JP2017101863A - Ventilation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ventilation device in which a silence effect of an active silencer has been improved.SOLUTION: An upstream side opening part 16 on a first wall surface 22 on which an error microphone 18 is installed out of four wall surfaces 21 for constituting a suction port 2 of an active silencer air passage 6 is made into a so-called bell-mouth shape made of a first curved surface 26 having a curvature smaller than a curvature of a second curved surface 28 at the upstream side opening part 16 on the other wall surface 23. Thereby, a ventilation device is provided in which drop in correlation due to airflow noise is suppressed, and a silence effect has been improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ventilator provided with an active silencer that is arranged in an air passage and silences noise generated during operation.

  In recent years, in a ventilation fan installed in a living room, it is required to reduce noise generated during operation. As one of means for solving such a problem, there is a method of mounting an active silencer having a duct configuration in the air passage.

  Conventionally, as an installation configuration of a microphone in this type of active silencer, there has been a problem that if the microphone picks up noise caused by an air flow, an accurate noise signal cannot be acquired, and the silencing effect is reduced. As one of the means for solving such problems, a microphone is installed by providing a space in the corner, which is a low-speed air current range in the square duct, in order to reduce the influence of the air current in the air passage. (For example, refer to Patent Document 1).

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

  2. Description of the Related Art Conventionally, as an active silencer having a duct structure, an internal original sound reference microphone 102 and a silencer speaker 103 which are sequentially attached at appropriate intervals from the upstream side of the air flow 106 inside a rectangular duct 101 made of a thin steel plate. , An error microphone 104 and an arithmetic controller 105 connected thereto are known.

  In this type of apparatus, the generated sound propagating in the rectangular duct 101 together with the air flow 106 is detected by the reference microphone 102, and the arithmetic controller 105 generates a signal having a phase opposite to that of the original sound. The original sound emitted from the loudspeaker 103 is canceled and muffled, the error microphone 104 monitors the internal sound, and the mute speaker 103 is set so that the output of the error microphone 104 becomes zero by the arithmetic controller 105. It adjusts automatically.

  Here, as shown in FIG. 8, the reference microphone 102 and the error microphone 104 are respectively disposed in a microphone section 107 provided at a corner where the flow velocity is low in the rectangular duct 101, and the microphone section 107 is in communication. The opening 108 communicates with the rectangular duct 101. As a result, noise based on the turbulence of the airflow generated in the duct is not picked up, and the original noise that propagates the airflow can be picked up sufficiently. As a result, it has been expected that the influence of the airflow on the microphone can be reduced and the deterioration of the silencing effect can be suppressed.

Japanese Utility Model Publication No. 5-11198

  However, in the active silencer described in Patent Document 1, when the active silencer is applied to a ventilator that requires a larger air volume, there is no significant difference between the wind speeds at the corners and the center of the square duct. Since the wind speed at the part also increases, it has been found that the microphone picks up noise caused by the airflow and it is difficult to obtain a silencing effect.

  Therefore, the present invention solves the above-described problems, and an object of the present invention is to provide a ventilation device that improves the silencing effect of the active silencing device while ensuring a desired air volume.

  In order to achieve the above object, the present invention provides a suction port for sucking air upstream in the air flow direction, a discharge port for discharging air sucked from the suction port, the suction port and the discharge port. An air passage portion that communicates with the air passage, an air blowing portion that guides air from the suction port to the discharge port inside the air passage portion, and an interior of the air passage and upstream of the air passage portion. A square tube-shaped active silencing air passage having a first wall surface and another wall surface, and an active silencing device configured by a reference microphone, a speaker, and an error microphone to perform silencing in the active silencing air passage, The error microphone is installed on the surface, and the other wall surface is a ventilating device in which the upstream opening of the active silencing air passage is outwardly extended, thereby achieving the intended purpose.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the silencing effect by an airflow can be suppressed, ensuring a desired air volume.

