JP6076286B2 - Axial flow blower, ventilation device and refrigeration cycle device - Google Patents

Description

  The present invention relates to an axial blower used for a refrigeration cycle apparatus (air conditioner), a ventilator, and the like.

  In the axial blower that blows air by rotating the blades around the rotating shaft, the following techniques are known as techniques for reducing noise. For example, in a blower fan in which a blade and a boss part are integrally molded, with respect to a perpendicular line from the chord midpoint, which is the midpoint of the chord connecting the blade leading edge and the blade trailing edge of the blade root, to the rotation axis, The chord centerline, which continuously connects the chord center points in the blade cross section cut by a plane perpendicular to the perpendicular, once retracted from the root of the blade toward the tip of the blade toward the back of the rotation axis and the back in the rotation direction. Then, it is a thing etc. which made it the shape which turned to the front of a rotating shaft and the rotation direction front again with respect to the said perpendicular (for example, patent document 1).

Japanese Patent Laid-Open No. 04-175499 (FIG. 1 on page 4)

  In the above prior art, the shape of the wing is defined by the chord centerline. For this reason, there is a problem in that the dead water area generated by the airflow escaping to the blade outer peripheral side on the blade inner peripheral side cannot be sufficiently suppressed, and the noise cannot be sufficiently reduced.

  The present invention has been made to solve such a problem, and an object thereof is to provide an axial fan or the like with low noise.

  An axial blower according to the present invention has a boss having a boss that rotates about an axial center, and a plurality of blades that are disposed on an outer peripheral portion of the boss and are surrounded by an inner peripheral edge, an outer peripheral edge, a front edge, and a rear edge. An axial blower including a vehicle, wherein a radius of a boss centered on an axial center is Rb and a radius of an outer peripheral edge of a blade is Rt, and a radius Rm1 that satisfies Rb <Rm1 <Rt and a radius Rm2 that satisfies Rb <Rm2 <Rt , The portion where the distance R1 to the axis at the front edge is Rb <R1 <Rm1, and the portion where the distance R2 to the axis at the rear edge is Rb <R2 <Rm2 are As shown in FIG. 1, the curve is configured by a curve that retreats in the counter-rotation direction and is convex in the rotation direction, and a portion where Rm1 <R1 <Rt at the front edge and a portion where Rm2 <R2 <Rt at the trailing edge Forward in the direction of rotation, and It is composed of a convex in the direction of rotation curve.

  According to the axial blower of the present invention, the portion where Rb <R1 <Rm1 at the front edge and the portion where Rb <R2 <Rm2 at the rear edge are retreated in the counter-rotation direction toward the outer peripheral side, respectively. By being configured with a convex curve, the airflow flowing in from the front edge can be maintained in the inner circumferential direction and the airflow can be prevented from escaping to the outer peripheral side, and the occurrence of dead water areas can be suppressed. . Further, the portion where Rm1 <R <Rt at the front edge and the portion where Rm2 <R2 <Rt at the rear edge are respectively formed by curves that advance in the rotational direction toward the outer peripheral side and are convex in the counter-rotating direction. As a result, the shape of the intersection between the outer peripheral edge and the leading edge of the blade can be sharpened, and the resistance of the airflow flowing into the blade can be reduced, so that the flow on the outer peripheral side with a high flow velocity can be stabilized. For this reason, noise can be reduced.

It is a perspective view of the impeller 1 of the axial-flow fan which concerns on Embodiment 1 of this invention. It is a front view of the impeller 1 of the axial-flow fan which concerns on Embodiment 1 of this invention. It is a figure which shows the flow of the air in the impeller 1 of the conventional axial blower. It is a figure which shows the flow of the air in the impeller 1 of the axial-flow fan which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the value of (Rm-Rb) / (Rt-Rb), and a noise difference. It is a figure which shows the dimension of L1 and L2 which concern on the axial-flow fan of Embodiment 2. FIG. It is a figure which shows the impeller 1 of the axial-flow fan which concerns on Embodiment 3 of this invention. It is a figure showing the structural example of the refrigerating-cycle apparatus which concerns on Embodiment 4 of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Here, with respect to the reference numerals, those given the same reference numerals in FIGS. 1 to 7 are the same or equivalent, and this is common throughout the entire specification. In addition, in each drawing, a reference numeral relating to a plurality of wings is attached to only one representative. Further, in the embodiment and each figure for carrying out the invention, a case where the number of blades is three is shown as an example, but the effect of the present invention can be obtained even when the number of blades is not three.

