JP6634596B2 - Blower - Google Patents

Description

  The present invention relates to a blower that reduces noise.

  2. Description of the Related Art In recent years, it has been required to reduce noise generated during operation of a blower such as an air conditioner and a ventilation fan. As one of means for solving such a problem, there is a method of mounting an active silencer having a duct structure in an internal air passage.

  2. Description of the Related Art Conventionally, as this type of active silencer, there has been known an active silencer in which a microphone is provided with a space provided at a position where airflow is relatively slow in order to reduce the influence of airflow in an air passage (for example, see Patent Document 1). .

  Hereinafter, the active silencer will be described with reference to FIGS.

  Conventionally, as an active silencer having a duct configuration, a reference microphone 111 of an internal original sound, a silencing speaker 112, an error microphone, which are sequentially provided at appropriate intervals from an upstream side inside a rectangular duct 101 made of a thin steel plate and are sequentially provided. There is known a configuration including a computer 113 and an arithmetic and control unit 102 to which these are connected. In this case, as shown in FIG. 9, in the case of the rectangular duct 101, a microphone section 104 is provided at a corner, and a reference microphone 111 and an error microphone 113 are provided.

  In this type of device, a sound wave propagating in the rectangular duct 101 together with the airflow 103 is detected by the reference microphone 111. In the arithmetic and control unit 102, a signal having the opposite phase is generated using the sound wave as an original sound, and the signal is emitted from the sound deadening speaker 112 into the rectangular duct 101 as a sound wave having the opposite phase. The opposite-phase sound wave exerts a sound-muffling effect on the original sound. The error microphone 113 monitors the sound in the rectangular duct 101 on the downstream side of the sound wave propagating from the muffling speaker 112, and the arithmetic and control unit 102 controls the error microphone 113 so that the output of the error microphone 113 becomes zero from the monitor sound. The signal of the opposite phase is adjusted.

  Thereby, the reference microphone 111 and the error microphone 113 do not detect the noise generated by the airflow in the duct, and can accurately detect only the noise original sound to be silenced. improves.

Japanese Utility Model Application Laid-Open No. 5-11198

  However, in the active noise reduction device described in Patent Literature 1, the distance between the points on the opposing surfaces becomes uniform in a cross section perpendicular to the air flow direction in the rectangular duct. The inside became a resonance space, and it was confirmed that a standing wave resonating at a specific frequency was generated. Then, due to the effect of the standing wave, it becomes impossible to accurately detect noise at the frequency corresponding to the standing wave. In this case, the correlation between the reference microphone and the muffling point deteriorates, and the muffling effect at that frequency is significantly reduced. In other words, there is a problem that the generated standing wave resonates on the opposing surfaces having a uniform distance, and the noise reduction effect is reduced due to the effect.

  Then, this invention solves the said subject, and an object of this invention is to provide the ventilation apparatus which improved the silencing effect of the active silencer while ensuring the desired air volume.

In order to achieve the above object, the blower according to the present invention has a suction port for sucking air, a discharge port for discharging air sucked from the suction port, and an air passage portion communicating between the suction port and the discharge port. A blower that guides air from the suction port to the discharge port inside the airflow path; an active silencing airflow path of a rectangular cylinder provided upstream in the airflow direction of the blower; and at least a reference microphone. An active silencer that silences the inside of the active silencing air passage, the active silencing air passage having a plurality of grooves along the flow direction of air on the inner wall of the active silencing air passage. The plurality of grooves are provided with either one of the depth and the width or both the depth and the width , thereby achieving an intended purpose.

According to the present invention, a suction port for sucking air, an outlet for discharging the air sucked from the suction port, and the air passage portion which communicates the discharge outlet and suction inlet, inside the air passage portion, from the suction port A blower that guides air to the discharge port , an active silencer air path of a rectangular cylindrical body provided on the upstream side in the air flow direction of the blower section, and an active muffler having at least a reference microphone for silencing the active muffler air path A sound deadening unit, wherein the active sound deadening air passage is provided with a plurality of grooves along an air flow direction on an inner wall of the active sound deadening air passage , and the plurality of grooves are provided with a depth and Either one of the widths, or both the depth and the width are different .

  As a result, in a cross section perpendicular to the flow direction of air in the active noise-reducing air passage, the distance between points on the opposing surface is longer at a portion provided with a groove than at other portions, and is not necessarily uniform. Not, in other words, the distance differs depending on the position, and it is possible to suppress the resonance of the standing wave generated in the active silencing air path internal space, so that while maintaining the desired air volume, the noise reduction effect by the airflow and the standing wave The decrease can be suppressed.

