JP2014020273A - Blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in a conventional blower that noise having a specific frequency generates according to a kind of a sound source and a place, and noises of different frequencies are heard respectively from an air inflow side and an air outflow side.SOLUTION: An inflow-side resonance silencing mechanism is formed by an inflow-side resonance space 15 formed around an inflow port 8 of a fan portion 6 of the blower 1 while surrounded by a housing 11 and a case 5 of the fan portion 6, and an inflow-side slit hole 16 for communicating the inflow port 8 of the fan portion 6 with the inflow-side resonance space 15, and an outflow-side resonance silencing mechanism is formed by an outflow-side resonance space 17 formed around an outflow port 9 of the fan portion 9 while surrounded by the housing 11 and the case 5 of the fan portion 6, and an outflow-side slit hole 18 for communicating the outflow port 9 of the fan portion 6 with the outflow-side resonance space 17, thus a silencing property of the inflow-side resonance silencing mechanism and a silencing property of the outflow-side resonance silencing mechanism can be matched to the frequencies of the noises, and the noises can be effectively reduced.

Description

  The present invention relates to a fan that is used for a fan that generates an airflow indoors, a facility device that performs ventilation and air conditioning through a duct, and the like.

  Conventionally, this kind of blower is known to be installed at the base of a blower assembly (see, for example, Patent Document 1).

  Hereinafter, the blower will be described with reference to FIG.

  As shown in FIG. 4, in the blower assembly 101, a blower 103 that generates an air flow through the duct 102 is installed inside the base 104. The base 104 has an air inlet 106 formed in the outer casing 105. A centrifugal impeller 107 suitable for applying high pressure to air is connected to a motor 108, and an inlet 109 of the impeller 107 communicates with an air inlet 106 formed in the outer casing 105 of the base 104. The blower 103 includes a housing 110 and a diffuser 111 inside the base 104 in order to establish an air flow from the impeller 107 to the duct 102.

  In the above configuration, when the blower 103 is operated, the motor 108 is driven and the impeller 107 rotates. Due to the pressure increasing action by the rotation of the impeller 107, air is sucked into the base 104 through the air inlet 106, flows to the inlet 109 of the impeller 107, and further passes through the impeller 107, and the air flow passes through the housing 110 and the outlet 112 of the diffuser 111. And flows into the duct 102.

Japanese Patent No. 4756286

  In such a conventional blower, the type and location of the sound source such as wind noise caused by the rotation of the impeller 107, turbulent sound caused by the turbulence of the air flow in the housing, and collision sound caused by the air flow colliding with the diffuser 111 Therefore, noise having a specific frequency is generated, and noise having different frequencies is radiated to the outside from the air inlet 106 side through which air flows in and the duct 102 through which air flows out.

  This invention solves such a conventional subject, and it aims at providing the air blower which can reduce the noise which has a specific frequency on the inflow side and the outflow side of air, respectively.

  In order to achieve this object, the present invention includes a motor and a fan unit including a case that includes a centrifugal impeller that is connected to a rotating shaft of the motor and rotates, and the fan unit is provided at a suction port of the centrifugal impeller. Inflow formed with an inlet facing the motor and an outlet facing the back of the electric motor, with a housing containing the fan part, and surrounded by a casing and a case of the fan part around the inlet of the fan part An inflow side resonance silencer mechanism is formed by the side resonance space, the inflow side slit hole communicating with the inflow side resonance space and the inflow side resonance space of the fan unit, and is surrounded by a casing and a case of the fan unit around the outflow port of the fan unit The outflow side resonance space is formed, and the outflow side resonance silencer mechanism is formed by the outflow side slit hole communicating the outflow side resonance space with the outflow side of the fan unit. To achieve the purpose. .

  ADVANTAGE OF THE INVENTION According to this invention, the air blower which can reduce the noise which has a respectively specific frequency in the inflow side and outflow side of air can be provided.

