG. 8, an outer shell 101 having an open surface, an electric motor 104 having an impeller 103 fixed to a top surface 102 in the outer shell 101, a casing 105 surrounding the periphery of the impeller 103, and a suction port having a suction port 106. The ceiling-embedded ventilation fan including the casing 107 has an orifice 109 having a suction hole 108 that is equal to or smaller than the suction port 106, and a lower end 110 of the suction casing 107 and an end 111 of the orifice 109 separated by a gap 115 having a gap dimension i. The resonance space 112 having a height h is provided. Further, a grill 113 and a discharge port 114 provided on one side of the outer shell 101 are provided on one surface of the orifice 109.

In the above configuration, 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 is pressurized by the impeller 103. And discharged from the discharge port 114. At this time, rotational noise generated when the pressure is increased by the impeller 103, turbulent noise due to vortex generated when passing through the casing 105, and sound waves of noise generated in the casing 105 are radiated from the suction port 106, and A part of the light enters the resonance space 112 from the gap 115. Among the sound waves of the incident noise, the sound waves of the noise specified by the volume and shape of the gap 115 and the resonance space 112 undergo air column resonance in the resonance space 112 and are resonated.
Japanese Patent No. 3279834

  In such a conventional ceiling-embedded ventilation fan, the frequency band that can be silenced is specified by the volume and shape of the gap 115 and the resonance space 112, but the frequency characteristics of noise also change depending on the fan load that varies depending on external factors. When the frequency band that can be muffled deviates from the frequency of the generated noise, there is a problem that the noise reduction effect becomes small, and it is required to expand the frequency band that can mute.

  The present invention solves such conventional problems, and provides a ceiling-embedded ventilation fan that expands the frequency band that can be silenced and can reduce noise even when the fan load changes. It is aimed.

In order to achieve the above object, the ceiling-embedded ventilation fan of the present invention includes an outer shell having an opening, a power unit, a centrifugal impeller that is rotated by the power unit and blows air inside the outer shell, and a centrifugal impeller. A casing and an adapter that guides air from the casing to the duct and a suction grill that covers the opening of the outer shell, the casing has a suction port and a side wall that face the opening of the outer shell, and communicates between the suction port of the casing and the opening of the outer shell A ceiling-embedded ventilation fan provided with an orifice plate having holes, provided with a silencing means between the orifice plate and the opening of the outer shell , wherein the height Hc of the casing is smaller than the inner diameter Dd of the duct, and the silencing means is the orifice A plate-shaped sound-absorbing material that is installed so as to surround the communication hole of the plate and has a vent hole inside is laminated, and the inner diameter of the vent hole is close to the opening of the outer shell and the orifice plate. In is smaller, but it was ceiling ventilating fan, wherein forming the expansion silencer.

By this means, noise radiated from the suction port of the casing can be resonantly silenced in the space between the casing and the orifice plate, and noise having a frequency other than the frequency silenced by the resonance silencer radiated from the communication hole of the orifice plate can be silenced. A ceiling-embedded ventilation fan that can be muffled by the means and can expand the frequency band that can be muffled can be obtained. In addition, by this means, the space that can be used for silencing within the outer shell can be increased, so that a ceiling-embedded ventilation fan that can expand the frequency band that can be muted can be obtained. In addition, by this means, the noise embedded in the orifice hole of the orifice plate can be silenced by the sound absorbing material, and a ceiling-embedded ventilation fan that can expand the frequency band that can be silenced can be obtained. In addition, the height of the sound-absorbing material can be changed by this means, and the thickness of the sound-absorbing material in the radial direction is non-uniform by making the size of the ventilation holes of the sound-absorbing material non-uniform from the orifice plate to the outer opening. In addition, since the frequency at which the sound absorbing material is silenced can be made nonuniform, a ceiling-embedded ventilation fan capable of expanding the frequency band where noise can be silenced can be obtained. In addition, this means forms an expansion silencer in which the sound wave path rapidly expands while the sound wave radiated from the communication hole of the orifice plate by the vent hole of the sound absorbing material reaches the opening of the outer shell. A ceiling-embedded ventilation fan capable of expanding the band is obtained.

  Another means is a ceiling-embedded ventilation fan characterized in that a sound absorbing material is provided between the casing and the orifice plate.

