WO2020161850A1

WO2020161850A1 - Centrifugal air blower and air conditioner using same

Info

Publication number: WO2020161850A1
Application number: PCT/JP2019/004355
Authority: WO
Inventors: 惇司河野; 拓矢寺本
Original assignee: 三菱電機株式会社
Priority date: 2019-02-07
Filing date: 2019-02-07
Publication date: 2020-08-13
Also published as: EP3922860A1; JP7003301B2; EP3922860A4; CN113439163A; JPWO2020161850A1

Abstract

A centrifugal air blower (100) comprising a main plate (10) which is rotationally driven, an annular side plate (20) which is positioned facing the main plate, and a plurality of blades (30) which are positioned between the main plate and the side plate, wherein: respective cross sections of the plurality of blades, taken along a surface thereof parallel to the main plate, are defined as first cross sections (CS); in the first cross sections, a linear distance between an inner circumferential end (31) and an outer circumferential end (32) of each of the plurality of blades centered on a rotational shaft (RS) of the main plate, is defined as a blade chord distance (Da); and in a surface of an air outlet formed by an outer circumferential edge part of the main plate and an outer circumferential edge part of the side plate, said surface being vertical with respect to the rotational shaft which passes through a middle position (HB) of the width of an aperture in a direction which extends along said rotational shaft, if a first cross section of the outer circumferential end is defined as a middle cross section (MS), the blade chord distance is greatest in a first cross section which is positioned closer to a side plate side than the middle cross section.

Description

Centrifugal blower and air conditioner using the same

The present invention relates to a centrifugal blower that blows air sucked from a side plate in the axial direction of a rotary shaft by changing its direction in the radial direction and an air conditioner using the centrifugal blower.

Conventionally, a centrifugal blower has been proposed in which the blade outer diameter on the main plate side is smaller than the blade outer diameter on the side plate side than the middle of the distance between the main plate and the side plate in the rotation axis direction of the outlet of the centrifugal blower (for example, See Patent Document 1).

JP, 2015-212547, A

Conventionally, a centrifugal blower includes a main plate having a boss connected to a rotation shaft of a motor, a side plate forming a suction air guide wall, and a plurality of blades arranged between the main plate and the side plate. Has a structure in which air is sucked in from the axial direction, and the airflow is radially turned inside and blown out. In a centrifugal blower, the air flow is more likely to be biased toward the main plate than the middle position of the distance between the main plate and the side plate in the rotation axis direction of the outlet of the centrifugal blower during operation, and pressure loss due to high wind speed occurs on the main plate side. Efficiency tends to decrease. In particular, the centrifugal blower has a characteristic that the above tendency becomes remarkable when the centrifugal blower is installed in an air passage having a small ventilation resistance. Further, in the centrifugal blower, since the airflow is less likely to flow into the side plate side than the intermediate position of the distance between the main plate and the side plate in the rotation axis direction of the outlet of the centrifugal blower, the work amount of the side plate side with respect to the main plate side is smaller. small. In the centrifugal blower of Patent Document 1, since the blade outer diameter on the side plate side is larger than the blade outer diameter on the main plate side than the intermediate position of the distance between the main plate and the side plate in the rotation axis direction of the outlet of the centrifugal blower, the side plate Although the work on the side relatively increases, it is not sufficient to make the air velocity distribution of the blown air uniform.

The present invention is to solve the above problems, and provides a centrifugal blower in which the air velocity distribution of blown air is uniform, and an air conditioner using the same.

A centrifugal blower according to the present invention includes a main plate that is rotationally driven, an annular side plate that is arranged to face the main plate, and a plurality of blades that are arranged between the main plate and the side plates, and is parallel to the main plate. Each cross section of a plurality of blades defined by different planes is defined as a first cross section, and in the first cross section, the straight line distance between the inner peripheral edge and the outer peripheral edge of each of the plurality of blades around the rotation axis of the main plate Defined as the chordal distance, the outer peripheral edge of the air outlet formed by the outer peripheral edge of the main plate and the outer peripheral edge of the side plate in the plane perpendicular to the rotation axis passing through the intermediate position of the opening width in the direction in which the rotation axis extends. When the first cross section having is defined as the intermediate cross section, the chord distance has the maximum value in the first cross section located on the side plate side of the intermediate cross section.

The centrifugal blower according to the present invention has a first cross section having an outer peripheral end defined as an intermediate cross section in a plane perpendicular to the rotation axis passing through the intermediate position of the opening width in the extending direction of the rotation axis at the blowout port. It has the maximum value of the chord distance in the first cross section at the side plate side position. In a centrifugal blower, the air flow is generally apt to be biased toward the main plate side rather than the side plate side. However, the centrifugal blower increases the chord distance on the side plate side compared to the main plate side, and increases the blade area on the side plate side rather than the main plate side to increase the wind speed on the side plate side, so the air blown out is blown out. It is possible to make the wind velocity distribution uniform.