Embodiment 1 FIG.
1 and 2 are diagrams for explaining an axial blower according to Embodiment 1 of the present invention. Specifically, FIG. 1 is a perspective view of an impeller 1 of an axial blower according to Embodiment 1 of the present invention. FIG. 2 is a front view of the impeller 1 of the axial blower according to Embodiment 1 of the present invention. As shown in FIGS. 1 and 2, the impeller 1 of the axial-flow fan according to the first embodiment of the present invention includes a boss 2 that rotates around an axis and a plurality of sheets disposed on the outer periphery of the boss 2. It is comprised by the wing | blade 3 of this. The wing 3 is surrounded by an inner peripheral edge 31, an outer peripheral edge 32, a front edge 33 and a rear edge 34.

  As shown in FIG. 2, the radius of the boss 2 is Rb with the axis as the center, the radius of the outer peripheral edge 32 of the blade 3 is Rt, and the radius Rm1 that satisfies Rb <Rm1 <Rt and the radius Rm2 that satisfies Rb <Rm2 <Rt. Define At this time, in the portion where the distance R1 to the axial center at the front edge 33 is Rb <R1 <Rm1, and in the portion where the distance R2 from the axial center to the rear edge 34 is Rb <R2 <Rm2, respectively, It is composed of a curve that retreats in the rotation direction and is convex in the rotation direction. In addition, the leading edge is formed in Rm1 <R <Rt, and the trailing edge in Rm2 <R2 <Rt is formed of a curve that advances in the rotational direction toward the outer peripheral side and is convex in the counter-rotating direction.

  FIG. 3 is a diagram showing the shape of the impeller 1 of the conventional axial fan and the air flow. Moreover, FIG. 4 is a figure which shows the flow of the air in the impeller 1 of the axial-flow fan which concerns on Embodiment 1 of this invention. Next, the effect obtained by the structure of the impeller 1 shown in FIG.1 and FIG.2 is demonstrated using FIG.3 and FIG.4. As shown in FIG. 3, in the conventional axial fan, the air flow escapes to the outer peripheral side of the blade due to the influence of the boundary layer developed on the wall surface of the boss and the influence of the centrifugal force due to the rotation of the impeller. As a result, a dead water area was created, which increased noise.

  On the other hand, as shown in FIG. 4, in the axial flow fan according to Embodiment 1 of the present invention, in the blade 3 of the impeller 1, the leading edge 33 recedes in the counter-rotating direction toward the outer peripheral side with Rb <R1 <Rm1. And it is the curve which becomes convex in the rotation direction. For this reason, the airflow flowing in from the front edge 33 is maintained in the inner circumferential direction, and the airflow can be prevented from escaping to the outer circumferential side, and the occurrence of a dead water area on the downstream side of the air in the blade 3 can be suppressed. Further, Rb <R2 <Rm2, and the trailing edge 34 is a curve that recedes in the counter-rotating direction toward the outer peripheral side and is convex in the rotating direction. For this reason, the wing | blade 3 does not exist in the generation | occurrence | production area | region of a dead water area, The noise generated from the wing | blade 3 resulting from the fluctuation | variation of the flow which arises in a dead water area can be reduced. Furthermore, when Rm1 <R1 <Rt, the leading edge 33 is composed of a curved line that advances forward in the rotational direction toward the outer peripheral side when Rm2 <R2 <Rt and is convex in the counter-rotating direction. By making the shape of the intersection of the outer peripheral edge 32 and the leading edge 33 of the blade 3 sharp, the resistance of the airflow flowing into the blade 3 can be reduced. For this reason, the flow of the outer peripheral side with a high flow velocity can be stabilized. With the above effects, the axial flow fan can be reduced in noise.

Embodiment 2. FIG.
Noise reduction can be realized by the impeller 1 of the axial-flow fan configured as in the first embodiment. In the present embodiment, a configuration for realizing further noise reduction will be examined.

  As with the impeller 1 described in the first embodiment, the impeller 1 of the axial blower according to the second embodiment of the present invention is disposed on the boss 2 that rotates around the axis and the outer periphery of the boss 2. The plurality of wings 3 are configured. The wing 3 is surrounded by an inner peripheral edge 31, an outer peripheral edge 32, a front edge 33 and a rear edge 34. When the radius of the boss 2 is Rb, the radius of the outer peripheral edge 32 of the blade 3 is Rt, and the radius Rm1 that satisfies Rb <Rm1 <Rt and the radius Rm2 that satisfies Rb <Rm2 <Rt are defined, the leading edge 33 when Rb <R1 <Rm1. However, when Rb <R2 <Rm2, the trailing edge 34 is configured by a curve that recedes in the counter-rotating direction toward the outer peripheral side and is convex in the rotating direction. In addition, the leading edge 33 is configured with Rm1 <R1 <Rt, and the trailing edge 34 with Rm2 <R2 <Rt is formed of a curve that advances in the rotational direction toward the outer peripheral side and is convex in the counter-rotating direction. Furthermore, when the impeller 1 of the axial-flow fan according to the present embodiment is represented as a radius Rm representing Rm1 and Rm2, the radius Rm is 0.25 <(Rm−Rb) / (Rt−Rb) <0. .65 is satisfied.