  By this means, in addition to resonance noise reduction in the space between the casing and the orifice plate, noise reduction by the sound absorbing material can be added, and a ceiling-embedded ventilation fan that can expand the wave number band that can be silenced is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the frequency band which can be muffled can be expanded and the ceiling embedded type ventilation fan which can reduce noise even if the state of a fan load changes can be provided.

The invention according to claim 1 of the present invention includes an outer shell having an opening, a power unit, a centrifugal impeller that rotates by the power unit inside the outer shell and blows air, a casing that contains the centrifugal impeller, and air from the casing An orifice plate that includes an adapter that guides the air to the duct and a suction grill that covers the opening of the outer shell, the casing includes a suction port and a side wall facing the opening of the outer shell, and a communication hole between the suction port of the casing and the opening of the outer shell A ceiling-embedded ventilation fan equipped with a ceiling-embedded ventilation fan, which is equipped with a silencing means between the orifice plate and the outer opening. Resonance can be silenced in the space between the casing and the orifice plate, and noise radiated from the communication hole of the orifice plate and having a frequency other than the frequency silenced by the resonance can be silenced by the silencer. It can be silenced, an effect that it is possible to expand the frequency band that can be muted. Moreover, it is a ceiling-embedded ventilation fan characterized in that the height Hc of the casing is smaller than the inner diameter Dd of the duct, and since the space that can be used for silencing can be increased in the outer shell, the frequency band that can be silenced Can be enlarged. In addition, the silencer is a sound-absorbing material installed so as to surround the communication hole of the orifice plate, and is a ceiling-embedded ventilation fan, and noise radiated from the communication hole of the orifice plate is used as the sound-absorbing material. Therefore, the frequency band that can be muted can be expanded. Also, it is a ceiling-embedded ventilation fan characterized by laminating flat sound-absorbing materials with vents inside, and the height of the sound-absorbing material can be changed, and the size of the sound-absorbing material vent holes By making the thickness non-uniform from the orifice plate to the outer opening, the radial thickness of the sound absorbing material can be made non-uniform, and the frequency at which the sound absorbing material can mute can be made non-uniform, so the frequency band that can be silenced is expanded. It has the effect of being able to. In addition, the ventilation hole is a ceiling-embedded ventilation fan characterized in that the inner diameter of the ventilation hole is small in the vicinity of the opening of the outer shell and the vicinity of the orifice plate. The expansion type silencer in which the path of the sound wave rapidly expands while the radiated sound wave reaches the outer opening is formed, so that the frequency band that can be silenced can be expanded.

  Moreover, it is a ceiling-embedded ventilation fan characterized by having a sound absorbing material between the casing and the orifice plate, and in addition to the resonance noise reduction in the space between the casing and the orifice plate, the sound absorbing material can also be silenced. The wavenumber band that can be silenced can be expanded.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

( Premise form 1)
A premise mode 1 of the present invention will be described with reference to FIG. As shown in the figure, a ceiling-embedded ventilation fan 1 attached to a ceiling for ventilating a space such as a bathroom or a toilet has a 260 mm square outer wall 4 having an opening 3 on a lower surface 2 and a height of 200 mm, and an outer wall. 4, a flat top plate 5 that is horizontally fixed, an electric motor 6 that is fixed to the top plate 5, and a centrifugal blade that is rotatably fixed to the electric motor 6 with an outer diameter of φ183 mm and a height Hc of 60 mm. An adapter 13 that communicates with a car 7, a scroll-shaped casing 8 that is fixed so as to cover the centrifugal impeller 7, a discharge port 9 of the casing 8, a discharge port 11 of the side surface 10 of the outer shell 4, and a duct 12 having a nominal diameter of φ100 mm. And a suction grill 14 installed so as to cover the opening 3 of the outer shell 4.

  The inner diameter Dd of the duct is 107 mm, the casing height Hc is 75 mm, and the casing 8 is provided with a bell mouth-shaped suction port 15 having a suction port inner diameter Do of 150 mm.