It is a perspective view of the centrifugal air blower concerning Embodiment 1 of the present invention. It is a side view of the centrifugal air blower concerning Embodiment 1 of the present invention. It is the conceptual diagram which looked at the main plate of the centrifugal fan of FIG. 2, the side plate, and one blade from the side surface. It is the conceptual diagram which looked at the cross section of the blade|wing in the surface parallel to the main plate of the centrifugal fan which concerns on Embodiment 1 of this invention in the rotating shaft direction. FIG. 3 is a diagram showing a relationship between a chord distance between an inner peripheral edge and an outer peripheral edge of a blade and a position of a blade cross section in a cross section parallel to a main plate of a centrifugal blower according to Embodiment 1 of the present invention. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal fan which concerns on Embodiment 2 of this invention. It is a side conceptual diagram of the centrifugal fan which concerns on Embodiment 2 of this invention. It is the figure which showed the relationship between the inlet angle of the blade|wing of the centrifugal fan which concerns on Embodiment 2 of this invention, and the position of the cross section CR. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal blower in the position Pb of FIG.7 and FIG.8. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal blower in the position Pc of FIG. 7 and FIG. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal blower in the position Pd of FIG. 7 and FIG. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal fan which concerns on Embodiment 3 of this invention. It is the figure which showed the relationship between the curvature height of the blade|wing and the position of the cross section CR in the centrifugal fan which concerns on Embodiment 3 of this invention. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal fan which concerns on Embodiment 4 of this invention. It is a side conceptual diagram of the centrifugal fan which concerns on Embodiment 4 of this invention. It is the figure which showed the relationship between the exit angle of the blade|wing of the centrifugal fan which concerns on Embodiment 4 of this invention, and the position of the cross section CR. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal blower in the position Pe of FIG. 15 and FIG. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal blower in the position Pf of FIG. 15 and FIG. It is sectional drawing of the blade|wing in the surface perpendicular|vertical to the rotating shaft of the centrifugal blower in the position Pg of FIG. 15 and FIG. It is sectional drawing of the air conditioner in which the centrifugal fan which concerns on Embodiment 5 of this invention is mounted.

Hereinafter, a centrifugal fan 100 and an air conditioner 200 according to an embodiment of the present invention will be described with reference to the drawings. In the following drawings including FIG. 1, the relative dimensional relationship and shape of each component may be different from the actual one. Further, in the following drawings, the components denoted by the same reference numerals are the same or equivalent, and this is common to all the texts of the specification. In addition, for easy understanding, terms indicating directions (for example, “up”, “down”, “right”, “left”, “front”, “rear”, etc. are used as appropriate. For the sake of convenience of description, such a description is given only, and the arrangement and orientation of the device or parts are not limited.

Embodiment 1.
[Structure of Centrifugal Blower 100]
1 is a perspective view of a centrifugal blower 100 according to Embodiment 1 of the present invention. FIG. 2 is a side view of centrifugal blower 100 according to Embodiment 1 of the present invention. The basic structure of the centrifugal blower 100 will be described with reference to FIGS. 1 and 2. The centrifugal blower 100 is rotationally driven by a motor or the like (not shown), and forcibly blows air outward in the radial direction by the centrifugal force generated by the rotation. The centrifugal blower 100 includes a main plate 10 that is a rotating body, a substantially annular side plate 20 facing the main plate 10, and a plurality of blades 30 provided between the main plate 10 and the side plates 20.

(Main plate 10)
The main plate 10 is a rotating body that rotates around the rotation axis RS. The main plate 10 has a circular shape when projected along the rotation axis RS of the centrifugal blower 100, and the radial center portion of the main plate 10 is formed in a substantially conical shape that rises in a mountain shape toward the side plate 20. There is. That is, the main plate 10 forms an inclined surface from the center side toward the outer peripheral side in a direction away from the suction port 102 described later. The main plate 10 has a boss 12 at the center of the main plate 10, that is, at the top of the mountain-shaped swell. The boss 12 is a portion to which a rotation shaft of a motor (not shown) is fixed, and the rotation shaft of the motor is connected to the boss 12. The main plate 10 is driven to rotate about a rotation axis RS by being driven by a motor (not shown). The rotation axis RS is the rotation axis of the main plate 10 and also the rotation axis of the centrifugal blower 100.

The main plate 10 may be a rotating body having the boss 12, and the shape of the main plate 10 is not limited to a substantially conical shape that is circular as viewed in a projection along the rotation axis RS and rises like a mountain. , Other shapes may be used. For example, the main plate 10 may have a disc shape, or may have a polygonal substantially flat plate shape as viewed in a projection along the rotation axis RS. Further, the main plate 10 is formed such that the radial center part of the main plate 10 rises in a mountain shape, and the radial outward part of the main plate 10, that is, the annular portion around the raised radial center part, It may be formed in a substantially flat plate shape.