Side sectional view which shows the air blower of Embodiment 1 of this invention Bottom view of the blower Side cross-sectional view when the casing of the blower is large Side view showing a conventional blower

  According to a first aspect of the present invention, there is provided an air blower including a fan unit including a motor and a case including a centrifugal impeller that is connected to a rotating shaft of the motor and rotates, and the fan unit faces a suction port of the centrifugal impeller. An inflow opening and an outflow opening facing the back of the electric motor are provided, and a housing is provided that encloses the fan section. The housing includes an inflow opening and an outflow opening facing the inflow opening and the outflow opening of the fan section, respectively. An inflow-side resonance silencer mechanism is formed by an inflow-side resonance space formed by being surrounded by a casing and a case of the fan unit around the inflow port, and an inflow-side slit hole communicating the inflow port and the inflow-side resonance space of the fan unit. An outflow side resonance space formed by being surrounded by a casing and a case of the fan unit around the outflow port of the fan unit, and an outflow side slit hole communicating the outflow port and outflow side resonance space of the fan unit To form an outflow side resonance silencer mechanism Having the configuration.

  Thereby, there exists an effect that the noise radiated | emitted from the inflow port and the outflow port of a fan part can be reduced, respectively.

  Further, the silencing characteristics of the inflow side resonance silencing mechanism and the silencing characteristics of the outflow side resonance silencing mechanism may be different.

  As a result, even if noise is radiated from the inlet and outlet of the fan unit at specific frequencies, the noise reduction characteristics can be adapted to the respective frequencies, and the noise can be effectively reduced.

  Moreover, you may make it the structure whose cross section of the case of the fan part in arbitrary planes perpendicular | vertical to a rotating shaft is a concentric circle with a centrifugal impeller.

  As a result, the distance between the centrifugal impeller and the case is uniform over the entire circumference of the centrifugal impeller, so that the air flow flowing out of the centrifugal impeller into the case is uniform over the entire circumference, reducing the turbulence of the air flow and reducing noise. There exists an effect that generation | occurrence | production can be suppressed.

  Moreover, you may make it the structure whose casing is concentric with the case of a fan part.

  Thereby, since the inflow side resonance space and the outflow side resonance space formed between the case of the fan part and the casing each have a uniform shape on the entire circumference, it is possible to mute the main frequency of noise on the entire circumference, There is an effect that noise can be effectively reduced.

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

(Embodiment 1)
As shown in FIGS. 1 and 2, the blower device 1 includes a fan unit 6 including a case 5 that encloses an electric motor 2 and a turbofan-shaped centrifugal impeller 4 that is connected to a rotating shaft 3 of the electric motor 2 and rotates. The fan unit 6 includes an inlet 8 facing the suction port 7 of the centrifugal impeller 4 and an outlet 9 facing the back of the electric motor 2.

  As shown in FIG. 2, the case 5 of the fan unit 6 has a circular cross-section in an arbitrary plane perpendicular to the rotation shaft 3 concentric with the centrifugal impeller 4, and the inlet 8 side of the fan unit 6 is the centrifugal impeller 4 side. It has a substantially conical shape that conforms to the shape, and the outlet 9 side of the fan portion 6 has a substantially conical shape that is smoothly connected to the outlet 9.

  The section of the fan unit 6 in an arbitrary plane perpendicular to the rotating shaft 3 of the case 5 is a concentric circle with the centrifugal impeller 4, so that the distance between the centrifugal impeller 4 and the case 5 is the entire circumference of the centrifugal impeller 4. It becomes uniform, the air flow 10 flowing out from the centrifugal impeller 4 to the case 5 becomes uniform over the entire circumference, the disturbance of the air flow 10 is reduced, and the generation of noise can be suppressed.

  The fan unit 6 is disposed in the housing 11. The casing 11 has a cylindrical shape that is concentric with the case 5 of the fan unit 6, and the outer shape thereof is the same as that of the fan unit 6. The casing 11 has an inflow opening 12 facing the inlet 8 and the outlet 9 of the fan unit 6, respectively. The outflow opening 13 is connected to the duct 14.