The figure which shows the installation state of the range hood of Embodiment 1 of this invention. Diagram showing the schematic configuration of the same range hood Side sectional view centering on the active silencer of the range hood Diagram showing the general configuration of the exhaust part space of the same range hood Side sectional view of the same range hood Sectional view of the active muffler air path of the range hood Sectional view of active muffler air path of range hood according to Embodiment 2 of the present invention Side sectional view of an active silencer mounted on a conventional blower Sectional view of active silencer mounted on conventional blower

The air blower according to the present invention includes a suction port for sucking air, a discharge port for discharging air sucked from the suction port, an air path communicating between the suction port and the discharge port, and a suction port inside the air path. A blower that guides air from the mouth to the outlet , an active silencer of a rectangular cylindrical body provided on the upstream side in the air flow direction of the blower, and a muffler in the active silencer that includes at least a reference microphone. a blower device comprising an active silencer unit, the performing, the active silencer air passage along the inner wall of the active silencer air passage in the flowing direction of air, a plurality of grooves are provided, a plurality of grooves, Either the depth or the width, or both the depth and the width are different .

  As a result, in a cross section perpendicular to the flow direction of air in the active noise-reducing air passage, the distance between points on the opposing surface is longer at a portion provided with a groove than at other portions, and is not necessarily uniform. However, since the distance varies depending on the position and the standing wave generated in the space inside the active noise-reducing air path can be suppressed from resonating, the noise-reducing effect of the active noise-reducing device can be improved.

Further, it is possible to further diversify the distance between a point on each of the opposite faces in capacity dynamic muffler air passage, it can be further enhanced silencing effect.

  Hereinafter, an embodiment of the present invention will be described using a range hood as an example of a blower, to provide an understanding of the present invention. The following embodiment is an example embodying the present invention, and the present invention is not limited thereto. The same parts are denoted by the same reference numerals throughout the drawings.

(Embodiment 1)
As an example of the blower according to the present embodiment, range hood 1 is attached above cooking device 2 as shown in FIG.

  The range hood 1 includes a hood portion 3 disposed so as to cover an upper surface of the cooking device 2, and an exhaust portion 4 formed so as to protrude toward a central upper surface side of the hood portion 3. Further, by connecting a duct 5 above the exhaust unit 4 (in the exhaust direction), the exhaust from the exhaust unit 4 can be exhausted, for example, to the outside of the room. In addition, one side surface of the range hood 1 as viewed from the direction of the arrow X in FIG. The operation unit 6 for operating the range hood 1 is disposed on the hood unit 3 on the front side.

  FIG. 2 is a diagram illustrating a schematic configuration of a range hood. A state in which a panel on the front side of the range hood of the exhaust unit 4 is removed for easy understanding.

  As shown in FIG. 2, the range hood 1 includes a rectangular parallelepiped exhaust unit 4 and a hood unit 3 below the exhaust unit 4.

  The exhaust part 4 has a vertically long rectangular parallelepiped shape. The rectangular parallelepiped has a discharge port 8 opening the top surface 7 and a suction port 10 opening a lower surface 9 of the rectangular parallelepiped.

  The suction port 10 communicates with an opening 11 on the cooking appliance side of the hood 3.

  The hood section 3 includes an exhaust-portion-side opening 12 communicating with the suction port 10, a cooking appliance-side opening 11 provided upstream of the exhaust-portion-side opening 12, an exhaust-portion-side opening 12, and the cooking appliance-side. Air to the hood portion 3 constituted by the straightening plate 13 provided between the openings 11 (shown by a two-dot chain line in the drawing) and the inner periphery of the cooking appliance side opening 11 and the outer periphery of the straightening plate 13. And a collection port 14 serving as an intake port for the liquid crystal.

  Further, inside the exhaust part 4, there is an air passage part 15 that communicates the suction port 10 and the discharge port 8. The air path unit 15 includes a sound deadening unit space 17 on the upstream side of the airflow on the lower surface 9 side and a blower unit 18 on the downstream side of the airflow on the top surface 7 side.

  The blower 18 includes a fan 19, a motor (not shown) for driving the fan 19, and a casing 20 that collects air from the fan 19 and sends the air to the outlet 8. That is, the blower unit 18 is located at the upper part in the exhaust unit 4 and exhausts the air in the air passage unit 15 connecting the suction port 10 and the discharge port 8.

  As shown in FIG. 3, the sound deadening section space 17 includes, in the exhaust section 4, a blowing section side end plate 21 provided across the air path section 15 on a side close to the blowing section 18, and a suction port disposed in the suction port 10. The air path portion 15 is partitioned by the mouth-side end face plate 22 and formed.

  An active silencer 25 is provided in the silencer space 17.