Configuration schematic diagram of ventilation apparatus according to Embodiment 1 of the present invention Side sectional view of a ventilating apparatus according to Embodiment 1 of the present invention. Side sectional view in other composition of the ventilator concerning Embodiment 1 of the present invention. Configuration schematic diagram of ventilation apparatus according to Embodiment 2 of the present invention Side sectional view of a ventilator according to Embodiment 2 of the present invention. The figure which shows the upstream opening part periphery of the active noise-reduction air path of the ventilation apparatus which concerns on Embodiment 2 of this invention. Side sectional view of an active silencer mounted on a conventional ventilator Cross-sectional view of an active silencer mounted on a conventional ventilation device

  The ventilator according to claim 1 of the present invention includes a suction port for sucking air on the upstream side in the air flow direction, a discharge port for discharging air sucked from the suction port, the suction port, and the discharge port. An air passage portion that communicates with the air passage, a blower portion that guides air from the suction port to the discharge port inside the air passage portion, and a first portion provided inside the air passage and upstream of the air passage portion. A square tube-shaped active silencing air passage having one wall surface and another wall surface, and an active silencing device composed of a reference microphone, a speaker, and an error microphone for silencing the active silencing air passage, The error microphone is installed on a wall surface, and the upstream side opening of the active silencing air passage is shaped to spread outwardly on the other wall surface.

  As a result, the pressure loss at the upstream opening is smaller on the other wall surface on which the error microphone is not installed than on the first wall surface on which the error microphone is installed, and the flow rate flowing from the other wall side is increased. In other words, the density of the airflow near the first wall surface where the error microphone is installed is smaller than the density of the airflow near the other wall surface. That is, since the wind speed in the vicinity of the first wall surface where the error microphone is installed is reduced, it is possible to reduce the influence of noise caused by the turbulence that the error microphone receives, and as a result, it is possible to improve the silencing effect.

  In the ventilator according to claim 2 of the present invention, the outwardly opening shape of the upstream opening has a first curved surface and a second curved surface as outwardly extending curved surfaces on the first wall surface and the other wall surfaces, respectively. The curvature of the first curved surface is smaller than the curvature of the second curved surface.

  As a result, since the upstream opening of the wall surface where the error microphone is installed is curved with the first curved surface and the second curved surface, the airflow is smoothly guided into the active silencing air passage, so the airflow around the suction port The generation of vortices can be suppressed. In particular, by reducing the curvature of the first curved surface at the upstream opening of the first wall surface where the error microphone is installed compared to the second curved surface of the other wall surface, the pressure loss at the upstream opening of the other wall surface is reduced. And the flow rate flowing from the first wall surface side where the error microphone is installed is reduced.

  That is, the generation of the vortex of the airflow at the suction port can be suppressed while maintaining the deviation of the airflow density between the first wall surface side where the error microphone is installed and the other wall surface side. As a result, it is possible to reduce the influence of noise caused by the turbulence of the air flow that the error microphone receives, and to improve the silencing effect.

  Moreover, the ventilator concerning Claim 3 of this invention is provided with the convex member which the said upstream opening part protruded in the direction which extends the said wall surface 1st wall surface.

  Thereby, the pressure loss in the upstream opening of the wall surface on which the error microphone is installed increases. That is, the difference between the pressure loss on the first wall surface side and the pressure loss on the other wall surface 23 side increases, and the wind speed in the vicinity of the first wall surface becomes smaller. Furthermore, since the distance from the suction port end to the error microphone becomes longer, it is possible to suppress the vortex of the airflow generated at the suction port from reaching the error microphone. As a result, it is possible to reduce the influence of noise caused by the turbulence of the air flow that the error microphone receives, and to improve the silencing effect.

  In the ventilator according to claim 4 of the present invention, the convex member has a curved surface at the bottom portion on the most upstream side.

As a result, the airflow is smoothly guided into the active silencing air passage, so that the generation of vortex of the airflow around the suction port can be suppressed. As a result, it is possible to reduce the influence of noise caused by the turbulence of the air flow that the error microphone receives, and to improve the silencing effect.
(Embodiment 1)
Hereinafter, the configuration of the ventilation device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram of a ventilation device according to Embodiment 1 of the present invention. In FIG. 1, a part of the outline (front surface and one side surface) of the ventilation device 1 is omitted for understanding. FIG. 2 is a sectional side view of the ventilation device 1 according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the ventilator 1 according to the first embodiment includes a casing having an outer shape that is a substantially rectangular parallelepiped.

