JP5669877B2 - Turbofan and air conditioner - Google Patents

Description

  The present invention relates to a turbo fan and an air conditioner, and more particularly to a turbo fan used in an air conditioner such as air purifier, humidifying / dehumidifying, and air conditioning, and an air conditioner equipped with the turbo fan.

(A) As a blower fan mounted on a conventional ceiling-embedded air conditioner, a turbofan in which the fan blades are formed in a three-dimensional shape is widely used.
For example, the inlet diameter of the blade is gradually increased from the main plate side to the side plate side, the inlet diameter of the side plate side end of the blade is made larger than the suction port diameter of the side plate, and the upper end of the blade is inclined in the rotation direction of the impeller. In addition, the inclination angle formed by the rotation axis of the impeller and the upper end of the impeller on the cross section obtained by flattening the cross section when cut into a cylindrical shape that is concentric with the impeller shaft center from the inner peripheral side of the impeller Each of them is set to increase toward the side and set so that the inclination angle decreases in the vicinity of the side plate (see, for example, Patent Document 1).

  By forming the turbo fan in this way, it is possible to suppress the flow flowing from the upper end portion of the blades from being separated at the blade negative pressure surface, and it is possible to suppress the deterioration of the blowing performance and the increase of the turbulent noise.

  (Ii) As another conventional example, the position of the side plate side coupling point at the trailing edge of each blade is offset by a predetermined amount in the counter-rotating direction from the main plate side coupling point, and at the blade leading edge of each blade. A device is disclosed in which the position of the side plate side coupling point is offset by a predetermined amount in the rotational direction of the impeller from the position of the main plate side coupling point (see, for example, Patent Document 2).

  By forming the turbo fan in this way, the blade pressure surface inclines toward the side plate at the blade trailing edge, so that the force acting on the air by the pressure surface is in the direction closer to the side plate, so the separation at the outlet side on the side plate side Flow can be prevented. Furthermore, since the chord length on the side plate side of the blade having a large flow velocity at the blade leading edge becomes longer, the flow flowing into the blade leading edge near the main plate moves toward the side plate, and the separation flow on the side plate side outlet side of the blade. Therefore, the wind speed distribution on the front side of the heat exchanger arranged on the downstream side of the impeller is made uniform in the entire vertical direction.

  (C) Further, as another conventional example, the blades extend from the front edge to the rear edge, the position of the joint end with the side plate is shifted to the rotational direction side with respect to the joint end with the main plate, and the front of the blade The edge of the side plate on the edge side is inclined to the rotation direction side, and the blade front edge is inclined inward in the radial direction in the rotation direction, and the inclination angle (inlet angle α) is the main plate. The center side is larger than the side plate and the side plate side, the side plate side is smaller than the main plate side, and further, the blade trailing edge is inclined in the counter-rotating direction radially outward, and the inclination angle (exit angle β) Are disclosed in which the central side is larger than the main plate side and the side plate side, respectively (for example, see Patent Document 3).

  By forming the turbo fan in this way, the side plate side end portion on the front edge side of the blade, where the velocity component in the axial direction of the inflowing air is particularly large, is inclined in the rotation direction and is aligned with the inflow direction of the inflowing air. Therefore, it is possible to reliably prevent peeling that tends to occur on the side opposite to the rotation direction of the blades, and to improve performance and reduce noise. Further, since the leading edge side inclination angle α is large at the center portion, air can be taken in from the inner peripheral side very smoothly. Further, when the inclination angle α is smaller on the side plate side than on the main plate side, air can be smoothly taken in due to the shape along the inflow angle. Further, in the blade trailing edge, the inclination angle (exit angle β) is larger on the center side than the main plate side and the side plate side, so that the air blown to the outer peripheral side can be made uniform.

Japanese Patent Laid-Open No. 10-30590 (page 4, FIG. 8) Japanese Patent No. 2701604 (page 4, FIG. 3) Japanese Patent No. 3861008 (page 7, FIG. 4)

However, the turbofan and air conditioner disclosed in Patent Documents 1 to 3 have the following problems.
(A) The turbofan disclosed in Patent Document 1 has poor assemblability. That is, when the upper end of the blade is tilted in the direction of rotation of the impeller, at least the side plate and the blade are molded separately, and then the turbo fan in which the impeller is integrally formed by welding, fitting, etc., rotates the side plate on the blade. Since the side plate side at the upper end of the blade has an inclined shape because a force is applied in the axial direction and pressed, the stress is applied to the main plate side coupling point of the blade, and the force is not easily applied to the side plate side of the blade.

  (B) When molding with a thermoplastic resin, the material increases, the weight also increases, and the processability is poor. That is, there is a possibility that sink marks may occur when molding with a thermoplastic resin, and the thickness of the blade with poor workability is substantially the same from the main plate to the side plate in the impeller height direction. In the case of an airfoil wing that gradually increases in thickness from the inner periphery of the impeller and becomes thinner toward the outer periphery of the impeller, for example, near the center of the blade where the thickness increases, the blade is inclined in a side view. The wall thickness is increased at the upper end of the blade, the material is increased, and the weight is increased. Further, when molding with a thermoplastic resin, there is a risk of sink marks, and the processability is poor.

  (C) Furthermore, since the amount of inflow at the side plate side coupling portion of the blade increases because the inclination angle of the upper end of the blade increases at least from the inner periphery of the impeller toward the outer periphery, the flow that flows in from the impeller inner periphery side of the blade May cause noise and vibration to deteriorate the surrounding environment (hereinafter referred to as “risk of noise deterioration”).