  An inflow side resonance space 15 surrounded by the casing 11 and the case 5 of the fan unit 6 is formed around the inlet 8 of the fan unit 6, and the casing 11 is formed around the inlet 8 of the fan unit 6. An inflow side slit hole 16 is formed by a gap between the fan portion 6 and the fan portion 6. The inflow side slit hole 16 communicates the inlet 8 of the fan unit 6 with the inflow side resonance space 15 to form an inflow side resonance silencer mechanism.

  Similarly to the inflow port 8 side of the fan unit 6, the outflow side resonance space 17 formed by being surrounded by the casing 11 and the case 5 of the fan unit 6 at the outflow port 9 of the fan unit 6, and the outflow port of the fan unit 6 9 and the outflow side slit 18 that communicates with the outflow side resonance space 17 form an outflow side resonance silencer mechanism.

  According to such a configuration, as shown in FIG. 1, when the centrifugal impeller 4 is rotated by applying a driving force from the electric motor 2, the air flow 10 flows between the inflow opening 12 of the housing 11 and the flow of the fan unit 6. The air is passed through the inlet 8 sequentially to the suction port 7 of the centrifugal impeller 4, and the pressure is increased by the centrifugal impeller 4 and blown out to the case 5 of the fan unit 6. Is discharged from the outlet 9 of the fan unit 6 to the duct 14 through the outlet opening 13 of the housing 11 while being converted into static pressure.

  At this time, various noises such as rotational noise of the centrifugal impeller 4 and turbulent noise generated inside the case 5 are generated, and the sound waves are respectively transmitted through the inlet 8 and the outlet 9 of the fan unit 6. 11 from the inflow opening 12 and the outflow opening 13.

  In the inflow opening 12 of the housing 11, a part of the sound wave of noise enters the inflow side resonance space 15 from the inflow side slit hole 16, but the resonance type silencing structure is formed by the inflow side slit hole 16 and the inflow side resonance space 15. Therefore, a part of the sound wave having a frequency that coincides with the resonance frequency of the resonance type silencing structure is silenced among the sound waves of the incident noise, and noise emitted to the outside from the inflow opening 12 of the housing 11 is reduced. Can be reduced.

  Similarly, a part of the sound wave of noise enters the outflow side resonance space 17 from the outflow side slit hole 18 on the outflow opening 13 side of the housing 11, but the outflow side slit hole 18 and the outflow side resonance space 17 are resonant. Since the sound deadening structure is formed, a part of the sound wave of the incident noise sound wave having the same frequency as the resonance frequency of the resonance type sound deadening structure is muted and emitted to the duct 14 from the outflow opening 13 of the housing 11. Noise can be reduced.

  Here, when there are a plurality of, for example, two types of frequencies to be silenced, the silencer characteristics of the inflow side resonance silencer mechanism and the silencer characteristics of the outflow side resonance silencer mechanism may be different.

  That is, when noise is radiated from the inflow port 8 and the outflow port 9 of the fan unit 6 at specific frequencies, the width of the inflow side slit hole 16 and the outflow side slit hole 18, the inflow side resonance space 15, and the outflow side resonance. The volume of the space 17 can be adjusted to change the silencing characteristics of the inflow side resonance silencing mechanism and the silencing characteristics of the outflow side resonance silencing mechanism.

  Thus, noise can be effectively reduced by adapting the silencing characteristics of the inflow side resonance silencing mechanism and the silencing characteristics of the outflow side resonance silencing mechanism to the respective noise frequencies.

  Here, since the housing 11 has a cylindrical shape concentric with the case 5 of the fan unit 6, the inflow side resonance space 15 and the outflow side resonance space 17 formed between the case 5 of the fan unit 6 and the housing 11 are formed. Since each has a uniform shape on the entire circumference, it is possible to mute the main frequency of noise on the entire circumference and effectively reduce the noise.