  The ventilator 1 includes a suction port 2 and a discharge port 3 provided in the housing. In addition, in the ventilation device 1, an air passage portion 4 that allows the suction port 2 and the discharge port 3 to communicate with each other, and an active silencer air passage 6 as an active silencer device 5 and an air blowing portion 7 in the air passage portion 4. It has.

  The discharge port 3 is located on the most downstream side (upward in FIG. 1) in the flow direction of the airflow in the ventilation device 1 and communicates with the outlet 8 of the blower unit 7.

  In other words, the active silencing air passage 6 is arranged on the upstream side of the ventilation device 1 and the air blowing section 7 is arranged on the downstream side.

  The blower unit 7 includes a circular multi-blade fan 9, a motor (not shown) that rotates the multi-blade fan 9, a casing 10 that encloses the multi-blade fan 9, and a rotation shaft that is the center of rotation of the multi-blade fan 9. 11. The motor (not shown) is coaxial with the rotating shaft 11 and is disposed so as to be embedded in the space inside the blower unit 7. Moreover, the rotating shaft 11 is arrange | positioned orthogonally with respect to the flow direction (from the downward direction of FIG. 1) to the airflow. The inflow port 12 is provided on the substantially circular side surface of the casing 10 and is provided perpendicular to the rotation shaft 11.

  The blower unit 7 sucks air on the upstream side at the inlet 12 that opens in the casing 10 and discharges air from the outlet 8, whereby the air sucked in from the suction port 2 is discharged from the outlet 3 to the outside of the ventilation device 1. To discharge.

  A downstream partition wall 13 of a plate body perpendicular to the airflow direction is disposed on the upstream side of the blower unit 7. The downstream partition wall 13 partitions the air passage portion 4 into an upstream side and a downstream side, but also includes an opening 14 that forms a part of the air passage portion 4.

  An upstream partition wall 15 is arranged at the most upstream (downward in FIG. 1) in the air flow direction of the ventilation device 1. The suction port 2 is provided in the upstream partition wall 15 as an opening for sucking air from the outside of the ventilation device 1.

  The active silencing air passage 6 is provided on the downstream side of the suction port 2 so that the upstream opening 16 of the active silencing air passage 6 and the suction port 2 communicate with each other. Further, the downstream opening 17 of the active silencing air passage 6 is provided in communication with the opening 14 of the downstream partition wall 13. The active silencing air passage 6 has a quadrangular cross-sectional shape perpendicular to the airflow direction.

  Next, the configuration of the active silencing air passage 6 provided with the active silencing device 5 will be described in detail.

  The active silencer 5 includes an error microphone 18, a speaker 19, and a reference microphone 20 in order from the suction port 2 side in the air flow direction of the active silencer air passage 6. In addition, an arithmetic controller (not shown) that generates an audio signal whose phase and amplitude are adjusted from the signal of the reference microphone 20 and oscillates from the speaker 19 is provided.

  The error microphone 18 and the speaker 19 are brought closer to the suction port 2 side from the central portion in the air flow direction of the active silencing air passage 6, and the reference microphone 20 is similarly blown from the central portion as a noise source. Installed close to the side. As a result, the error microphone 18 and the speaker 19 are disposed closer to the suction port 2 than the reference microphone 20.

  As already described, the active silencing air passage 6 has a quadrangular cross-sectional shape. That is, it has a hollow rectangular tube shape surrounded by four wall surfaces 21 and has a substantially square air passage cross section. The length of one side of the square is set to a half wavelength of the maximum silencing frequency from the plane wave condition so that the sound generated by the speaker 19 becomes a plane wave inside the duct at the maximum silencing frequency.

  The reference microphone 20, the error microphone 18, and the speaker 19 are installed on the first wall surface 22 among the four wall surfaces 21.

  As shown in FIG. 2, the upstream opening 16 is formed in the uppermost stream of the four wall surfaces 21 constituting the active silencing air passage 6 in the suction port 2. Here, of the four wall surfaces 21, the other wall surface 23 has the upstream opening 16 of the active silencing air passage 6 as an outwardly extending shape 24 formed of a plane inclined outward toward the upstream side. The outward spreading shape 24 may be a flat surface or a curved surface.

