JP2019027360A - Air blower - Google Patents

Abstract

To provide an air blower capable of suppressing noise.SOLUTION: An air blower comprises an axial flow impeller 3 and a bell mouth 4, wherein a slit 26 is provided in an overlapping region 25 opposite to a fixation member 24 fixed to the bell mouth 4 and fixing a motor 11, so that a flow passage becomes narrow, and in the overlapping region 25 where interference noise occurs, wind flows in a radial direction vertical to a rotational shaft 12 on a downstream side of the bell mouth 4; then since the flow passage becomes wide, a flow rate of airflow colliding with the fixation member 24 can be made small; and thus interference noise can be prevented from occurring in the fixation member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blower device having a fan motor having a fan mounted therein and having a bell mouth on the indoor side in a shape disposed in a ventilation port provided in a room wall.

  Conventionally, this type of blower has a structure in which a blower is fixed to a frame body and is installed on a wall surface hollowed into a frame shape to efficiently blow air (see, for example, Patent Document 1). ).

  Hereinafter, the blower will be described with reference to FIGS. 4 and 5.

  As shown in FIG. 4, the blower main body 101 has a bell tube 103 formed around a fan 102 by assembling a motor (not shown), a fan 102, and the like to a rectangular tube frame. In such a blower, it is known that the air pressurized by the pressure surface of the blade flows out from the blade tip that is the outer periphery of the blade, and the blade tip vortex is generated, thereby reducing the blowing performance and increasing the noise. Yes. It is known that the shape of the fan 102 and the gap 104 (clearance) between the bell mouth 103 and the fan 102 as shown in FIG. It has been.

  For example, a similar prior document is described in Patent Document 1 below.

JP 2007-040198 A

  However, the blower described in Patent Document 1 is effective for noise on the upstream side of the fan 102, but not effective for noise downstream of the fan 102. There is a support post for fixing the motor downstream of the fan 102, and a fast airflow flowing out of the fan 102 collides with and interferes with the support post. Generally, in order to reduce the interference sound between the airflow and the obstacle, it is conceivable to reduce the flow velocity of the airflow hitting the obstacle. To reduce the flow velocity, if the distance between the fan and the obstacle is increased, The flow velocity decreases with distance attenuation. However, the distance between the fan and the obstacle cannot be increased from the viewpoint of saving the fan space. Therefore, since the noise downstream of the fan 102 cannot be suppressed, there has been a problem that an increase in noise of the blower cannot be suppressed.

  Then, this invention solves the said subject and aims at providing the air blower which suppresses noise.

  And in order to achieve the above-mentioned object, the present invention is fixed to the frame, a fixing member fixed to the frame, a motor including a rotating shaft fixed to the fixing member, and the rotating shaft, In the air blower comprising: a hub provided on the opposite side of the fixing member; a plurality of blades provided so as to stand from the periphery of the hub; and a bell mouth disposed on an outer periphery of the blade; The bell mouth is a blower characterized in that a plurality of slits are provided at the downstream end of the overlapping region facing the fixed member in the direction of the rotation axis, thereby achieving the intended purpose. is there.

  According to the present invention, noise can be suppressed.

1 is a perspective view of a ventilation fan according to Embodiment 1 of the present invention. 1 is a perspective view of a ventilation fan when a blade according to Embodiment 1 of the present invention is removed. Front view of a ventilation fan when blades according to Embodiment 1 of the present invention are removed Schematic diagram of conventional blower Schematic of the vicinity of the fan of a conventional blower

  An air blower according to an embodiment of the present invention includes a frame, a fixing member fixed to the frame, a motor including a rotation shaft fixed to the fixing member, and a rotation shaft fixed to the rotation member and facing the fixing member. In a blower provided with a hub provided on the side, a plurality of blades provided so as to stand up from the periphery of the hub, and a bell mouth disposed on the outer periphery of the blade, the bell mouth faces the fixing member A plurality of slits are provided at the downstream end of the overlapping region.

  With this configuration, conventionally, in the overlapping region where the bell mouth and the fixing member face each other, the flow path area becomes narrow and the flow velocity increases, so that the interference noise increases. However, the bell mouth of the present invention faces the fixing member. By providing a plurality of slits at the downstream end of the overlapping region, the flow path can be widened against the wind flowing in the radial direction downstream of the bell mouth and perpendicular to the rotation axis. The flow rate is the product of the flow channel and the flow velocity, and the flow velocity decreases as the flow channel widens. Therefore, the flow velocity of the airflow flowing downstream of the bell mouth is reduced, and the interference sound generated in the fixing member can be suppressed.

  In the blower according to the embodiment of the present invention, the number of slits is a prime number.

  With this configuration, when the blade and the slit interfere with each other and interference sound is generated, the relative positional relationship between the blade and the slit is different for each blade, so that the interference sound can be prevented from being superimposed and noise can be suppressed.