  An orifice plate 16 is provided between the casing 8 and the opening 3 of the outer shell 4 so as to divide the outer shell 4 in the vertical direction at a distance H1 (30 mm) from the suction port 15 of the casing 8. The orifice plate 16 is provided with a bell mouth-shaped communication hole 17, the communication hole 17 is concentric with the same diameter as the suction port 15 of the casing 8, and the gap t 1 between the end 18 of the communication hole 17 and the casing 8 is 10 mm. There is a sound absorbing component 20 made of a sound absorbing material (for example, glass wool) between the casing 8 and the orifice plate 16.

  Further, between the orifice plate 16 and the opening 3 of the outer shell 4, there is provided a laminated sound absorber 23 in which a flat plate sound absorbing material 22 having a vent hole 21 concentric with the orifice plate 16 is laminated, and the inner diameter of the vent hole 21 is the orifice plate 16 side. Is gradually enlarged toward the opening 3 side of the outer shell 4 so as to be φ160 mm and φ220 mm on the opening 3 side of the outer shell 4.

  With the above configuration, when the centrifugal impeller 7 is rotated by applying a driving force from the electric motor 6, the sucked air is opened in the lower surface 2 of the outer shell 4, the vent hole 21 in the laminated sound absorber 23, and the communication hole 17 in the orifice plate 16. Then, the pressure is increased by being guided to the centrifugal impeller 7 sequentially through the suction port 15 of the casing 8, and the dynamic pressure is gradually converted to static pressure when passing through the scroll-shaped casing 8, and the discharge of the outer shell 4 from the discharge port 9. It is discharged from the duct 12 through the outlet 11 and the adapter 13.

  At this time, rotational noise of the centrifugal impeller 7, turbulent noise generated inside the casing 8, and sound waves of noise amplified by resonance in the casing 8 are radiated from the suction port 15 of the casing 8, A part of the light enters the space 19 defined by the orifice plate 16 from the gap t1, and a resonance-type silencing structure is formed by the gap t1 and the space 19. Therefore, among the sound waves of the incident noise, the resonance-type silencing A portion of the sound wave with a frequency that matches the resonant frequency of the structure is muted.

  The sound wave that has not been silenced is radiated from the communication hole 17 of the orifice plate 16, but part of the sound wave is silenced by the laminated sound absorber 23, so that the wave number band that can be silenced can be expanded, and the ceiling-embedded ventilation fan 1 Noise emitted to the outside of the machine is reduced.

  Further, since the height Hc of the casing 8 is smaller than the inner diameter Dd of the duct, the volume in which the laminated sound absorber 23 can be disposed can be increased, and the frequency band in which the sound can be silenced can be expanded.

  In addition, since the inner diameter of the vent hole 21 of the laminated sound absorber 23 gradually increases toward the opening 3 of the outer shell 4, the air flowing through the vent hole 21 can be smoothly guided to the communication hole 17 of the orifice plate 16, Moreover, since the thickness in the radial direction of the flat sound-absorbing material 22 is non-uniform in the stacking direction, the frequency at which each flat sound-absorbing material 22 is silenced can be made non-uniform, so the frequency band that can be silenced can be expanded.

In the premise 1 of the present invention, the communication hole 17 of the orifice plate 16 is concentric with the same diameter as the suction port 15 of the casing 8, but the inner diameter of the communication hole 17 of the orifice plate 16 is the same as that of the suction port 15 of the casing 8. The communication hole 17 of the orifice plate 16 may be larger than the inner diameter, and the same effect can be obtained even if the communication hole 17 of the orifice plate 16 is not concentric with the suction port 15 of the casing 8 and is slightly displaced.

  In addition, although the sound-absorbing material has a circular ventilation hole, the same effect can be obtained with other shapes such as a square.

In addition, although each dimension is shown as an example in the form of this premise , it is not limited to these dimensions, and the same effect can be obtained even if the dimensions are different as long as the configuration is the same.

(Embodiment 1 )
The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof is omitted. In the first embodiment of the present invention, as shown in FIG. 2, the inner diameter of the ventilation hole 21 of the laminated sound absorber 23 is small in the vicinity of the opening 3 of the outer shell 4 and in the vicinity of the orifice plate 16.