  The active noise reduction device 25 includes an active noise reduction air passage 26 and an active noise reduction unit 29 that performs noise reduction inside the active noise reduction air passage 26. The active noise-reducing air path 26 is a tubular body, and is an air path in which air flows from the lower side to the upper side in the drawing, in other words, the height direction.

  The active noise-reducing air passage 26 is defined so as to be surrounded by an inner wall 32, and on the outer side of the inner wall 32, the (side wall 34 that is the inner side of) the side plate 33 of the exhaust unit 4 is located. 1 has a double wall configuration when viewed from the outside. Thus, emission of noise to the outside is suppressed. Further, as shown in FIG. 4, a groove 27 is provided on the inner wall 32 of the active noise-reducing air passage 26 from the inlet-side end plate 22 to the blower-side end plate 21. In other words, the groove 27 is provided along the flow direction of the air.

  In the present embodiment, the active noise-reducing air passage 26 is provided such that one side of the cross section has a length of 80 to 90 mm and the width of the groove 27 is about 3 mm.

  Subsequently, the active noise reduction unit 29 sequentially places the error microphone on the inner wall 32 from the suction port 10 side into the air path (in the traveling direction of the noise propagating through the air path from the downstream side to the upstream side). 35, a speaker 36, and a reference microphone 37. Further, the active silencer 29 includes a calculation controller 30 that generates a control signal whose phase and amplitude are adjusted from the signals of the error microphone 35 and the reference microphone 37 and causes the speaker 36 to oscillate. The error microphone 35 and the speaker 36 are moved closer to the suction port 10 from the center in the height direction of the active silencing air passage 26, and the reference microphone 37 is moved closer to the blower 18 which is a noise source from the center. Is installed. Note that the height direction is a direction connecting the outlet 8 and the inlet 10. As a result, the error microphone 35 and the speaker 36 are located farther from the blower 18 than the reference microphone 37. The error microphone 35, the speaker 36, and the reference microphone 37 are connected to the arithmetic and control unit 30.

  The arithmetic and control unit 30 is arranged outside the inner wall 32 of the active silencing air passage 26, that is, in a space independent of the active silencing air passage 26. Thus, by providing the arithmetic and control unit 30 in a space independent of the active noise-reducing air passage 26, it is isolated from smoke, oily smoke, steam, and the like.

  In the above configuration, first, a basic operation of the range hood 1 will be described.

  The operation of the range hood 1 is performed by a user operating the operation unit 6 shown in FIG. When the range hood 1 is operated, a motor constituting the blower 18 is driven, and a fan 19 connected to a rotation shaft of the motor rotates to generate an air flow. That is, as shown by the dotted line in FIG. 5, an airflow 40 is generated from the suction port 10 toward the duct 5 with the collection port 14 as an entrance. The air flow 40 sucked in from the suction port 10 passes through the air path section 15 in the order of the active silencing air path 26 and the blower section 18, and then is discharged from the discharge port 8 to the outside of the exhaust section 4 through the duct 5. .

  That is, the range hood 1 can collect air containing oil smoke and water vapor that rises from below (upstream direction) during cooking as the airflow 40, and then exhaust the air.

  Further, range hood 1 of the present embodiment includes an active noise reduction device 25 in air passage portion 15. In the active noise reduction device 25, noise radiated from the air blower 18 is detected by the reference microphone 37 of the active noise reduction unit 29 in the active noise reduction air passage 26. The noise detected by the reference microphone 37 is transmitted to the arithmetic and control unit 30 as a noise signal. The arithmetic and control unit 30 estimates the noise when the noise passes near the speaker 36 based on the noise signal. Then, the arithmetic and control unit 30 generates an audio signal having an opposite phase to the predicted noise and transmits the generated audio signal to the speaker 36. Since the speaker 36 emits a sound based on the audio signal, noise radiated from the blowing unit 18 due to the blowing can be reduced. Then, the noise radiated from the collection port 14 is reduced. The noise passing through the position of the speaker 36 is detected by the error microphone 35 and transmitted to the arithmetic and control unit 30. Although it is not essential to provide the error microphone 35, the arithmetic and control unit 30 can further improve the noise reduction performance by generating a sound signal based on the noise detected by the error microphone 35 as a correction signal. it can.

  In the present embodiment, as shown in FIG. 6, by providing the groove 27 on the inner wall 32 of the active silencing air passage 26, at least the groove 27 is formed in a cross section perpendicular to the air flow direction in the active silencing air passage 26. The facing surface has a longer distance than other surfaces that do not face the groove 27, and the distance 41 between points on the surface in the same cross section is not necessarily uniform, and the distance 41 varies depending on the position. That is, the distance 41a at a certain point with respect to one surface and the distance 41b at a different point have different lengths. Thereby, it is possible to suppress the standing wave generated in the active noise-reducing air passage 26 from resonating. Therefore, resonance in the active noise-reducing air passage 26 can be suppressed, and noise can be accurately detected, so that the noise-reducing effect of the active noise-reducing device can be improved. In FIG. 6, the distances 41 a and 41 b are given using “a” and “b” in order to distinguish distances at different points in the distance 41 in the cross section of the active noise reduction air passage 26. is there.