  Further, as shown in FIG. 3, the outwardly extending shape 24 may be a so-called bell mouth shape having curved surfaces capable of collecting air more smoothly than the plane on the four wall surfaces 21. In this case, the curvature of the first curved surface 26 of the upstream opening 16 in the first wall surface 22 to which the error microphone 18 is attached is the first curvature of the upstream opening 16 of the other wall surface 23 which is the other three surfaces. It is assumed that the curvature of the double curved surface 28 is smaller. In addition, it is not essential to provide the outward spreading shape 24 on the first wall surface 22.

  The above is the configuration of the ventilation device 1 according to the present embodiment.

  Then, operation | movement and an effect | action of each part at the time of operation | movement of the ventilation apparatus 1 are demonstrated.

  In the said structure, when the ventilation part 7 operates in the ventilator 1, the airflow from the suction inlet 2 to the discharge outlet 3 will generate | occur | produce. At the same time, noise resulting from the operation of the blower 7 is radiated from the suction port 2 through the active silencing air passage 6.

  Since the active silencing air passage 6 has a function of converting the sound pressure into a plane wave that is uniform in the cross-sectional direction perpendicular to the air flow direction, the sound pressure propagates in one dimension in the air passage. Therefore, in the active silencer 5, the reference microphone 20 detects noise, and transmits the detected noise as a noise signal to an arithmetic controller (not shown).

  The arithmetic control unit first predicts the sound at the position where the error microphone 18 is arranged from the sound detected by the reference microphone 20. The prediction is performed based on the correlation between the reference microphone 20 and the error microphone 18 obtained in advance. Next, an inversion phase audio signal for canceling the predicted sound is generated and generated from the speaker 19 to mute. Furthermore, in order to prevent the sound transmitted to the error microphone 18 from being shifted from the predicted sound and reducing the muffling effect, the sound detected by the error microphone 18 is transmitted to the calculation control unit so that the calculation control unit is correlated. Correct sex. This improves the silencing effect.

  In this mechanism, the higher the correlation between the sound detected by the reference microphone 20 and the sound detected by the error microphone 18, the higher the noise reduction effect. In order to increase this correlation, it is necessary that the same sound as the sound detected by the reference microphone 20 is transmitted to the error microphone 18. However, for example, when a sound that can be heard only by one microphone is generated, the correlation is lowered.

  One of the factors that reduce this correlation is the noise sound of the air current itself and the noise sound of the vortex generated by the turbulence of the air current. When the microphone detects these noises, the correct noise propagating from the blower unit 7 cannot be detected. Therefore, reducing the flow velocity in the vicinity of the microphone and suppressing the generation of vortices are important for obtaining high correlation.

  Next, the curvature of the first curved surface 26 of the upstream opening 16 in the first wall surface 22 to which the error microphone 18 is attached, which is a feature of the present embodiment, is the second curved surface of the other wall surface 23. The effect | action by making it smaller than the curvature of the curved surface 28 is demonstrated using FIG.

  As shown in FIG. 3, the upstream openings 16 of the four wall surfaces 21 constituting the suction port 2 have a substantially bell mouth shape, but the upstream openings in the first wall surface 22 to which the error microphone 18 is attached. Only the curvature of the sixteen first curved surfaces 26 is smaller than the curvature of the upstream opening 16 of the second curved surface 28. For example, the curvature of the first curved surface 26 of the upstream opening 16 in the first wall surface 22 to which the error microphone 18 is attached is about 約 of the curvature of the upstream opening 16 of the other second curved surface 28.

  As a result, the flow rate is partially offset by changing the size of the outwardly spread shape 24 at the suction port, and the larger the size of the spread, the smaller the pressure loss and the easier the flow of air. That is, the inflow amount from the other wall surface 23 side where the curvature of the curved surface in the upstream opening 16 is large is large, and the inflow amount from the first wall surface 22 having a small curvature is small. As a result, the flow velocity of the airflow in the vicinity of the first wall surface 22 to which the error microphone 18 is attached is smaller than that in the vicinity of the other wall surface 23, and the influence of noise caused by the airflow received by the error microphone can be reduced. Further, even when the outwardly extending shape 24 is not provided on the first wall surface 22, since the inflow amount from the other wall surface 23 side is increased by providing the outwardly extending shape 24 on the other wall surface 23, the same effect is achieved. .