(D) Further, in the turbofan disclosed in Patent Document 2, the side plate side coupling point of the blade trailing edge is disposed downstream of the impeller by offsetting the predetermined amount in the counter-rotating direction from the main plate side coupling point. Although the uniformity of the wind speed distribution on the front side of the heat exchanger is improved, the flow concentrates on the side plate side of the trailing edge of the blade at the exit of the impeller, which may cause noise deterioration.
(E) Also, the side plate side coupling point of the blade leading edge is offset by a predetermined amount in the rotational direction from the main plate side coupling point, so that peeling near the side plate side coupling point is suppressed, but the middle of the blade leading edge There is still room for noise reduction because there is still delamination from the site to the side plate side coupling point.

(F) Further, the side plate side coupling point is inclined in the rotation direction with respect to the main plate side coupling point, and the main plate surface and the pressure surface of the blade (counter rotation direction surface) form an acute angle smaller than 90 °. Therefore, the inflow flow from the front edge drifts to the main plate side, and a separation region remains on the side plate side of the blade trailing edge.
(G) Further, the blade main plate side coupling point is inclined with respect to the side plate from the side plate side coupling point that is welded to the side plate by offsetting the side plate side coupling point in the reverse direction on the front edge side and the rear edge side. As with the turbo fan disclosed in, the assemblability is poor.

(H) On the other hand, in the turbofan disclosed in Patent Document 3, the side plate side coupling point is shifted in the rotational direction with respect to the main plate side coupling point from the front edge to the rear edge of the blade, and the side plate side end portion on the front edge side Is inclined to the rotational direction side, the separation of the suction flow at the side plate side end of the blade and the side plate side coupling point is suppressed, but the inflow flow from the front edge drifts to the main plate side and the blade trailing edge A peeling area remains on the side plate side of the plate.
(I) In addition, since the entire blade is inclined in the rotation direction, at least the side plate and the blade are formed separately, and then the impeller is integrally formed by welding, fitting, etc. Since a force is applied in the direction of the rotational axis from the side of the blade and the coupling is performed, stress is applied to the coupling point on the main plate side of the blade, and the force is not easily applied to the side plate side of the blade, resulting in instability.

  The present invention has been made to solve the above-described problems. By suppressing the separation area at the front edge and side plate side edge of the blade, and the rear edge, the low noise, assembling performance and An object is to obtain a turbo fan and an air conditioner equipped with the turbo fan, which have good workability and can suppress the deterioration of performance to a minimum even when ventilation resistance is added.

A turbofan according to the present invention is an annular side plate having a disk-shaped main plate having a boss that is a fixed portion to which a rotating shaft of a motor is fixed, and a side plate opening at the center that forms a wind guide wall together with the main plate. And a plurality of blades installed across the main plate and the side plate, wherein the blades are rotated as the blades move from the blade leading edge to the blade trailing edge in plan view. The blade outer peripheral surface and the blade inner peripheral surface are located away from the shaft and in the counter-rotating direction, and the central range in the height direction is substantially parallel to the rotating shaft at the blade leading edge, And it has the base part inclined so that it might be located in the radial direction outer side of the said main board, so that the range close | similar to the said main board of the said blade front edge part was approached.

(I) Since the turbo fan according to the present invention has the above-described configuration, when the wind speed distribution at the fan outlet is uniform and the heat exchanger is provided on the downstream side of the turbo fan, the height direction is at least in the vicinity of the fan outlet. Therefore, the flow through the surface without passing through the heat exchanger due to the difference in wind speed is suppressed, the pressure loss is reduced, and the noise can be reduced.
(Ii) In addition, the air conditioner according to the present invention has a pressure loss body such as a filter that can ventilate the turbofan suction port, so that separation at the blade leading edge portion of the turbofan is suppressed and operation with low noise is performed. Is possible.

The longitudinal cross-sectional view explaining the air conditioner which concerns on Embodiment 1 of this invention. The perspective view explaining the turbo fan which concerns on Embodiment 2 of this invention. The plane partial sectional view which looked at the turbo fan shown in FIG. 2 from the fan inlet side. The side view which shows the XX cross section in FIG. The side view which shows the blade | wing of the turbo fan shown in FIG. Sectional drawing which shows the L1-L1 cross section in FIG. Sectional drawing which shows the L2-L2 cross section in FIG. Sectional drawing which shows the L3-L3 cross section in FIG. Sectional drawing which shows the L4-L4 cross section in FIG. The top view which shows the L5-L5 cross section in FIG. The longitudinal cross-sectional view which shows the K1-K1 cross section in FIG. The longitudinal cross-sectional view which shows the K2-K2 cross section in FIG. The relationship figure of the noise value at the time of the same air volume with trailing edge inclination-angle (alpha). FIG. 5 is a relationship diagram between a circumferential bending angle γ and a noise value at the same air volume. FIG. 6 is a relationship diagram between the outlet angle difference Δβ2 and the noise value at the same air volume. FIG. 5 is a relationship diagram between a bending angle ε and a noise value at the same air volume. The relationship diagram of the noise value at the same air volume as the inlet angle difference Δβ1. The perspective view explaining the turbo fan which concerns on Embodiment 3 of this invention. The longitudinal cross-sectional view of the blade | wing of the turbo fan shown in FIG.