(Side plate 20)
The side plate 20 is arranged so as to face the main plate 10. The side plate 20 is a circular ring having a substantially arcuate cross section and forms a suction air guide wall. The side plate 20 is a so-called shroud. The side plate 20 has an annular shape when projected along the rotation axis RS of the centrifugal blower 100, and the side plate 20 rises in a mountain shape from the outer side in the radial direction toward the center side. A suction port 102 is formed in the center of the side plate 20. More specifically, the side plate 20 has an end portion 22 on the inner peripheral edge side that forms a suction port 102 of the centrifugal blower 100, and expands radially inward so that the diameter increases as the suction port 102 approaches the main plate 10. It is formed in a curved shape. The side plate outer peripheral edge portion 24 forming the outer peripheral edge of the side plate 20 formed in an annular shape has the largest diameter in the constituent portion of the side plate 20 and is arranged at the position closest to the main plate 10. The outer diameter OS of the side plate 20 is larger than the outer diameter OM of the main plate 10. The centrifugal blower 100 is not limited to the configuration in which the outer diameter OS of the side plate 20 is larger than the outer diameter OM of the main plate 10, and the outer diameter OS of the side plate 20 is equal to the outer diameter OM of the main plate 10. Alternatively, it may be smaller than the outer diameter OM of the main plate 10. The side plate 20 maintains the positional relationship between the tips of the blades 30 by connecting the blades 30 and reinforces the strength of the blades 30.

The main plate 10 and the side plate 20 are arranged at intervals in the extending direction of the rotation axis RS. In the centrifugal blower 100, the side plate outer peripheral edge portion 24 of the side plate 20 and the main plate outer peripheral edge portion 14 of the main plate 10 form an outlet 104 between the side plate outer peripheral edge portion 24 and the main plate outer peripheral edge portion 14. The side plate outer peripheral edge portion 24 is an outer peripheral end portion in the radial direction of the side plate 20, and constitutes an outer peripheral edge of the side plate 20. The main plate outer peripheral edge portion 14 is an outer peripheral end portion in the radial direction of the main plate 10 and constitutes an outer peripheral edge of the main plate 10. The blowout port 104 is an opening through which the air sucked into the centrifugal blower 100 from the suction port 102 by the rotation of the centrifugal blower 100 is discharged.

(Wing 30)
The blades 30 rotate together with the main plate 10 while the main plate 10 is rotating, and generate an airflow from the center of the main plate 10 toward the outer peripheral side. The blades 30 are arranged between the main plate 10 and the side plates 20. Each of the plurality of blades 30 has one end side joined to the main plate 10 and the other end side joined to the side plate 20 in the axial direction of the rotation axis RS of the centrifugal blower 100. The plurality of blades 30 are arranged on the circumference around the rotation axis RS, and each blade 30 is arranged at a predetermined interval in the circumferential direction of the main plate 10. The blades 30 are formed so as to extend rearward with respect to the rotation direction R of the main plate 10.

All of the plurality of blades 30 are formed so that the inner peripheral end 31 is closer to the rotation axis RS than the outer peripheral end 32. The inner peripheral edge 31 is the leading edge of the blade 30, and the outer peripheral edge 32 is the trailing edge of the blade 30. Each inner peripheral end 31 of the plurality of blades 30 is located at a predetermined distance from the rotation axis RS, and each outer peripheral end 32 is located near the main plate outer peripheral edge portion 14 and the side plate outer peripheral edge portion 24. doing. An imaginary extension line of a chord line that is a straight line connecting the inner peripheral end 31 and the outer peripheral end 32 of each blade 30 extends so as not to pass through the rotation axis RS. That is, the inner peripheral end 31 is located in front of the imaginary line in the radial direction connecting the rotation axis RS and the outer peripheral end 32 in the rotation direction R.

The blade outer surface 30a, which is the surface farther from the rotation axis RS, is located farther from the rotation axis RS as it goes rearward in the rotation direction R. In addition, the blade inner surface 30b, which is the surface closer to the rotation axis RS, is at a position further away from the rotation axis RS in the rearward direction of the rotation direction R, with a predetermined distance from the blade outer surface 30a. The thickness of the blades 30 corresponding to the predetermined interval gradually decreases from the center side toward the inner peripheral end 31 and the outer peripheral end 32. That is, the blade 30 has a cross section in a plane perpendicular to the rotation axis RS that approximates a general blade shape.

As shown in FIG. 2, the centrifugal blower 100 has a blade outer diameter OW in the range AS between the side plate 20 and the intermediate position HB of the opening width of the outlet 104 in the direction of the rotation axis RS, as compared with the intermediate position HB. Is large. Further, in the centrifugal blower 100, the size of the blade outer diameter OW is smaller in the range AM between the intermediate position HB of the opening width of the outlet 104 in the direction of the rotation axis RS and the main plate 10 than in the intermediate position HB. .. Then, the centrifugal blower 100 has the maximum value of the blade outer diameter OW on the side plate 20 side from the intermediate position HB of the opening width of the outlet 104 in the rotation axis RS direction, and the blade outer diameter on the main plate 10 side from the intermediate position HB. It has a minimum value of OW. The opening width of the outlet 104 in the rotation axis RS direction is the distance between the main plate outer peripheral edge portion 14 of the main plate 10 and the side plate outer peripheral edge portion 24 of the side plate 20 in the rotational axis RS direction. The blade outer diameter OW is the diameter of the centrifugal blower 100 in the blade 30 portion. In other words, the blade outer diameter OW is the diameter of the rotating circle drawn by the outer peripheral end 32 of the blade 30 by the rotation of the centrifugal blower 100 while the centrifugal blower 100 is operating.