  FIG. 5 is a graph showing the relationship between the value of (Rm−Rb) / (Rt−Rb) and the noise difference. Next, the effect obtained by the above configuration will be described. Here, the noise difference shown in FIG. 5 is a value obtained by subtracting the noise value of the conventional axial fan from the noise value of the axial fan according to the present invention. FIG. 5 shows the experimental results when Rm1 = Rm2 = Rm. The noise value is measured at a position 1 m on the downstream side in the axial direction of the axial blower. The axial blower used for the measurement has Rt = 125 mm, Rb = 37.5 mm, and the rotation speed is 900 rpm (rotation / min).

  FIG. 6 is a diagram illustrating dimensions of L1 and L2 according to the axial blower of the second embodiment. Here, when changing Rm1 and Rm2, the dimensions of L1 and L2 are fixed, respectively. The dimensions of L1 and L2 are the dimensions shown in FIG. Portions indicated by broken lines of the leading edge 33 and the trailing edge 34 indicate the shapes of the blades of a conventional axial blower.

  FIG. 5 shows that a significant noise reduction effect is obtained in the range of 0.25 <(Rm−Rb) / (Rt−Rb) <0.65. Therefore, as in the present embodiment, the impeller 1 is configured to satisfy 0.25 <(Rm−Rb) / (Rt−Rb) <0.65. As a result, the leading edge 33 in Rb <R1 <Rm1, and the trailing edge 34 in Rb <R2 <Rm2, respectively, are curves that recede in the counter-rotating direction toward the outer peripheral side and are convex in the rotating direction. The airflow flowing in from the front edge 33 is maintained in the inner circumferential direction, so that the airflow can be prevented from escaping to the outer circumferential side, and the effect of suppressing the generation of dead water areas can be maximized, further reducing noise. be able to.

Embodiment 3 FIG.
FIG. 7 is a diagram showing an impeller 1 of an axial blower according to Embodiment 3 of the present invention. As with the impeller 1 described in the first embodiment, the impeller 1 of the axial fan according to the third embodiment of the present invention is disposed on the boss 2 that rotates around the axis and the outer peripheral portion of the boss 2. The plurality of wings 3 are configured. The wing 3 is surrounded by an inner peripheral edge 31, an outer peripheral edge 32, a front edge 33 and a rear edge 34. When the radius of the boss 2 is Rb, the radius of the outer peripheral edge 32 of the blade 3 is Rt, and the radius Rm1 that satisfies Rb <Rm1 <Rt and the radius Rm2 that satisfies Rb <Rm2 <Rt are defined, the leading edge 33 when Rb <R1 <Rm1. However, when Rb <R2 <Rm2, the trailing edge 34 is configured by a curve that recedes in the counter-rotating direction toward the outer peripheral side and is convex in the rotating direction. In addition, the leading edge 33 is configured with Rm1 <R1 <Rt, and the trailing edge 34 with Rm2 <R2 <Rt is formed of a curve that advances in the rotational direction toward the outer peripheral side and is convex in the counter-rotating direction. Furthermore, as shown in FIG. 7B, the impeller 1 of the axial-flow fan of the present embodiment, as shown in FIG. 7A, when the smaller one of Rm1 and Rm2 is Rmm, The blade cross-sectional shape when the distance R from the shaft center is Rb <R <Rmm is configured as an airfoil.

  Next, the effect obtained by the above configuration will be described. In the conventional axial blower, as shown in FIG. 3, due to the influence of the boundary layer developed on the wall surface of the boss 2 and the influence of the centrifugal force due to the rotation of the impeller 1, A dead water area is created to escape to the outer periphery. For this reason, air does not flow along the meridian plane of the blade 3 in the portion where the leading edge 33 satisfies Rb <R1 <Rm1 and the portion where the trailing edge 34 satisfies Rb <R2 <Rm2. Even an airfoil has little effect of suppressing flow separation. However, by adopting the configuration of the axial flow fan according to the third embodiment of the present invention shown in FIG. 7, the portion of the leading edge 33 that satisfies Rb <R1 <Rm1 and the trailing edge 34 of Rb <R2 <Rm2 The airflow also flows relatively well along the meridian surface of the wing 3 even in the portion where For this reason, the separation of the flow can be further suppressed by making the blade cross-sectional shape of the portion where Rb <R <Rmm be an airfoil. For this reason, it is possible to further reduce the noise of the axial blower.