[Embodiment 1: Air conditioner]
1 is a longitudinal sectional view for explaining an air conditioner according to Embodiment 1 of the present invention. The air conditioner in Embodiment 1 which concerns on this invention mounts the turbo fan which concerns on Embodiment 2 mentioned later, and is demonstrated using figures below.
In FIG. 1, a ceiling-embedded air conditioner (hereinafter referred to as “air conditioner”) 10 is installed in a state of being embedded in a rectangular hole formed in a ceiling 21 of a room 20. That is, the air conditioner 10 is a box having an opening on the lower side, and has an upper top plate 10a and a side plate 10b disposed on the lower side facing the top plate 10a. At this time, the side plate 10b has a side plate opening (communicating with the main body suction port 10c) in the center, and the lower end is located on the substantially same plane as the ceiling 21, so the opening of the air conditioner 10 is also Further, it is located on substantially the same plane as the ceiling 21.

  Furthermore, a substantially rectangular decorative panel 11 in plan view is attached to the side plate 10b or the ceiling 21 so as to cover the lower end of the side plate 10b and the rectangular hole of the ceiling 21 in plan view. Near the center of the decorative panel 11, a suction grill 11a that is an air inlet to the air conditioner 10, a filter 12 that removes air after passing through the suction grill 11a, and each side of the decorative panel 11 are formed. The panel outlet 11b is further provided with a wind vane 13 at each panel outlet 11b.

Further, inside the air conditioner 10, the turbo fan 1, a bell mouth 14 that forms a suction air passage of the turbo fan, a fan motor 15 that rotationally drives the turbo fan 1, and sucked room air (hereinafter “suction”). Heat exchangers 16 that exchange heat with each other are arranged. At this time, the heat exchanger 16 is formed in a substantially C shape in a plan view, is erected so as to surround the outer peripheral side of the turbofan 1, and is connected to an outdoor unit (not shown) by a connection pipe. .
Moreover, the main body inlet 10c is formed in the center part of the air conditioner 10, and the main body outlet 10d is formed around the main body inlet 10c. At this time, the main body suction port 10 c communicates with the suction grille 11 a of the decorative panel 11, and the main body outlet 10 d communicates with the panel outlet 11 b of the decorative panel 11.

  When the turbo fan 1 rotates by the air conditioner 10 configured in this way, the air in the room 20 passes through the suction grille 11a of the decorative panel 11, passes through the filter 12, and is removed, and further, the main body inlet 10c and the bell After passing through the mouse 14, it is sucked into the turbofan 1. Then, it blows out toward the heat exchanger 16. Then, air that has been subjected to heat exchange or dehumidification such as heating or cooling in the heat exchanger 16 is blown out from the panel blower outlet 11b toward the room 20 through the main body blower outlet 10d while being controlled by the wind direction vane 13. The Therefore, air conditioning of the room 20 (hereinafter sometimes referred to as “air conditioning”) is performed.

[Embodiment 2: Turbofan]
2 to 17 illustrate a turbo fan according to Embodiment 2 of the present invention. FIG. 2 is a perspective view, FIG. 3 is a partial plan view of a plane viewed from the fan inlet side, and FIG. 5 is a side view showing a part, FIG. 6 to FIG. 9 are plan views showing the part, FIG. 10 is a plan view showing the part, and FIGS. 11 and 12 are parts. FIG. 13 to FIG. 17 are relationship diagrams showing the relationship between the noise value and the angle of each part.
2 corresponds to a perspective view when the ceiling 21 is looked up in FIG. Further, in FIG. 4 and FIG. 1 (Embodiment 1), since the top and bottom are reversed, the sucked air is sucked from the upper side of FIG. 4 and blown out in the left-right direction of FIG. For convenience, the vertical direction in FIG. 4 is referred to as a “height direction”, and the horizontal direction and the front / back direction of the paper surface are referred to as a “horizontal direction”. Further, in FIG. 1 (Embodiment 1) and each drawing, the same portions are denoted by the same reference numerals, and a part of the description is omitted.

  13 is a relationship diagram of the trailing edge inclination angle α and the noise value at the same air volume, FIG. 14 is a relationship diagram of the circumferential curve angle γ and the noise value at the same air volume, and FIG. 15 is the exit angle difference Δβ2. It is a relationship diagram with the noise value at the time of the same air volume. FIG. 16 is a graph showing the relationship between the bending angle ε at the blade leading edge tip 4a3 and the noise value with respect to the ventilation resistance ratio when dust is accumulated on the filter disposed on the suction side when the air volume is the same. is there. FIG. 17 shows the inlet angle at the leading edge of the blade leading edge relative to the inlet angle at the inner circumferential edge of the leading edge at the height position at the concave bottom where the vertical sled line C12 is the most reverse rotation direction on the blade outer circumferential surface. Is a relationship diagram between the angle difference Δβ1 and the noise value at the same air volume.

2 to 5, a turbofan 1 includes a main plate 2 that is a rotating body (disk) having a substantially chevron-shaped cross section, and a side plate 3 that is a ring having a substantially arc-shaped cross section that is disposed to face the peripheral edge of the main plate 2. And a plurality of blades 4 disposed across the main plate 2 and the side plate 3 are integrally formed.
In other words, the main plate 2 is formed with a boss 2a, which is a fixed portion to the rotation axis O of the fan motor 15, at the center (a convex portion having a substantially mountain-shaped cross section). Therefore, the rotation axis O is parallel to the height direction and perpendicular to the horizontal direction.