FIG. 3 is a conceptual view of the main plate 10, side plate 20, and one blade 30 of the centrifugal blower 100 of FIG. 2 as viewed from the side. FIG. 4 is a conceptual view of a cross section CS of the blade 30 in a plane parallel to the main plate 10 of the centrifugal blower 100 according to the first embodiment of the present invention as viewed in the rotation axis RS direction. FIG. 5 is a chord distance Da between the inner peripheral edge 31 and the outer peripheral edge 32 of the blade 30 in a section parallel to the main plate 10 of the centrifugal blower 100 according to the first embodiment of the present invention, and a cross section CS of the blade 30. It is a figure showing the relation with the position of. The configuration of the blade 30 will be further described with reference to FIGS. 3 to 5. Note that, in FIG. 3, in order to clarify the configuration of the blade 30, only one blade 30 among the plurality of blades 30 is illustrated, and the illustration of the other blades 30 is omitted. The cross section CS of the blade 30 in the plane parallel to the main plate 10 is defined as the first cross section of the blade 30.

As shown in FIGS. 3 and 4, in each cross section CS of the plurality of blades 30 formed by a plane parallel to the main plate 10, the inner peripheral end 31 and the outer periphery of each of the plurality of blades 30 centered on the rotation axis RS of the main plate 10. The straight line distance to the end 32 is defined as the chord distance Da. Since main plate 10 of centrifugal blower 100 according to Embodiment 1 of the present invention is formed in a substantially conical shape, the surface parallel to main plate 10 is a substantially conical surface. The broken line shown in FIG. 3 illustrates the position of the cross section CS of the blade 30 by the plane parallel to the main plate 10. In addition, in a plane F perpendicular to the rotation axis RS passing through the intermediate position HB of the opening width of the outlet 104 in the direction in which the rotation axis RS extends, the section CS having the outer peripheral end 32 is defined as the intermediate section MS. The centrifugal blower 100 has the maximum value of the chord distance Da in the cross section CS located on the side plate 20 side of the intermediate cross section MS. Then, in the centrifugal blower 100, the chord distance Da between the inner peripheral end 31 and the outer peripheral end 32 of the blade 30 increases from the main plate 10 toward the side plate 20, and the intermediate position between the main plate 10 and the side plate 20. After becoming maximum on the side plate 20 side than HB, it decreases as it goes to the side plate 20.

[Operation of centrifugal blower 100]
In the centrifugal blower 100, when the main plate 10 rotates due to the rotation of the motor connected to the boss 12, the blades 30 fixed to the main plate 10 move in the circumferential direction around the rotation axis RS. Then, when the main plate 10 rotates in the rotation direction R, the air outside the centrifugal blower 100 is sucked into the space surrounded by the main plate 10 and the side plates 20 and the plurality of blades 30 through the suction port 102. Then, in the centrifugal blower 100, the blades 30 rotate together with the main plate 10 so that the air sucked into the space surrounded by the main plate 10 and the plurality of blades 30 is passed between the adjacent blades 30 to obtain the diameter of the main plate 10. Send out to the direction.

[Operational Effects of Centrifugal Blower 100]
In the centrifugal blower 100, the chord distance Da has the maximum value in the cross section CS located closer to the side plate 20 than the intermediate cross section MS. In a centrifugal blower, the air flow is generally more likely to be biased toward the main plate side than the side plate side. However, the centrifugal blower 100 increases the chord distance Da of the blades 30 on the side plate 20 side as compared to the side of the main plate 10 and increases the blade area on the side plate 20 side rather than on the main plate 10 side to increase the wind speed on the side plate 20 side. As a result, the wind velocity distribution of the blown air can be made uniform. Further, in the centrifugal blower 100, the work of the blades 30 on the side plate 20 side is increased by increasing the outer diameter of the blades 30 on the side plate 20 side as compared with the side of the main plate 10 side, and the wind speed is increased. It is possible to further homogenize the wind speed distribution. Then, the centrifugal blower 100 can improve the fan efficiency because the pressure loss due to the high wind speed region due to the uneven flow is reduced by making the distribution of the blown air speed uniform.

Further, in the centrifugal blower 100, the chord distance Da between the inner peripheral end 31 and the outer peripheral end 32 of the blade 30 increases from the main plate 10 toward the side plate 20, and the intermediate position between the main plate 10 and the side plate 20 is increased. After becoming maximum on the side plate 20 side with respect to HB, it decreases toward the side plate 20. The centrifugal blower 100 reduces the chord distance Da in the vicinity of the side plate 20 to reduce the chordal distance Da, thereby causing a wake of the bell mouth connected to the side plate 20 and a leakage flow of air flowing from a gap between the bell mouth and the side plate 20. It is possible to suppress the noise due to the collision of the turbulent air flow caused by the.