  With the above configuration, the vent 21 of the laminated sound absorber 23 forms an expansion silencer in which the sound wave path rapidly expands while the sound wave radiated from the communication hole 17 of the orifice plate 16 reaches the opening 3 of the outer shell 4. Therefore, in addition to the silencing effect of the laminated sound absorber 23, the silencing effect by the expansion silencer is added, so that the frequency band that can be silenced can be expanded.

( Reference form 1 )
The same parts as those in the first embodiment or the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 3, the reference form 1 of the present invention is a disc-shaped concentric circle with the communication hole 17 between the communication hole 17 of the orifice plate 16 and the opening 3 of the outer shell 4, and a sound absorbing material (for example, glass wool). The sound insulation board 24 produced in (1) is provided.

  With the above configuration, a part of the noise radiated from the communication hole 17 of the orifice plate 16 can be reflected by the sound insulation plate 24 and returned into the casing 8, and since the sound insulation plate 24 is a sound absorbing material, sound absorption due to sound absorption is prevented. In addition, the flow of air that goes around the outside of the sound insulating plate 24 becomes uniform, and the flow can be smoothly guided to the communication hole 17 of the orifice plate 16, and the frequency band that can be silenced can be expanded.

( Reference form 2 )
The same parts as those in the first embodiment, the first embodiment, and the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the fourth embodiment of the present invention, as shown in FIG. 4, the sound insulating plate 24 is convexly curved with respect to the opening 3 of the outer shell 4.

  With the above configuration, a part of the noise radiated from the communication hole 17 of the orifice plate 16 can be reflected toward the center of the communication hole 17 when reflected by the sound insulation plate 24. The wave number band that can be silenced can be expanded.

( Reference form 3 )
The same parts as those in the first embodiment or the first embodiment and the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. Embodiment 3 of the reference in the present invention, as shown in FIG. 5, provided with a communication hole 17 concentric with the circular tube 25 of the orifice plate 16 between the opening 3 of the orifice plate 16 and the outer 4, the middle of the circular tube 25 Is provided with a projecting portion 26 to constitute a side branch type silencer.

  With the above configuration, part of the noise radiated from the communication hole 17 of the orifice plate 16 can be silenced by the side branch type silencer, and the frequency band that can be silenced can be expanded.

( Reference form 4 )
The same parts as those in the first embodiment or the first embodiment and the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. Embodiment 4 Reference of the present invention, as shown in FIG. 6, between the opening 3 of the orifice plate 16 and the outer 4, the communicating hole 17 and concentric perforated circular tube 27 of the orifice plate 16, perforated circular pipe 27 Is provided with an outer circular tube 28 made of a sound-absorbing material (for example, glass wool), and an end is blocked so as to form a cylindrical space 29 between the porous circular tube 27 and the outer circular tube 28, and a porous resonance silencer Is forming. For example, the perforated circular tube 27 is formed by processing a punching metal having a hole diameter of φ4 mm and an aperture ratio of 40% into a cylindrical shape.

  With the above configuration, a part of the noise radiated from the communication hole 17 of the orifice plate 16 can be silenced by the porous resonance silencer, and since the outer circular tube 28 is a sound absorbing material, noise reduction by the sound absorbing material is added. The frequency band that can be silenced can be expanded.

( Reference form 5 )
The same parts as those in the first embodiment or the first embodiment and the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. Embodiment 5 Reference of the present invention, as shown in FIG. 7, between the opening 3 of the orifice plate 16 and the outer 4, the active noise reduction unit 30, the opening 3 of the shell 4 to the communication hole 17 of the orifice plate 16 A partition wall 32 of two sound-absorbing materials (for example, glass wool) is provided to form a flow path 31 so that the air wraps around in the horizontal direction.

  The active silencer unit 30 includes a first microphone 33 and a second microphone 34 that detect sound waves, an electrical unit 35 that includes a control circuit that generates sound waves of opposite phase from the detected sound waves, and a speaker that generates sound waves of opposite phase. 36, the first microphone 33 faces the communication hole 17 of the orifice plate 16 of the flow path 31, the speaker 36 faces the opening 3 side of the flow path 31, and the second microphone 34 is from the speaker 36. Is also disposed near the suction grille 14.