  Furthermore, the so-called bell mouth shape provided in the upstream opening 16 of the first wall surface 22 to which the error microphone 18 is attached causes the air flow to smoothly flow into the active silencing air passage 6. The occurrence of turbulence is suppressed. Therefore, the influence of noise caused by the vortex of the airflow received by the error microphone 18 can be suppressed.

  As a result, the error microphone 18 can detect the correct noise propagating from the air blowing unit 7 with almost no influence of noise due to the airflow, and can improve the silencing effect by maintaining high correlation. . Note that the reference microphone 20 is disposed on the downstream side of the air flow in the active silencing air passage 6 and is located in a region where the air flow is sufficiently rectified, so that it is not easily affected by vortex or noise in the suction port 2. Therefore, the reference microphone 20 may be attached to the other wall surface 23.

As described above, the curvature of the first curved surface 26 of the upstream opening 16 in the first wall surface 22 to which the error microphone 18 is attached among the substantially bellmouth shaped curved surfaces in the suction port 2 is the other wall surface. By making the curvature smaller than the curvature of the second curved surface 28 of the upstream opening 16 of 23, the ventilator 1 that ensures a high silencing performance can be realized.
(Embodiment 2)
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and description will be made with reference to FIGS. 4, 5, and 6. FIG. 4 is a schematic configuration diagram of a ventilation device according to Embodiment 2 of the present invention. In FIG. 4, a part of the outline of the ventilation device 1 is omitted for the sake of understanding. FIG. 5 is a side sectional view of a ventilator according to Embodiment 2 of the present invention. FIG. 6 is a view showing the vicinity of the upstream opening 16 of the active silencing air passage according to Embodiment 2 of the present invention.

  As shown in FIG. 4, in the ventilation device 1 according to the second embodiment, the curved surface that can collect air more smoothly than the plane of the upstream side opening 16 of the other wall surface 23 to which the error microphone 18 is not attached. The suction port 2 is provided with a removable convex member 29 projecting in the direction of extending the first wall surface 22 with the error microphone 18 attached to the upstream outside of the air flow in the active silencing air passage 6. I have. Extending the first wall surface 22 can be realized by standing a convex member 29 on the upstream partition wall 15.

  The convex member 29 is a box having a rectangular opening 30. The opening 30 is surrounded by four side walls including a long side and a short side. The side wall 31 includes the long side, the side wall 32 includes the short side, and the bottom 33.

  The length of the long side of the side wall 31 is at least the width of the first wall surface 22, so that the side wall 31 is positioned on the extension of the first wall surface 22 to which the error microphone 18 is attached, and the opening 30 is on the upstream side. It is installed toward the partition wall 15. That is, the first wall surface 22 to which the error microphone 18 of the active silencing air passage 6 is attached by the side wall 31 of the convex member 29 is further extended to the upstream side from the suction port 2.

  With the above configuration, the upstream opening 16 of the other wall surface 23 to which the error microphone 18 is not attached has a so-called bell mouth shape, and the suction port 2 is provided with a convex member 29 that extends the first wall surface 22, thereby The pressure loss on the first wall surface 22 side to which the microphone 18 is attached is larger than the pressure loss on the other wall surface 23 side to which the error microphone 18 is not attached. Therefore, the inflow amount of the airflow from the first wall surface 22 side to which the error microphone 18 is attached can be reduced. As a result, the flow velocity of the airflow in the vicinity of the first wall surface 22 to which the error microphone 18 is attached is smaller than that in the vicinity of the other wall surface 23, and the influence of noise caused by the airflow received by the error microphone can be reduced.