Embodiment 2.
FIG. 6 is a cross-sectional view of blades 30 in a plane perpendicular to rotation axis RS of centrifugal blower 100 according to Embodiment 2 of the present invention. FIG. 7 is a conceptual side view of centrifugal fan 100 according to the second embodiment of the present invention. FIG. 8 is a diagram showing the relationship between the inlet angle α of the blade 30 of the centrifugal blower 100 according to the second embodiment of the present invention and the position of the cross section CR. FIG. 9 is a cross-sectional view of the blade 30 in a plane perpendicular to the rotation axis RS of the centrifugal blower 100 at the position Pb in FIGS. 7 and 8. FIG. 10 is a cross-sectional view of the blade 30 in a plane perpendicular to the rotation axis RS of the centrifugal blower 100 at the position Pc shown in FIGS. 7 and 8. FIG. 11 is a cross-sectional view of the blades 30 in a plane perpendicular to the rotation axis RS of the centrifugal blower 100 at the position Pd shown in FIGS. 7 and 8. It should be noted that parts having the same configurations as those of the centrifugal blower 100 shown in FIGS. 1 to 5 are designated by the same reference numerals and the description thereof will be omitted. The centrifugal blower 100 according to the second embodiment further specifies the configuration of the blades 30 in the centrifugal blower 100 according to the first embodiment. Therefore, in the following description, the configuration of the blades 30 of the centrifugal blower 100 according to the second embodiment of the present invention will be mainly described with reference to FIGS. 6 to 11.

(Wing 30)
As shown in FIG. 6, in each cross section CR of the plurality of blades 30 by the plane perpendicular to the rotation axis RS of the main plate 10, the inlet angle α of the blades 30 is defined by the center line CL of the blades 30 and the leading edge portion 35 of the blades 30. It is defined as an angle formed by the tangent line TL1 at the front edge portion 35 of the virtual circle C1 centering on the rotation axis RS passing through. In addition, each cross section CR of the plurality of blades 30 by a plane perpendicular to the rotation axis RS of the main plate 10 is defined as a second cross section of the blade 30. As shown in FIGS. 7 to 11, the inlet angle α of the plurality of blades 30 is set to a position closer to the side plate 20 than the intermediate position Pm between the main plate 10 and the side plate 20 at the leading edge portions 35 of the plurality of blades 30. It has a minimum value in a certain cross section CR. More specifically, as indicated by the inlet angle α1 at the position Pb and the inlet angle α2 at the position Pc, the inlet angle α of the blade 30 decreases from the main plate 10 toward the side plate 20, and the intermediate angle between the main plate 10 and the side plate 20 is reduced. The minimum value is on the side plate 20 side with respect to the position Pm. Then, as indicated by the inlet angle α2 at the position Pc and the inlet angle α3 at the position Pd, the inlet angle α of the blade 30 increases from the position Pc having the minimum inlet angle α2 toward the side plate 20. The intermediate position Pm between the main plate 10 and the side plate 20 in the front edge portion 35 is the middle of the length along the front edge portion 35 between the main plate 10 and the side plate 20.

[Operational Effects of Centrifugal Blower 100]
In the centrifugal blower 100 according to the second embodiment of the present invention, the inlet angle α of the plurality of blades 30 is larger than the intermediate position Pm between the main plate 10 and the side plate 20 at the front edge portion 35 of the plurality of blades 30 than the side plate 20. It has a minimum value in the cross section CR at the side position. In the centrifugal blower 100, by making the inlet angle α of the blade 30 at a position closer to the side plate 20 than the intermediate position Pm, separation of the air flow is suppressed at the front edge portion 35 of the blade 30, so that the wind speed at the side plate 20 side. Can be increased, and the wind speed distribution of the blown air can be made uniform.

Further, in the centrifugal fan 100 according to Embodiment 2 of the present invention, the inlet angle α of the blades 30 increases from the position Pc having the minimum inlet angle α2 toward the side plate 20. Generally, in the vicinity of the side plate 20 of the centrifugal blower, a leak flow of air that flows in through a gap between the side plate 20 and the bell mouth connected to the side plate 20 is likely to occur. Since the leakage flow of air flows in with a swirl component in the rotation direction R of the centrifugal blower 100, the centrifugal blower 100 expands the inlet angle α in the vicinity of the side plate 20 so that the air flow in the leading edge portion 35 of the blade 30 is reduced. The pressure loss due to peeling can be suppressed.

Embodiment 3.
FIG. 12 is a cross-sectional view of blades 30 in a plane perpendicular to rotation axis RS of centrifugal blower 100 according to Embodiment 3 of the present invention. FIG. 13 is a diagram showing the relationship between the warp height H of the blades 30 and the position of the cross section CR in the centrifugal blower 100 according to Embodiment 3 of the present invention. It should be noted that parts having the same configurations as those of the centrifugal blower 100 of FIGS. 1 to 11 are designated by the same reference numerals and the description thereof will be omitted. The centrifugal blower 100 according to the third embodiment further specifies the configuration of the blades 30 in the centrifugal blower 100 according to the first or second embodiment. Therefore, in the following description, the configuration of the blades 30 of the centrifugal blower 100 according to the third embodiment of the present invention will be mainly described with reference to FIGS. 12 and 13.