  The side plate 3 that is a ring has a central side plate opening that forms a fan suction port 1a. Moreover, the peripheral part (substantially mountain-shaped base part of the cross section) of the main plate 2 and the side plate 3 serve as a wind guide wall, and a space surrounded by these forms a fan outlet 1b. That is, in FIG. 1, since the cross section of the peripheral part of the main plate 2 and the cross section of the side plate 3 are both higher toward the outer periphery, they have risen (since FIGS. After that, a wind flow toward the outer periphery is formed in the horizontal direction.

(Arrangement of feathers)
In the plan view, the blade 4 moves away from the rotation axis 0 as the blade leading edge portion 4a becomes the blade trailing edge portion 4e, and the edge near the side plate 3 of the blade 4 is close to the blade trailing edge portion 4e. In the range (4ec4-4g1), it is joined to the side plate, and in the range (4g1-4a3) close to the blade leading edge 4a, it is separated from the side plate 3 and located in the side plate opening. As the blade 4 moves away from the main plate 2 and approaches the side plate 3, the thickness t (same as the distance between the blade outer peripheral surface and the blade inner peripheral surface) in the horizontal cross section orthogonal to the rotation axis O of the blade 4 gradually increases. The hollow structure has a hollow inside and an opening outside the impeller of the main plate 2.

(Blade trailing edge)
In FIG. 5, the blade trailing edge 4 e of the blade 4 is located on a virtual cylinder connecting the outer peripheral edge of the main plate 2 and the outer peripheral edge of the side plate 3, and has at least two or more inflection points on the virtual cylinder. It is wavy. That is, the intersection of the horizontal warp line C1 and the blade trailing edge 4e is in the height direction, and the rotation point is at a predetermined position on the main plate 2 side from the center of the fan outlet 1b with respect to the intersection 4ec1 which is the main plate side coupling point. Intersection 4ec2 which is a main plate side bending point which is curved in the rotational direction in a convex manner, intersection 4ec3 which is a side plate side bending point which is curved in a concave shape on the side plate 3 side from the center of the fan outlet 1b, and the side plate 3 The intersection 4ec4 which is a side plate side coupling point is shown.
In other words, the straight line G connecting the main plate side coupling point 4ec1 and the side plate side coupling point 4ec4 has an upright shape in the vicinity of the main plate 2 and the side plate 3 parallel to the rotation axis O, and the main plate side bending point 4ec2 and the side plate side bending point 4ec3. The main plate 2 side is inclined in the rotation direction A with respect to the side plate 3 side, and the blade trailing edge 4e is formed in a substantially S shape.

At this time, the blade trailing edge 4e is located on a virtual cylindrical surface connecting the outer peripheral edge of the main plate 2 and the outer peripheral edge of the side plate 3, and a straight line G connecting the main plate side coupling point 4ec1 and the side plate side coupling point 4ec4 is a rotation axis. Parallel to O and perpendicular to the surface of the outer edge of the main plate 2 (same as normal to the normal).
Further, the blade trailing edge 4 e is shaped so as to be parallel to the normal line of the side plate 3 in the vicinity of the side plate 3. Furthermore, the main plate side bending point 4ec2 which is the maximum protruding position of the main plate side bending portion in the rotation direction A side and the side plate side bending point 4ec3 which is the maximum protruding position of the side plate side bending portion in the direction opposite to the rotation direction A. In between, since it protrudes in the rotation direction A as it approaches the main plate 2, it is inclined in a side view and has a substantially S shape.

  Accordingly, the intake air is divided into the height direction main plate 2 side and the central portion side of the fan outlet 1b by the main plate side curved point 4ec2 on the outer peripheral surface 4b of the blade, thereby preventing the concentration of the flow to the main plate 2 side. doing. Further, a force is applied in the direction of the side plate 3 by the inclined portion 4e5 between the main plate side bending point 4ec2 and the side plate side bending point 4ec3 to induce the flow. Further, the side plate side bending point 4ec3 to the side plate side coupling point 4ec4 are the side plate 3 of the fan outlet 1b that flows from the periphery of the side plate side coupling point 4g of the front edge side plate side end portion 4a1 of the blade 4 on the blade inner peripheral surface 4c. The wind is guided to the side.

(Cross section of blade)
Next, a horizontal cross-sectional shape in the height direction of the blade 4 will be described.
6 to 10 show the L1-L1 cross section, the L2-L2 cross section, the L3-L3 cross section, the L4-L4 cross section, and the L5-L5 plane shown in FIG. 4, respectively. Further, the rotation direction is indicated by “arrow A”.
6 shows the L1-L1 cross section at the main plate side end 4d of the blade, which is the joint with the main plate 2, FIG. 7 shows the L2-L2 cross section on the main plate 2 side from the center of the fan outlet 1b, and FIG. FIG. 9 shows an L4-L4 cross section passing through the surface of the side plate 3 of the fan air outlet 1b from the center of the fan air outlet 1b, FIG. 10 shows a side plate 3 for one blade 4 of the blade 4. The L5-L5 plane when the is removed is shown.