  As described above, by providing the groove 27 in the inner wall 32 of the active silencing air passage 26, the range hood 1 with high silencing performance can be realized.

(Embodiment 2)
Next, a range hood according to the second embodiment will be described with reference to FIG.

  In the present embodiment, the groove 27 provided on the inner wall 32 of the active noise-reducing air passage 26 is provided asymmetrically on the surface where the depth or width is opposed. That is, the groove 27f is provided such that the depth and width of the groove 27f closest to the surface facing the groove 27e are different from both the depth and width of the groove 27e. That is, the groove 27e provided on the surface 32e provided with the reference microphone 37 and the groove 27f provided on the surface 32f opposite to the surface 32e have different widths and depths from each other. The central axis 42e of the groove 27e (the direction in which the groove extends) and the central axis 42f of the groove 27f (the direction in which the groove extends) are shifted so as not to face each other. The fact that the central axis 42e and the central axis 42f do not face each other means a state in which the distances from the central axis 43 passing through the central axis of the reference microphone 37 are different from each other in the cross-sectional view of the active noise reduction air path in FIG.

  In the present embodiment, both the depth and the width are different, but either one may be different.

  Thereby, in the cross section perpendicular to the flow direction of the air in the active noise reduction air passage 26, the distance 41 between the points on the opposing surfaces can be further diversified. Since the depths of the groove 27e and the groove 27f are different, the distance 41b and the distance 41c are different lengths because the depths of the groove 27e and the groove 27f are different when comparing the distance 41b and the distance 41c where one influence of the groove is included. It will be. Further, since the distance 41d has two influences of the groove, the distance 41d has a different length from the distance 41a, the distance 41b, and the distance 41c. As a result, the occurrence of resonance in the active silencing air passage 26 can be further suppressed, so that the silencing effect can be further enhanced.

As described above, by changing the depth and width of the groove 27 provided on the inner wall 32 in the active noise-reducing air passage 26, it is possible to realize the range hood 1 in which the influence of resonance is reduced and high noise-reducing performance is secured. You can do it.
(Modification)
As described above, the silencing technology of the range hood has been described as an example of the blower particularly requiring silencing. However, the present invention does not need to be limited to a range hood, but can be applied to any air blower that generates noise by blowing air, such as an air purifier, a dehumidifier, and a ventilation fan.

  Further, in the present embodiment, one active noise-reducing air path is used, but the number of active noise-reducing air paths may be increased according to the frequency band to be silenced.

  The blower according to the present invention can suppress the resonance in the air path, so that it can be applied to not only a range hood but also a blower that generates noise by blowing, such as an air purifier, a dehumidifier, and a ventilation fan. Can be useful.

DESCRIPTION OF SYMBOLS 1 Range hood 2 Cooking device 3 Hood part 4 Exhaust part 5 Duct 6 Operation part 7 Top surface 8 Discharge port 9 Lower surface 10 Suction port 11 Cooking appliance side opening part 12 Exhaust part side opening part 13 Straightening plate 14 Collection port 15 Wind Road section 17 Silencer space 18 Blower 19 Fan 20 Casing 21 Blower side end plate 22 Suction side end plate 25 Active silencer 26 Active silencer air passage 27 Groove 27e Groove 27f Groove 29 Active silencer 30 Arithmetic controller 32 Inner wall 33 Side plate 34 Inner wall 35 Error microphone 36 Speaker 37 Reference microphone 40 Air flow 41 Distance 41a Distance 41b Distance 41c Distance 41d Distance 42e Center axis 42f Center axis 43 Center axis

Claims (2)

A suction port for inhaling air, a discharge port for discharging air sucked from the suction port, an air path communicating the suction port with the discharge port, and an inside of the air path, from the suction port. A blowing unit that guides air to an outlet , an active silencing air passage of a rectangular cylinder provided on the upstream side in the air flow direction of the blowing unit, and a muffler in the active silencing air passage including at least a reference microphone. An active silencer for performing the air blower,
The active noise-reducing air passage has a plurality of grooves along an air flow direction on an inner wall of the active noise-reducing air passage ,
The air blower , wherein the plurality of grooves have one of a depth and a width, or both the depth and the width are different .   The air blower according to claim 1, wherein the groove is provided on at least a wall surface provided with the reference microphone or a wall surface facing the wall.