  Further, in the blower device according to the embodiment of the present invention, the bell mouth includes a plurality of overlapping regions, and the intervals between the plurality of slits provided at the downstream end portions of the respective overlapping regions are provided differently. It is a thing.

  With this configuration, when the blades and slits in each overlapping region interfere with each other to generate an interference sound, the relative positional relationship between the blades and the slits is different for each blade, so that the interference sound is prevented from being superimposed and noise is suppressed. be able to.

  Moreover, the air blower which concerns on embodiment of this invention has the shape of a slit as a notch of a waveform.

  With this configuration, since the slit has a corrugated notch shape, the wind that touches the slit passes through the corrugated notch so that the flow path gradually expands. It can control, can blow efficiently, and can also suppress noise.

  Moreover, as for the air blower which concerns on embodiment of this invention, a waveform is extended so that the rotation direction of a blade | wing may be met.

  Thereby, since the wave is distorted in the flow direction of the airflow, the turbulence of the airflow can be reduced, so that the air can be efficiently blown and noise can be suppressed.

  Hereinafter, an embodiment of the present invention will be described by using a ventilation fan as an example of a blower, and the present invention will be understood. The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention. Moreover, the same number is attached | subjected about the same site | part through all the drawings. Furthermore, in each drawing, the description of the details of each part not directly related to the present invention is omitted.

(Embodiment 1)
FIG. 1 is a perspective view of a ventilating fan according to the present invention in Embodiment 1. FIG.

  As shown in FIG. 1, a ventilation fan 1 according to the present embodiment includes a rectangular tube frame 2 and a fixing member 24, a motor (not shown), an axial flow impeller 3, and a bell mouth 4. . The front panel 5 is provided as an outline of the ventilation fan 1. Here, the front panel 5 includes a bell mouth 4 surrounding a central opening and a flat portion 7 around the bell mouth 4. The flat surface portion 7 has a substantially flat shape so as not to disturb the flow along the front panel 5. The bell mouth 4 is formed of a curved surface that smoothly narrows from the flat portion 7 toward the central opening. The axial flow impeller 3 includes a plurality of (five in the present embodiment) blades 8 and a hub 9 to which the blades 8 are attached.

  FIG. 2 shows a perspective view when the axial flow impeller 3 is removed, and FIG. 3 is a front view when the axial flow impeller 3 is removed.

  The motor 11 is attached to the center of the fixing member 24, and the fixing member 24 has two supporting columns 27 extending on a pair of opposing surfaces of the frame 2, and the supporting columns 27 are attached to the frame 2. Yes.

As shown in FIG. 2, the fixing member 24 has a substantially H shape, and the four struts 27 of the fixing member 24 are formed on a pair of opposing surfaces of the inner surface of the rectangular tube of the frame body 2. The support columns 27 are fixed as a set of two each. The fixing method is not shown, but a metal fitting provided at the end of the column 27 is fixed to the inner surface of the frame body 24 by screwing. A pair of two columns is connected to the end of the column 27 fixed to the inner surface of the rectangular tube 2 of the frame 2.
Further, as shown in FIG. 2, the motor 11 is arranged at the center of the fixing member 24. The motor 11 is disposed so as to face the opening on the front side of the bell mouth 4.

  According to such a configuration, the axial-flow impeller 3 rotated by the motor 11 sends air in the direction of the blowing direction 10. And since the bellmouth 4 sends out air smoothly from the suction side to the blowing side, it contributes to the improvement of the ventilation efficiency of the ventilation fan 1.

  As shown in FIG. 2, the bell mouth 4 has an opening in the center, and the bell mouth 4 has a shape in which the diameter in a plane perpendicular to the rotation shaft 12 becomes smaller from the suction side to the blow side. In other words, the diameter of the bell mouth 4 is the smallest diameter at the most downstream position of the bell mouth 4. A linear portion 16 is provided on the downstream side of the bell mouth 4 so as to be parallel to the rotating shaft 12 in order to rectify the airflow to be blown out. If the length of the straight portion 16 is increased toward the downstream side, the flow is rectified and the blowing efficiency can be increased.

  As shown in FIG. 2, the bell mouth 4 is arranged so that the straight portion 16 that is the smallest diameter side of the opening of the bell mouth 4 is adjacent to the fixing member 24 fixed to the frame body 2. ing. As shown in FIGS. 2 and 3, the size of the opening on the side having the smallest diameter of the bell mouth 4 is smaller than the rectangular tube-shaped opening of the frame 2 to which the fixing member 24 is fixed. ing. Therefore, the linear portion 16 that is the opening end of the bell mouth 4 is disposed so as to face the periphery of the rectangular tube-shaped opening of the frame body 2. Further, a part of the linear portion 16 of the bell mouth 4 is disposed so as to face an end portion on the side fixed to the inner surface of the rectangular tube of the frame body 2 in the support column 27 of the fixing member. As shown in FIG. 2 and FIG. 3, a bell arranged so as to face a pair of two columns 27 at the end of the column 27 fixed to the inner surface of the rectangular tube of the frame 2. The straight line portion 16 of the mouse 4 is set as an overlapping region 25.