And about the L1-L1 cross section (FIG. 6), the thickness center line in the cross section (same as the center of a blade | wing inner peripheral surface and a blade | wing outer peripheral surface) is shown by "horizontal sled line C1," “Intersections between the blade leading edge 4a” and “intersections between the horizontal sled line C1 and the blade trailing edge 4e” are indicated by “4ac1” and “4ec1”.
For the L2-L2 cross section (FIG. 7), the thickness center line in the cross section is indicated by “horizontal sled line C2”, “intersection of horizontal sled line C2 and blade leading edge 4a” and “horizontal sled line C2”. And “4c2” and “4ec2”.
Similarly, for the L3-L3 cross section (FIG. 8), “horizontal warp line C3” is indicated by “4ac3” and “4ec3”. Further, regarding the L4-L4 cross section (FIG. 9), “horizontal warp line C3” is indicated by “4ac4” and “4ec4”. In addition, in order to clarify the phase in the height direction, “4ac1” and “4ec1” are appended to each drawing.

Further, in FIGS. 6 to 9, the shape of the blade 4 in each cross section gradually increases in thickness from the front edge inner peripheral side end portion 4a2 toward the blade center portion, and toward the blade rear edge portion 4e. A wing that gradually decreases.
In the L1-L1 cross section shown in FIG. 6, it inclines backward with respect to the rotation direction A and curves outward in the radial direction, and in the L2-L2 cross section shown in FIG. In the L3-L3 cross section shown in FIG. 8, the blade trailing edge 4e is warped in the direction opposite to the rotation direction A from the main plate side coupling point 4ec1.

In the L4-L4 cross section shown in FIG. 9, the side plate side connection point 4ec4 and the main plate side connection point 4ec1 in the L1-L1 cross section shown in FIG. The circumferential end 4a2 side is curved outward in the radial direction and exhibits a reversely warped shape.
Further, in the plan view shown in FIG. 10, the main plate side bending point 4ec2 and the side plate side bending point 4ec3 are disposed in a state of having a predetermined circumferential bending angle γ across the main plate side coupling point 4ec1 and the side plate side coupling point 4ec4. Is formed.

In FIG. 6 (L1-L1 cross section), a tangent line E1 of the horizontal sled line C1 and a tangent line of a circle concentric with the rotation axis O and passing through the intersecting point 4ec1 at an intersection point 4ec1 between the horizontal sled line C1 and the blade trailing edge 4e. The angle (acute angle) formed with F1 is referred to as “exit angle β21”.
In FIG. 7 (L2-L2 cross section), a tangent line E2 of the horizontal sled line C2 at a crossing point 4ec2 between the horizontal sled line C2 and the blade trailing edge 4e, and a tangent line F2 concentric with the rotation axis O and passing through the crossing point 4ec2 The angle (acute angle) formed by is referred to as “exit angle β22”. Similarly, “exit angle β23” is defined in FIG. 8 (L3-L3 cross section), and “exit angle β24” is defined in FIG. 9 (L4-L4 cross section).
At this time, the blades 4 are formed so that the exit angles thereof have a relationship of “β23 <β21 = β24 <β22”.

(Blade leading edge)
2 and 3, the shape of the blade leading edge 4a on the air inlet side of the blade 4 is composed of the side plate side end 4a1 front edge inner peripheral side end 4a2, and the blade leading edge tip 4a3 is bent. It is continuous as a point. Then, in the height direction, the side plate side end portion 4a1 becomes closer to the “side plate side coupling portion 4g (see FIG. 4) that is a close contact portion between the blade 4 and the side plate 3” from the blade leading edge tip portion 4a3. It is inclined toward 1a. That is, the side plate side end portion 4 a 1 approaches the side plate 3 while being inclined so as to approach the normal direction of the side plate 3.

In FIG. 3, the intersection of the horizontal sled line C1 and the front edge inner peripheral side end 4a2 is defined as “intersection 4ac1”, the intersection of the horizontal sled line C1 and the blade trailing edge 4e is defined as “intersection 4ec1”, and the intersection 4ac1 A straight line connecting the intersection 4ec1 is a “string line D”.
A vertical cross section perpendicular to the chord line D in the vicinity of the front edge inner peripheral end 4a2 is referred to as “K1-K1 cross section”, and the blade 4 in the K1-K1 cross section is illustrated in FIG. Further, a vertical section perpendicular to the chord line D at the rotation direction front end portion 4g1 of the side plate side coupling portion (same as the boundary between the joining range and the range located at the side plate opening) is referred to as “K2-K2 cross section”, and K2-K2 The blade 4 in cross section is shown in FIG.
11 and 12, the thickness center line in the height direction of the blade 4 in the K1-K1 cross section and the K2-K2 cross section (same as the center of the blade outer peripheral surface and the blade inner peripheral surface) is expressed as “vertical sled line”. C12 ”, and the angle between the vertical sled line C12 and the rotation axis O in the blade leading edge tip portion 4a3 (K1-K1 cross section) and the side plate joint portion 4g1 (K2-K2 cross section) are respectively“ curved angle ε1 ”and“ The bending angle ε2 ”.

2, 11, and 12, the blade 4 approaches the blade leading edge 4 a in plan view in a range away from the side plate 3 at the end edge close to the side plate 3 of the blade 4 (same as the range located in the side plate opening). It is curved so as to be located outward in the radial direction, and in a side view, the curved range is enlarged so as to be farther from the edge as it approaches the blade leading edge 4a.
That is, on the side plate 3 side of the blade leading edge side plate side end 4a1 and the leading edge inner peripheral side end 4a2, the rotational direction tip 4g1 on the blade outer peripheral surface of the side plate side coupling portion 4g is used as a fulcrum, and the blade leading edge tip 4a3 is used. As a power point, as the bending angle ε moves toward the inner peripheral side of the impeller (same as approaching the blade leading edge 4a), it is curved radially outward so as to increase.