  Furthermore, as shown in FIG. 5, the bottom 33 that is the most upstream portion in the installed state of the convex member 29 has a rounded surface shape that is curved away from the suction port 2. Thereby, generation | occurrence | production of the eddy of the airflow in the bottom part 33 of the convex member 29 can be reduced. In addition, since the first wall surface 22 to which the error microphone 18 of the active silencing air passage 6 is attached is extended to the upstream side by the one side wall 31 of the convex member 29, the length from the error microphone 18 to the bottom 33 which is the most upstream is long. Lengthens. Therefore, the rectification action is likely to work before the airflow reaches the position of the error microphone 18, and the influence of the airflow disturbance that the error microphone 18 receives can be further suppressed.

  Furthermore, as shown in FIG. 6, the side wall 31 facing the active silencing air passage 6 side of the convex member 29 has a height from the bottom 33 that is several millimeters lower than the height of the other side wall 31 and side wall 32. By doing so, a slit-like gap 34 can be provided at the connection portion between the convex member 29 and the first wall surface 22 of the active silencing air passage 6. Thus, the active silencing air passage 6 is in spatial communication with the inside of the convex member 29 at the suction port 2 portion. With this configuration, the convex member 29 can be used for collecting oil when installed in the kitchen, and for collecting condensed water when installed in the bathroom.

  In addition, in order to collect oil and dew condensation water, it is preferable to make the convex member 29 a removable box. However, if it is not necessary to use them for these purposes, a structure may be provided integrally with the upstream partition wall 15 without providing a cavity inside.

  As described above, the upstream opening 16 of the first wall surface 22 to which the error microphone 18 is attached includes the protruding member 29 protruding in the direction in which the first wall surface 22 is extended, and the error microphone 18 is not attached. By making the upstream side opening 16 of the wall surface 23 into a so-called bell mouth shape having a smoother curved surface than a flat surface, it is possible to realize the ventilator 1 that secures a high silencing performance.

  Although the active silencing air passage 6 has been described as having a rectangular tube shape throughout the embodiment, it may be a polygon other than a quadrangle. The first wall surface 22 provided with the error microphone 18 may be a flat surface, and the other wall surface 23 may be a curved surface. In this embodiment, even in this case, a corner is formed at the connection portion between the first wall surface 22 and the other wall surface 23, so that it is included in the rectangular tube shape.

  Further, the active silencer air passage 6 may be formed in parallel by preparing a plurality of cylindrical shapes.

  The ventilator according to the present invention is useful as a ventilator such as a house ventilation fan or a range hood with suppressed noise.

DESCRIPTION OF SYMBOLS 1 Ventilation device 2 Suction port 3 Discharge port 4 Air passage part 5 Active silencer 6 Active silencer air passage 7 Blower part 8 Outlet 9 Multiblade fan 10 Casing 11 Rotating shaft 12 Inlet 13 Downstream partition wall 14 Opening 15 Upstream side Partition wall 16 Upstream side opening 17 Downstream side opening 18 Error microphone 19 Speaker 20 Reference microphone 21 Four wall surfaces 22 First wall surface 23 Other wall surface 24 Outward spreading shape 26 First curved surface 28 Second curved surface 29 Convex member 30 Opening 31 Side wall 32 Side wall 33 Bottom 34 Clearance

Claims (4)

A suction port for sucking air upstream in the air flow direction;
A discharge port for discharging air sucked from the suction port;
An air passage portion communicating the suction port and the discharge port;
A blower unit for guiding air from the suction port to the discharge port inside the air passage unit;
A square tube-shaped active silencing air passage having a first wall surface and another wall surface provided in the air passage and on the upstream side of the air passage portion;
An active muffler comprising a reference microphone, a speaker, and an error microphone for silencing the active muffler air path,
Installing the error microphone on the first wall;
The other wall surface is a ventilating device in which an upstream opening of the active silencing air passage is outwardly expanded. The outwardly spreading shape of the upstream opening is
2. The first curved surface and the second curved surface respectively have a first curved surface and a second curved surface as curved surfaces spreading outwardly, and the curvature of the first curved surface is smaller than the curvature of the second curved surface. Ventilation device. The ventilation apparatus according to claim 1, wherein the upstream opening includes a convex member protruding in a direction extending the first wall surface. The ventilation device according to claim 3, wherein the convex member has a curved surface at a bottom portion on the most upstream side.