  As shown in FIGS. 2 and 3, the straight portion 16 of the bell mouth 4 has a cross section perpendicular to the rotating shaft 12 on the side of the column 27 of the fixing member 24 fixed to the inner surface of the rectangular tube of the frame 2. It has the overlap area | region 25 which opposes an edge part. As shown in FIG. 3, the linear portion 16 of the bell mouth 4 has overlapping regions 25 a that respectively face the ends fixed to the inner surface of the rectangular tube of the frame 2 in the two sets of support columns 27 of the fixing member. 25b is provided.

  As shown in FIGS. 2 and 3, the overlapping region 25 of the linear portion 16 of the bell mouth 4 is provided with a notch-like slit 26 (a waveform shape in the present embodiment). The cut-out slits 26 are provided so as to cut out from the end edges of the straight portions 16 of the bell mouth 4, and the adjacent cut-out slits are provided at equal intervals. Therefore, the overlapping region 25 of the straight line portion 16 includes a notch-shaped slit 26 with respect to the wind flowing in the radial direction perpendicular to the rotation axis in the overlapping region 25 of the straight line portion 16, so that a part of the radial direction Since the wind passes through the notched slit 26, the flow path of the straight portion 16 is widened. The flow rate is the product of the flow channel and the flow velocity, and the flow velocity decreases as the flow channel widens. Therefore, the flow velocity of the airflow in the overlapping region 25 is reduced, and the interference sound generated in the fixing member 24 can be suppressed.

  There is a position where the rotating blade 8 and the slit 26 arranged at equal intervals in the overlapping region 25 interfere with each other to generate the maximum interference sound. When a certain blade 8 and a slit 26 arranged at equal intervals in the overlapping region 25 interfere with each other and a maximum interference sound is generated, another blade 8 adjacent to the certain blade 8 faces the overlapping region 25. It may be in the position to do. At this time, since the number of the slits 26 in the overlapping region 25 is a prime number, even when the other blade 8 interferes with the slit 26, the arrangement in which the maximum interference sound is generated is relatively different. Further, it is possible to prevent the interference sound generated by the blade 8 and the slit 26 from facing each other and to suppress the noise. Therefore, the noise generated at the straight portion 16 of the bell mouth 4 can be reduced.

  In addition, the interval between the notched slits provided so as to be cut out from the edge of the straight portion 16 of the bell mouth 4 in each of the two overlapping regions 25a and 25b can be made different. Thereby, when the blade 8 and the slit 26 interfere with each other in the overlapping regions 25a and 25b to generate interference sound, the relative positional relationship between the blade 8 and the slit 26 is different between the overlapping region 25a and the overlapping region 25b. Superimposition of sound can be prevented and noise can be suppressed.

  In addition, the cutout shape of the slit 26 has a waveform shape in which the end edge of the linear portion 16 of the bell mouth 4 is wide and gradually tapers from the end edge toward the upstream direction. Further, the corrugated slit 26 extends along the rotational direction of the blade 8. Thereby, since generation | occurrence | production of turbulence can be suppressed when a flow path expands, it can blow efficiently and can also suppress noise.

  By providing the slit 26 in the overlapping region 25 in this way, the flow velocity of the airflow that collides with the fixing member 24 can be lowered, so that the air can be efficiently blown and the increase in noise can be suppressed.

  INDUSTRIAL APPLICABILITY The blower and the ventilating fan according to the present invention are useful as a technology expected to be used as a blower having an axial fan and a bell mouth structure for home use or office work.

DESCRIPTION OF SYMBOLS 1 Ventilation fan 2 Frame 3 Axial flow impeller 4 Bell mouth 5 Front panel 7 Plane portion 8 Blade 9 Hub 10 Air blowing direction 11 Motor 12 Rotating shaft 16 Linear portion 24 Fixing member 25, 25a, 25b Overlapping area 26 Slit 27 Strut 101 Air blow Main unit 102 Fan 103 Bell mouth 104 Clearance

Claims (5)

A frame,
A fixing member fixed to the frame;
A motor fixed to the fixing member and provided with a rotating shaft;
A hub fixed to the rotating shaft and provided on the opposite side of the fixing member;
A plurality of blades provided to stand from the periphery of the hub;
In a blower device provided with a bell mouth arranged on the outer periphery of the blade,
The bell mouth is provided with a plurality of slits at a downstream end portion of an overlapping region facing the fixing member in the rotation axis direction. The blower according to claim 1, wherein the number of the slits is a prime number. The said bellmouth is provided with the said some overlap area, The space | interval of the said some slit provided in the downstream edge part of each said overlap area differs, The Claim 1 or Claim 2 characterized by the above-mentioned. The blower described in 1. The blower according to any one of claims 1 to 3, wherein the shape of the slit is a wave-shaped notch. The blower according to claim 4, wherein the corrugation extends along the rotation direction of the blades.