Therefore, since the curved range is formed in a substantially triangular shape in a side view, the outer peripheral surface 4b of the blade 4 is gradually moved toward the main plate 2 from the front end portion 4g1 in the rotational direction toward the front end inner peripheral end portion 4a2. A diagonal “folding line B” is generated.
Further, as shown in FIGS. 4 and 11, the blade wall thickness T is gradually increased so that the outer peripheral surface 4b of the blade on the main plate 2 side of the blade leading edge 4a is curved radially outward, and the vertical sled line is formed. C12 is also curved outward in the radial direction.

In the K2-K2 cross section shown in FIG. 12, the outer peripheral surface 4b of the blade is substantially perpendicular to the surface of the outer edge portion of the main plate 2, and only the side plate 3 side of the inner peripheral surface 4c of the blade is radially outward. The blades 4 are curved, and as a whole, the blades 4 are substantially upright from the main plate 2 toward the side plates 3 (as they become higher) while being reduced in thickness.
The acute entrance angles β11, β12, β13, and β14 shown in the cross sections of FIGS. 6 to 10 are “β14 <β11”, and β12 and β13 at the center in the height direction are at least β11 and β14. In order to become larger (β12> β11, β13> β14), the inlet angle β1 gradually increases from the blade leading edge tip 4a3 to the side plate 3 radially inward, and the inlet angle β14 of the blade leading edge tip 4a3. Is formed to be the smallest.
As described above, at least the blade leading edge 4a has a concave shape with respect to the rotational direction A in the side plate 4a1 side and the main plate 2 side of the blade outer peripheral surface 4b in a side view from the inner peripheral side, and the blade inner peripheral surface 4c. Is formed in a shape curved radially outward.

(Action / Effect)
Since the turbo fan 1 is configured as described above, as shown in FIG. 2, when it is rotated in the rotation direction A by the fan motor 15, the indoor air sucked from the fan suction port 1a (same as the sucked air) After passing through the blades 4, the air is blown out substantially radially from the fan outlet 1b. At this time, the following operations and effects are achieved.

(I) The wind speed distribution at the fan outlet 1b is made uniform. As a result, when the heat exchanger 16 is provided on the downstream side of the turbofan 1, it flows uniformly over the height direction at least in the vicinity of the fan outlet 1b, so that it flows on the surface without passing through the heat exchanger 16 due to the wind speed difference. The next flow is suppressed, pressure loss can be reduced, and noise can be reduced (see FIG. 1).
Further, since the vicinity of the main plate 2 and the side plate 3 of the blade trailing edge portion 4e is upright, the blade trailing edge portion 4e is welded compared to the main plate 2 and the side plate 3 that are inclined with respect to the main plate 2 and the side plate 3 as in the conventional turbofan. A force parallel to the rotation axis O is accurately applied at the time of assembly, and a welding failure due to the escape of the blade 4 is suppressed.

  (Ii) Further, a “rear edge inclination angle α2”, which is an inclination angle formed by the inclined portion 4e5 between the main plate side bending point 4ec2 and the side plate side bending point 4ec3, and the parallel line G to the rotation axis O, is set to “10 ° to 30 ° ". Therefore, in the fan blower outlet 1b, a flow does not concentrate too much to the side plate 3 side of the outer peripheral surface 4b of the blade. Further, on the side plate 3 side of the blade inner peripheral surface 4c, the flow flowing in from the blade front edge side plate side 4a1 of the blade does not concentrate too much. Therefore, the noise becomes low as in the relationship between the trailing edge inclination angle α and the noise value at the same air volume (see FIG. 13).

  (Iii) Further, in the plan view of FIG. 10, the circumferential curve angle γ formed by the straight line connecting the impeller rotation center (same as the rotation axis) O, the main plate side curve point 4ec2, and the side plate side curve point 4ec3 is set to “5 ° to 15”. ° ”. Therefore, when the heat exchanger 16 is disposed on the downstream side of the fan outlet 1b, the turbo fan 1 rotates, the blade trailing edge 4e approaches the heat exchanger 16, and the ventilation resistance increases locally. However, the wind flow is dispersed. Similarly to the effect of the trailing edge inclination angle α, the flow does not concentrate too much on the side plate 3 side of the outer peripheral surface 4b of the blade at the fan outlet 1b, and the front side of the blade 4 on the side plate 3 side of the inner peripheral surface 4c of the blade. Since the flow flowing in from the edge side plate side 4a1 does not concentrate too much, the noise becomes low as in the relationship between the circumferential curve angle γ and the noise value at the same air volume (see FIG. 14).

(Iv) And in each sectional view of the blade in the plane orthogonal to the rotation axis, the exit angle β22 at the main plate side bending point 4ec2 and the exit angle β23 at the side plate side bending point 4ec3 with respect to the rotation direction A of the blade trailing edge. The “angle difference Δβ2”, which is a difference from the above, is between “20 to 35 °”. Therefore, in the air conditioner 10, the distance between the heat exchanger 16 (on the fan blowing side, which is a substantially C-shaped in a plan view, which is a pressure loss body capable of passing air) and the fan outlet 1b varies in the circumferential direction. However, since the blade trailing edge portion 4e is formed in a substantially S-shape that curves unevenly, the air flow is regulated by the substantially S-shape.
For this reason, conventionally, in the region where the fan 1 and the heat exchanger 16 are close to each other, the flow is concentrated on the main plate 2 side of the fan outlet 1b, and the separation is large on the side plate 3 side and the noise deterioration is large. The change is small and the generation of noise is suppressed (refer to FIG. 15 showing “relationship between outlet angle difference Δβ2 and noise value at the same air flow”).