  With the above configuration, a sound wave radiated from the communication hole 17 by the first microphone 33 is detected, and the control circuit in the electrical unit 35 is transmitted by the first microphone 33 while the sound wave reaches the opening 3 through the flow path 31. Based on the detected sound wave, an additional sound wave is created so that noise is minimized at the position of the second microphone 34, and is radiated from the speaker 36. Further, the characteristic of the additional sound wave is adjusted from the detection signal of the second microphone 34 so that the noise is minimized. As a result, the sound wave radiated by the interference of the sound wave can be canceled, and the frequency band that can be silenced can be expanded.

  By integrating the first microphone 33, the second microphone 34, the electrical component 35, and the speaker 36, it is possible to reduce the size of components for active silencing, so that the volume for forming the flow path 31 can be increased. In addition, since the flow path 31 is formed by the partition wall 32 so that the air flows in the horizontal direction from the opening 3 of the outer shell 4 to the communication hole 17 of the orifice plate 16, the distance between the first microphone 33 and the speaker 36. Since the time required for the sound wave detected by the first microphone 33 to reach the opening 3 can be lengthened, an additional sound wave having a high frequency can be created, and a frequency band that can be muted can be set. Can be enlarged.

  Moreover, since the partition wall 32 is a sound absorbing material, a silencing effect by the sound absorbing material can also be added, and the frequency band that can be silenced can be expanded.

  The present invention provides a ceiling-embedded ventilation fan that can reduce noise even when the frequency band that can be silenced is expanded and the fan load changes, and various air-conditioning fans, air-conditioning equipment, and home appliances It can be applied to the blower built in.

Side sectional drawing which shows the ceiling embedded type ventilation fan of the form 1 of the premise of this invention 1 is a side sectional view showing a ceiling-embedded ventilation fan according to a first embodiment of the present invention. Side sectional drawing which shows the ceiling embedded type ventilation fan of the reference form 1 of this invention Side sectional drawing which shows the ceiling embedded type ventilation fan of the reference form 2 of this invention Sectional side view which shows the ceiling embedded type ventilation fan of the reference form 3 of this invention Sectional side view which shows the ceiling embedded type ventilation fan of the reference form 4 of this invention Side sectional drawing which shows the ceiling embedded type ventilation fan of the reference form 5 of this invention Side sectional view showing a conventional ceiling-mounted ventilation fan

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceiling embedded type ventilation fan 2 Lower surface 3 Opening 4 Outer shell 5 Top plate 6 Electric motor Hc Casing height 7 Centrifugal impeller 8 Casing 9 Discharge port 10 Side surface 11 Discharge port 12 Duct 13 Adapter 14 Suction grill Dd Duct inner diameter Do Suction inner diameter DESCRIPTION OF SYMBOLS 15 Suction port H1 space | interval 16 Orifice plate H2 space | interval 17 Communication hole 18 End part t1 Crevice 19 Space 20 Sound absorption component 21 Vent hole 22 Flat sound-absorbing material 23 Laminated sound absorber 24 Sound insulation plate 25 Circular pipe 26 Projection part 27 Porous circular pipe 28 Outer circle Tube 29 Cylindrical space 30 Active silencer unit 31 Flow path 32 Bulkhead 33 First microphone 34 Second microphone 35 Electrical component 36 Speaker

Claims (2)

An outer shell having an opening, a power unit, a centrifugal impeller that is rotated by the power unit and blows air inside the outer shell, a casing that contains the centrifugal impeller, and an adapter that guides air from the casing to a duct A suction grille covering the opening of the outer shell, the casing includes a suction port and a side wall facing the opening of the outer shell, and a communication hole between the suction port of the casing and the opening of the outer shell. A ceiling-embedded ventilation fan provided with an orifice plate, comprising a silencer means between the orifice plate and the opening of the outer shell,
The height Hc of the casing is smaller than the inner diameter Dd of the duct,
The sound deadening means is installed so as to surround the communication hole of the orifice plate, and is configured by laminating a plate-like sound absorbing material provided with a vent hole inside,
The ceiling-embedded ventilation fan, wherein an inner diameter of the vent hole is small in the vicinity of the opening of the outer shell and in the vicinity of the orifice plate to form an expansion silencer . Claim 1 Symbol mounting of ceiling ventilators characterized by comprising a sound absorbing material in the casing and the orifice plates.

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