(Wing 30)
As shown in FIG. 12, in each cross section CR of the plurality of blades 30 in the plane perpendicular to the rotation axis RS, the blade 30 is formed from the straight line SL that connects the leading edge portion 35 and the trailing edge portion 36 of each of the plurality of blades 30. The warp height H of the blade 30 is defined as the distance vertically connected to the center line CL of the blade 30. The warp height H is zero at the leading edge portion 35 of the blade 30 and the trailing edge portion 36 of the blade 30. As shown in FIG. 12, the cross-section CR of the blade 30 is composed of a curve having a large curvature on the outer peripheral side and a curve having a small curvature on the inner peripheral side or a straight line, and the maximum warp height at which the warp height H becomes maximum. The position of Ha is located closer to the rear edge portion 36 than the intermediate position CM, which is the distance connecting the front edge portion 35 and the rear edge portion 36 with a straight line. In the cross section CR of the blade 30, the outer peripheral side is the trailing edge portion 36 side, and the inner peripheral side is the front edge portion 35 side.

As shown in FIG. 13, the warp height H of the blades 30 is at a cross section CR at a position closer to the side plate 20 than the intermediate position Pm between the main plate 10 and the side plate 20 at the front edge portions 35 of the plurality of blades 30. Has a maximum value. That is, the maximum warp height Ha of the entire blade 30 is located closer to the side plate 20 than the intermediate position Pm between the main plate 10 and the side plate 20. More specifically, the warp height H of the blade 30 increases from the main plate 10 toward the side plate 20, and has a maximum value on the side plate 20 side with respect to the intermediate position Pm between the main plate 10 and the side plate 20. The warp height H of the blade 30 decreases from the position of the cross section CR having the maximum value toward the side plate 20.

[Operational Effects of Centrifugal Blower 100]
The warp height H of the blades 30 of the centrifugal blower 100 according to the third embodiment of the present invention has a maximum value in the cross section CR located closer to the side plate 20 than the intermediate position Pm between the main plate 10 and the side plate 20. .. The centrifugal blower 100 increases the warp height H on the side plate 20 side from the intermediate position Pm between the main plate 10 and the side plate 20 and increases the work on the side plate 20 side to increase the wind speed on the side plate 20 side. Further, it is possible to make the wind velocity distribution of the blown air uniform.

Further, in the centrifugal blower 100 according to the third embodiment of the present invention, the warp height H of the blades 30 decreases from the position of the cross section CR having the maximum value toward the side plate 20. In the vicinity of the side plate 20 of the centrifugal blower 100 according to the third embodiment of the present invention, the chord distance Da between the inner peripheral end 31 and the outer peripheral end 32 of the blade 30 becomes small, so that the air flow is easily separated. Therefore, centrifugal blower 100 according to Embodiment 3 of the present invention can suppress separation of the air flow by reducing warpage height H.

Fourth Embodiment
FIG. 14 is a cross-sectional view of blades 30 in a plane perpendicular to rotation axis RS of centrifugal blower 100 according to the fourth embodiment of the present invention. FIG. 15 is a conceptual side view of the centrifugal blower 100 according to Embodiment 4 of the present invention. FIG. 16 is a diagram showing the relationship between the outlet angle β of the blades 30 of the centrifugal blower 100 according to the fourth embodiment of the present invention and the position of the cross section CR. FIG. 17 is a cross-sectional view of the blade 30 in a plane perpendicular to the rotation axis RS of the centrifugal blower 100 at the position Pe of FIGS. 15 and 16. FIG. 18 is a cross-sectional view of the blades 30 in a plane perpendicular to the rotation axis RS of the centrifugal blower 100 at the position Pf shown in FIGS. 15 and 16. FIG. 19 is a cross-sectional view of the blade 30 in a plane perpendicular to the rotation axis RS of the centrifugal blower 100 at the position Pg shown in FIGS. 15 and 16. It should be noted that parts having the same configurations as those of the centrifugal blower 100 of FIGS. 1 to 13 are designated by the same reference numerals and the description thereof will be omitted. The centrifugal blower 100 according to the fourth embodiment further specifies the configuration of the blades 30 in the centrifugal blower 100 according to the first embodiment. Therefore, in the following description, the configuration of the blades 30 of the centrifugal blower 100 according to the fourth embodiment of the present invention will be mainly described with reference to FIGS. 14 to 19.

(Wing 30)
In each cross section CR of the plurality of blades 30 by a plane perpendicular to the rotation axis RS of the main plate 10, the outlet angle β of the blade 30 is centered on the center line CL of the blade 30 and the rotation axis RS passing through the trailing edge portion 36 of the blade 30. Is defined as the angle formed by the tangent line TL2 at the trailing edge portion 36 of the virtual circle C2. As shown in FIG. 15, the exit angle β of the blade 30 increases from the main plate 10 toward the side plate 20 as shown by the exit angle β1 at the position Pe, the exit angle β2 at the position Pf, and the exit angle β3 at the position Pg. .. That is, the exit angle β of the number of blades 30 is the outlet of the cross section CR at the position on the main plate 10 side with respect to the intermediate position Pf between the main plate 10 and the side plate 20 at the trailing edge portions 36 of the plurality of blades 30. The exit angle β of the cross section CR located at the side plate 20 side is larger than the angle β. The intermediate position Pf between the main plate 10 and the side plate 20 in the trailing edge portion 36 is the middle of the length along the trailing edge portion 36 between the main plate 10 and the side plate 20.