(V) When air flows in at the blade leading edge portion 4a, the side plate 3 side and the main plate 2 side of the outer peripheral surface 4b are concave with respect to the rotation direction A in a side view from the center side (rotary axis O). Since it is curved, the side plate 3 side of the front edge inner peripheral side end portion 4a2 of the blade 4 and the side plate side attracting portion 4b1 (front edge side plate side end portion 4a1 of the outer peripheral surface 4b of the blade are curved radially outward. In this case, the turbulence is suppressed without the intake air colliding with the outer peripheral surface 4b, and the air is introduced smoothly.
Therefore, it is possible to increase the air flow rate when the fan rotation speed is the same, and to reduce the fan rotation speed with respect to the air flow required for heat exchange of the air conditioner 10, thereby reducing noise. In addition, the rotational drive of the fan can be reduced in torque, and the power consumption of the motor can be reduced.

(Vi) Since the main plate 2 side of the outer peripheral surface 4b of the blade at the blade leading edge 4a is curved radially outward, the flow passing through the surface of the main plate 2 from the boss 2a Concentration of the flow toward the main plate 2 side is suppressed together with the flow flowing in from the front edge inner peripheral side end 4a2.
Further, the flow is smoothly introduced into the outer peripheral surface 4b of the blade without colliding with the blade 4, and the disturbance is suppressed.
As a result, compared to the conventional wind speed distribution concentrated on the main plate side of the fan outlet, the blown wind speed distribution can be made uniform and the noise can be reduced by suppressing separation on the side plate side and avoiding concentration on the main plate side. .

  (Vii) Since the side plate 3 side of the blade inner peripheral surface 4c of the blade leading edge 4a is formed to be inclined radially outward and curved, the intake air of the blade inner peripheral surface 4c is Then, it smoothly flows toward the blade trailing edge 4e along the inclined curved surface. Therefore, since the peeling that has occurred in the vicinity of the side plate 3 in the conventional turbofan is suppressed, the noise can be reduced.

(Viii) The chord line D in the horizontal section of the main plate side end 4d of the blade, with the tip 4g1 in the rotational direction on the outer peripheral surface 4b of the blade of the side plate side coupling portion 4g as a fulcrum and the blade leading edge tip 4a3 as a power point. In the longitudinal cross-sectional view orthogonal to the "circular angle ε (the same as the angle formed by the vertical warp line C12 and a straight line parallel to the rotation axis O)" is increased radially outwardly toward the impeller inner peripheral side. Is curving towards. That is, the side plate 3 side and the front edge side plate side end portion 4a1 of the front edge inner peripheral side end portion 4a2 of the blade 4 are directed toward the blade outer peripheral surface (same as the rotation direction surface) 4b of the blade 4 (side plate side coupling portion). ) In the radial direction so that a fold line B (oblique, see FIG. 2) gradually toward the main plate 2 side is generated. ing.
Therefore, compared to a conventional curved line starting from a horizontal line perpendicular to the rotation axis O, the inflow amount on the side plate 3 side of the front edge inner peripheral side end portion 4a2 of the blade 4 and the inflow amount on the front edge side plate side end portion 4a1. And the difference is reduced.

  (Ix) Further, the leading edge of the blade leading edge 4a3 and the leading edge inner peripheral side edge 4a2 and the leading edge side plate side edge 4a1 are connected in a substantially triangular shape, so that the leading edge of the blade leading edge The vertical vortex generated at the front edge inner peripheral side end 4a2 and the front edge side plate side end 4a1 is made uniform with 4a3 as the center, and the air is attracted onto the blade inner peripheral surface 4c and stabilized. Accordingly, dust is deposited on the filter 12 (which is a pressure-dissipating body that can be ventilated disposed on the fan suction port 1a side) as when mounted on the air conditioner 10 (see FIG. 1), and the ventilation resistance is reduced. Even if it is increased, separation of the air flow hardly occurs, and noise deterioration can be suppressed to a small level.

  (X) FIG. 16 is a relationship diagram between the “noise value with respect to the draft resistance ratio” and the bending angle ε, and the bending angle ε of the blade leading edge tip 4a3 is the same as that at the bending angle ε. is there. That is, it is a relationship diagram of “noise value with respect to ventilation resistance ratio” that is a ratio of a value when dust is accumulated on a filter disposed on the suction side to a value when dust is not accumulated. And as shown in FIG. 16, if it is the range of "(epsilon) 1 = 25 degrees-45 degrees", even if the ventilation resistance in the fan inlet 1a changes, it will be hard to peel off, and the low noise turbo fan and air conditioner Is obtained.

  (Xi) Further, as shown in FIG. 12, the blade 4 has a hollow structure in which the wall thickness T decreases from the main plate 2 toward the side plate 3 in the fan height direction and the main plate 2 has an opening 2b outside the impeller. The weight of the fan is reduced. Therefore, when the fan motor is started, the starting torque applied to the boss 2a can be reduced and the twist is suppressed, so that the durability of the turbo fan 1 is improved.