  In the present embodiment, the outer shape is made equal to the fan unit 6 in order to reduce the size of the housing 11, but as shown in FIG. 3, even when the outer shape of the housing 11 is larger than the outer shape of the fan unit 6, The same effect can be obtained if the partition wall 19 that partitions the inflow side resonance space 15 and the outflow side resonance space 17 is provided. The partition wall 19 may be provided in each of the inflow side resonance space 15 and the outflow side resonance space 17. Furthermore, since the volume of the inflow side resonance space 15 and the outflow side resonance space 17 can be changed by changing the position of the partition wall 19, the frequency matching range in which noise can be silenced can be expanded. For example, when it is desired to mute relatively high-frequency noise on the inflow side, the partition wall 19 may be arranged so that the volume of the inflow-side resonance space 15 is small. When it is desired to mute relatively low-frequency noise, the inflow-side resonance space is sufficient. What is necessary is just to arrange | position the partition 19 so that the volume of 15 may become large.

  If the diffuser for guiding the air flow from the centrifugal impeller 4 to the outlet 9 is provided on the outlet 9 side of the fan unit 6, the efficiency of the centrifugal impeller 4 is improved, thereby reducing the rotational speed and rotating noise. It is even better because turbulent noise generated inside the case 5 can be suppressed.

  Further, the inflow side slit hole 16 and the inflow side resonance space 15 are divided in the circumferential direction due to some restrictions, the volume of the inflow side resonance space 15 is not uniform in the circumferential direction, or the inside of the inflow side resonance space 15 is inside. Even if parts are arranged, the effect is inferior if the resonance silencer mechanism is formed, but the same effect can be obtained.

  For example, in the present embodiment, the case is described in which the casing 11 is a cylinder. However, in the case of a rectangular tube, the inflow side resonance space 15 is divided in the circumferential direction, or the volume of the inflow side resonance space 15 is not uniform in the circumferential direction. However, since a resonance silencer mechanism can be formed, a part of the sound wave having a frequency that matches the resonance frequency can be silenced. The same applies to the resonance silencer mechanism on the outlet 9 side.

  The blower of the present invention is useful as a blower used for a fan that generates an air flow indoors, a facility device that performs ventilation and air conditioning through a duct, and the like.

DESCRIPTION OF SYMBOLS 1 Blower 2 Electric motor 3 Rotating shaft 4 Centrifugal impeller 5 Case 6 Fan part 7 Suction port 8 Inlet 9 Outlet 10 Air flow 11 Case 12 Inflow opening 13 Outflow opening 14 Duct 15 Inflow side resonance space 16 Inlet side slit hole 17 Outflow side resonance space 18 Outflow side slit hole 19 Bulkhead

Claims (4)

A fan unit including a motor and a case containing a centrifugal impeller that is connected to a rotating shaft of the motor and rotates;
The fan part includes an inlet facing the suction port of the centrifugal impeller, and an outlet facing the back of the electric motor,
A housing containing the fan part;
Each of the housings includes an inflow opening and an outflow opening facing the inflow port and the outflow port of the fan part,
An inflow side resonance space formed by the casing and the case of the fan unit surrounded by the case around the inflow port of the fan unit, and an inflow communicating the inflow side and the inflow side resonance space of the fan unit An inflow side resonance silencer mechanism is formed with the side slit hole,
An outflow side resonance space formed by surrounding the casing and the case of the fan unit around the outflow port of the fan unit, and an outflow communicating the outflow port and the outflow side resonance space of the fan unit The air blower which forms an outflow side resonance silencer mechanism with a side slit hole. The air blower according to claim 1, wherein a silencing characteristic of the inflow side resonance silencing mechanism is different from a silencing characteristic of the outflow side resonance silencing mechanism. The blower according to claim 1 or 2, wherein a cross section of the case of the fan unit in an arbitrary plane perpendicular to the rotation axis is a concentric circle with the centrifugal impeller. The air blower according to claim 3, wherein the casing has a cylindrical shape concentric with the case of the fan unit.

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