Embodiment 4 FIG.
FIG. 8 is a diagram illustrating a configuration example of a refrigeration cycle apparatus according to Embodiment 4 of the present invention. Here, FIG. 8 shows an air conditioner as the refrigeration cycle apparatus. The air conditioner of FIG. 8 connects an outdoor unit (outdoor unit) 100 and an indoor unit (indoor unit) 200 through a gas refrigerant pipe 300 and a liquid refrigerant pipe 400. The outdoor unit 100 includes a compressor 101, a four-way valve 102, an outdoor heat exchanger 103, an expansion valve 104, and an outdoor blower 105. The indoor unit 200 has an indoor heat exchanger 201.

  The compressor 101 compresses and discharges the sucked refrigerant. Here, although not particularly limited, the capacity of the compressor 101 (the amount of refrigerant sent out per unit time) is changed by arbitrarily changing the operating frequency of the compressor 101 using, for example, an inverter circuit. You may be able to. The four-way valve 102 is, for example, a valve for switching the refrigerant flow between the cooling operation and the heating operation.

  The outdoor heat exchanger 103 performs heat exchange between the refrigerant and air (outdoor air). For example, it functions as an evaporator during heating operation, evaporating and evaporating the refrigerant. Moreover, it functions as a condenser during the cooling operation, and condenses and liquefies the refrigerant. The blower described in Embodiment 1 or 2 described above is used as the outdoor blower 105.

  An expansion valve 104 such as a throttle device (flow rate control means) expands the refrigerant by decompressing it. For example, in the case of an electronic expansion valve or the like, the opening degree is adjusted based on an instruction from a control means (not shown). The indoor heat exchanger 201 performs heat exchange between air to be air-conditioned and a refrigerant, for example. During heating operation, it functions as a condenser and condenses and liquefies the refrigerant. Moreover, it functions as an evaporator during cooling operation, evaporating and evaporating the refrigerant.

  As described above, according to the refrigeration cycle apparatus of the fourth embodiment, by using the axial flow fan described in the first and second embodiments as the outdoor fan 105, noise reduction can be achieved as a whole apparatus. .

  Although the refrigeration cycle apparatus has been described in the above-described fourth embodiment, the axial-flow fan of the first to third embodiments can be used for, for example, a ventilator.

  1 impeller, 2 bosses, 3 blades, 31 inner peripheral edge, 32 outer peripheral edge, 33 front edge, 34 rear edge, 100 outdoor unit, 101 compressor, 102 four-way valve, 103 outdoor heat exchanger, 104 expansion valve, 105 outdoor Blower, 200 indoor unit, 201 indoor heat exchanger, 300 gas refrigerant piping, 400 liquid refrigerant piping.

Claims (5)

A boss that rotates around its axis,
An axial blower comprising an impeller disposed on an outer peripheral portion of the boss and having a plurality of blades surrounded by an inner peripheral edge, an outer peripheral edge, a front edge and a rear edge,
When the radius Rm1 satisfying Rb <Rm1 <Rt and the radius Rm2 satisfying Rb <Rm2 <Rt are defined with Rb being the radius of the boss centered on the axis and Rt being the radius of the outer peripheral edge of the blade,
A portion where the distance R1 to the axis at the front edge is Rb <R1 <Rm1 and a portion where the distance R2 to the axis at the rear edge is Rb <R2 <Rm2 are respectively closer to the outer peripheral side. Consists of a curve that retreats in the anti-rotation direction and is convex in the rotation direction,
The portion where Rm1 <R1 <Rt at the front edge and the portion where Rm2 <R2 <Rt at the rear edge are respectively composed of curves that advance in the rotational direction toward the outer peripheral side and are convex in the counter-rotating direction. An axial blower characterized by being made. The blade has a shape satisfying 0.25 <( Rm1- Rb) / (Rt-Rb) <0.65 and 0.25 <(Rm2-Rb) / (Rt-Rb) <0.65. The axial-flow fan according to claim 1.   The blade is characterized in that the blade cross-sectional shape of the portion where the distance R from the shaft center is Rb <R <Rmm is an airfoil shape, where Rmm is the smaller of Rm1 or Rm2. Or the axial-flow fan of Claim 2.   A ventilation apparatus comprising the axial blower according to any one of claims 1 to 3.   A refrigeration cycle apparatus comprising the axial-flow fan according to any one of claims 1 to 3.

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