[Operational Effects of Centrifugal Blower 100]
In centrifugal fan 100 according to the fourth embodiment of the present invention, outlet angle β of blade 30 increases as it goes from main plate 10 to side plate 20. The centrifugal blower 100 according to Embodiment 4 of the present invention increases the outlet angle β on the side plate 20 side rather than the main plate 10 side and increases the work of the blades 30 on the side plate 20 side to increase the wind speed on the side plate 20 side. The air velocity distribution of the blown air can be made uniform. Further, in the centrifugal blower 100, since the air flow on the side plate 20 side is increased by increasing the blade outer diameter on the side plate 20 side from the main plate 10 side, even if the outlet angle β on the side plate 20 side is increased, the blade surface is reduced. The separation of the air flow is suppressed.

Embodiment 5.
[Configuration of Air Conditioner 200]
FIG. 20 is a sectional view of an air conditioner 200 in which the centrifugal fan 100 according to Embodiment 5 of the present invention is mounted. The air conditioner 200 is a floor-standing type device. However, the air conditioner 200 is not limited to the floor-standing type, and may be another type such as a ceiling-embedded type. The air conditioner 200 passes through the housing 210 that forms the outer shell of the air conditioner 200, the heat exchanger 220 that is arranged inside the housing 210, and the heat exchanger 220 that is arranged inside the housing 210. And a centrifugal blower 100 that forms a flow of air.

(Case 210)
The housing 210 is formed in a rectangular parallelepiped shape. The shape of the housing 210 is not limited to a rectangular parallelepiped shape, and other shapes such as a columnar shape, a prismatic shape, a conical shape, a shape having a plurality of corner portions, and a shape having a plurality of curved surface portions are used. May be A suction port 212 is formed in the upper surface portion 211 of the housing 210, and an air outlet 214 is formed in the lower surface portion 213 of the housing 210. The suction port 212 is an opening for sucking air from the outside to the inside of the casing 210 by the operation of the centrifugal blower 100, and the blowout port 214 allows the air to be sucked from the inside to the outside of the casing 210 by the operation of the centrifugal blower 100. It is an opening for discharging. The formation positions of the suction port 212 and the blowout port 214 are not limited to the configuration. For example, the suction port 212 and the blowout port 214 may be formed on the same surface, or either one of them may be formed on the side surface. The centrifugal blower 100 and the heat exchanger 220 are housed inside the housing 210. The internal space of the housing 210 is divided by a partition plate 215 into a space S11 in which the heat exchanger 220 is stored and a space S12 in which the centrifugal blower 100 is stored. The housing 210 is provided with an electric component 250 for controlling the air conditioner 200.

(Centrifugal blower 100)
The centrifugal blower 100 forms a flow of air that is sucked into the housing 210 through the suction port 212 formed in the housing 210 and blown out from the air outlet 214 formed in the housing 210 into the air-conditioned space. The centrifugal blower 100 includes a bell mouth 230. The bell mouth 230 is arranged between the partition plate 215 and the centrifugal blower 100. The centrifugal blower 100 is connected to the motor 240. The motor 240 is supported by a motor support 241 fixed to the lower surface portion 213 of the housing 210. The motor 240 has an output shaft 242. The boss 12 of the centrifugal blower 100 is attached to the output shaft 242 of the motor 240.
Note that the number of centrifugal blowers 100 arranged in the housing 210 is not limited to one and may be plural.

(Heat exchanger 220)
The heat exchanger 220 is arranged on the upstream side of the centrifugal blower 100 in the flow direction of air in the housing 210 formed by the centrifugal blower 100. The heat exchanger 220 adjusts the temperature of the air that is sucked into the housing 210 from the suction port 212 of the housing 210 and is blown from the air outlet 214 into the air-conditioned space. The heat exchanger 220 may have a known structure. A filter 221 is detachably arranged on the upstream side of the heat exchanger 220 in the flow direction of air in the housing 210 formed by the centrifugal blower 100. The filter 221 removes dust from the air before passing through the heat exchanger 220. Below the heat exchanger 220, a drain pan 222 for collecting condensed water is provided.

[Operation of the air conditioner 200]
When the blades 30 of the centrifugal blower 100 rotate together with the main plate 10, the air in the air-conditioned space is sucked into the housing 210 through the suction port 212 of the housing 210. The air sucked into the housing 210 passes through the filter 221 and then the heat exchanger 220. When passing through the heat exchanger 220, the air passing through the heat exchanger 220 is heat-exchanged with the refrigerant flowing inside the heat exchanger 220, and its temperature and humidity are adjusted. The air that has passed through the heat exchanger 220 is guided by the bell mouth 230 and sucked into the centrifugal blower 100. The air sucked into the centrifugal blower 100 passes between the blades 30 and is blown out toward the outer side in the radial direction of the main plate 10. The air blown out from the centrifugal blower 100 is discharged into the air-conditioned space from the air outlet 214 formed in the lower surface portion 213 of the housing 210.

[Operation and effect of air conditioner 200]
Since the air conditioner 200 includes any one of the centrifugal blowers 100 according to the first to fourth embodiments, it is possible to make the wind speed distribution of the blown air uniform and improve the fan efficiency. can do. Further, since any one of the centrifugal blowers 100 according to the first to fourth embodiments is provided, the turbulent air caused by the wake of the bell mouth and the leakage flow of the air flowing in from the gap between the bell mouth and the side plate 20. It is possible to suppress the noise caused by the collision of the flows.

The configurations described in the above embodiments are examples of the content of the present invention, and can be combined with other known techniques, and the configurations of the configurations are not departing from the scope of the present invention. It is also possible to omit or change parts.

10 main plate, 12 boss, 14 main plate outer peripheral edge portion, 20 side plate, 22 end portion, 24 side plate outer peripheral edge portion, 30 blade, 30a blade outer surface, 30b blade inner surface, 31 inner peripheral edge, 32 outer peripheral edge, 35 front edge portion, 36 trailing edge part, 100 centrifugal blower, 102 suction port, 104 air outlet, 200 air conditioner, 210 housing, 211 upper surface part, 212 suction port, 213 lower surface part, 214 air outlet, 215 partition plate, 220 heat exchanger 221 filter, 222 drain pan, 230 bell mouth, 240 motor, 241 motor support, 242 output shaft, 250 electrical parts.

Claims

A main plate that is driven to rotate,
An annular side plate arranged to face the main plate,
A plurality of wings arranged between the main plate and the side plate,
Equipped with
Each cross section of the plurality of blades by a plane parallel to the main plate is defined as a first cross section,
In the first cross section, the straight line distance between the inner peripheral edge and the outer peripheral edge of each of the plurality of blades around the rotation axis of the main plate is defined as the chord distance,
In the plane perpendicular to the rotation axis passing through the intermediate position of the opening width in the extending direction of the rotation axis of the air outlet formed by the outer circumferential edge section of the main plate and the outer circumferential edge section of the side plate, When the first cross section having is defined as an intermediate cross section,
A centrifugal blower in which the chord distance has a maximum value in the first cross section located closer to the side plate than the intermediate cross section.
The chord distance increases from the main plate toward the side plate, becomes maximum at a position closer to the side plate than the intermediate cross section between the main plate and the side plate, and then decreases toward the side plate. The centrifugal blower according to claim 1.
When each cross section of the plurality of blades by a plane perpendicular to the rotation axis is defined as a second cross section,
The inlet angle of the plurality of blades in the second cross section has a minimum value in the second cross section that is located closer to the side plate than the intermediate position between the main plate and the side plate at the leading edges of the plurality of blades. The centrifugal blower according to claim 1 or 2.
The centrifugal blower according to claim 3, wherein the inlet angle increases from the position of the second cross section having the minimum inlet angle toward the side plate.
Each cross section of the plurality of blades along a plane perpendicular to the rotation axis is defined as a second cross section,
In the second cross section, when the distance perpendicularly connected from the straight line connecting the leading edge portion and the trailing edge portion of each of the plurality of blades to the center line of the blade is defined as the warp height of the blade,
The warp height is
The centrifugal blower according to claim 1 or 2, which has a maximum value in the second cross section at a position closer to the side plate than an intermediate position between the main plate and the side plate at the leading edges of the plurality of blades.
In the second cross section, when the distance perpendicularly connected from the straight line connecting the leading edge portion and the trailing edge portion of each of the plurality of blades to the center line of the blade is defined as the warp height of the blade,
The warp height is
The centrifugal blower according to claim 3 or 4, which has a maximum value in the second cross section at a position closer to the side plate than an intermediate position between the main plate and the side plate at the leading edges of the plurality of blades.
The centrifugal blower according to claim 5 or 6, wherein the warp height decreases from the position of the second cross section having the maximum warp height toward the side plate.
Each cross section of the plurality of blades along a plane perpendicular to the rotation axis is defined as a second cross section,
The outlet angle of the plurality of blades in the second cross section is at the main plate side with respect to the intermediate position between the main plate and the side plate at the trailing edge of the plurality of blades, and the outlet of the second cross section. The centrifugal blower according to claim 1 or 2, wherein the outlet angle of the second cross section located at a position closer to the side plate than a corner is larger.
The outlet angle of the plurality of blades in the second cross section is at the main plate side with respect to the intermediate position between the main plate and the side plate at the trailing edge of the plurality of blades, and the outlet of the second cross section. The centrifugal blower according to any one of claims 3 to 7, wherein the outlet angle of the second cross section located at a position closer to the side plate than a corner is larger.
A centrifugal blower according to any one of claims 1 to 9,
A heat exchanger,
Air conditioner equipped with.