  (Xii) Then, the blade 4 has a longitudinal section K1-K1 shown in FIG. 6 (rotational tip 4g1 of the side plate side coupling portion of the blade 4 perpendicular to the chord line D in the horizontal section of the main plate side end 4d of the blade blade). And a predetermined range toward the blade trailing edge 4e on the downstream side thereof are formed so as to be substantially upright with respect to the main plate 2 in parallel with the rotation axis O. Therefore, when the side plate 3 is pressed against the blade 4 in the direction parallel to the rotation axis O in order to weld the blade 4 and the side plate 3 together, the conventional blade is inclined with respect to the main plate 2. “Stress concentration at the main plate side end portion 4d” is suppressed, buckling of the blades 4 is prevented, assembly is easy, and production reliability can be improved.

(Xiii) With respect to the entrance angle β1 in each cross-sectional view of the blade 4 in the plane orthogonal to the rotation axis O, the entrance angle β14 at the blade leading edge tip 4a3 is the smallest in the blade leading edge 4a. The inlet angle β1 near the center of the impeller height direction at the front edge inner peripheral end 4a2 is larger than at least the inlet angle β11 at the main plate side and the inlet angle β14 at the front end of the blade front edge. It is formed radially inward. That is, the relation of “β1>β11> β14” is established.
In addition, the leading edge side plate end 4a1 of the blade 4 is formed so that the inlet angle β1 gradually increases from the blade leading edge tip 4a3 to the side plate coupling portion 4g. It is possible to reduce the “incident angle δ”, which is an angle difference between the “suction flow J” on the horizontal section orthogonal to the rotation axis O in the portion 4a2 and the entrance angle β1, and attract the suction air smoothly with little separation. And noise reduction can be achieved.

  (Xiv) Also, from the blade leading edge tip 4a3 to the side plate side coupling portion 4g of the leading edge side plate side end 4a1, the suction flow is induced in the radial direction at the inclined portion toward the fan suction port 1a, By gradually increasing the inlet angle β, it is further attracted in the radial direction, the separation on the side plate 3 side can be suppressed, and the wind speed distribution at the fan outlet 1b can be made uniform.

(Xv) In addition, the vertical sled line C12 on the outer peripheral surface 4b of the blade has an entrance angle at the front edge inner peripheral side end 4a2 (see FIGS. 7 and 11) at the height position at the concave bottom that is the most reverse rotation direction. The angle difference between β12 and the inlet angle β14 (see FIGS. 8 and 11) at the blade leading edge tip 4a3 is defined as “angle difference Δβ1”.
Then, as shown in FIG. 17, if the angle difference Δβ1 is too large, peeling occurs on the main plate 2 side of the blade inner peripheral surface 4c and noise deterioration occurs, but the angle difference Δβ1 is “10 ° to 20 °”. If it forms so that it may become between, a low noise effect is acquired.

(Xvi) Note that the shape in which the blade trailing edge portion 4e is curved in a substantially S-shape and the shape in which the blade leading edge portion 4a is curved outward in the radial direction have a low noise effect compared to the conventional case.
Further, by combining both shapes, the suction air flows smoothly from the entire blade leading edge portion 4a, so that a rectified flow flows into the blade trailing edge portion 4e. As a result, since the flow is easy to follow along the surface of the substantially S-shaped blade and the flow with less turbulence flows, the wind speed distribution is also made uniform and the noise reduction is promoted synergistically.

  As described above, the turbofan according to the present invention has low noise and high manufacturing reliability and durability. In addition, by installing such a turbofan, it is possible to guarantee a comfortable use environment by suppressing noise that is unpleasant for the user, and at the same time, it can be used without any trouble over a long period of time. An air conditioner can be provided.

[Embodiment 3: Turbofan]
18 and 19 illustrate a turbofan according to Embodiment 3 of the present invention. FIG. 18 is a perspective view, and FIG. 19 is a sectional view showing a part (more precisely, the blade shown in FIG. 18). It is a longitudinal cross-sectional view of the blade | wing 4 in the plane orthogonal to the chord line D in the main-plate side edge part 4d. In addition, the same code | symbol is attached | subjected to the part which is the same as that of Embodiment 2 (FIGS. 2-12), or respond | corresponds, and one part description is abbreviate | omitted.

In FIG. 18, the front edge inner periphery in the plan view in the range where the front edge side plate side end 4 a 1, which is the edge close to the side plate 3 of the blade 4, is separated from the side plate 3 (same as the range located in the side plate opening). As it approaches the side end 4a2, it is curved so as to be located radially outward, and in a side view, the curve range is enlarged so that it is farther from the end edge as it approaches the front edge inner peripheral side end 4a2.
That is, the turbo fan 30 includes a front plate side end 4a1 of the blade 4 curved outward in the radial direction and a blade outer peripheral surface 4b of the front plate inner peripheral side end 4a2 on the side plate 3 side. A fold line B is gradually generated from the front end 4g1 in the rotational direction of the outer peripheral surface 4b of the blade of the coupling portion 4g toward the front edge inner peripheral side end 4a2 of the blade 4 toward the main plate 2 side.
Further, on the blade inner peripheral surface 4c in such a curved range, a rectangular groove 5 that is substantially perpendicular to the bending line B and extends obliquely outward from the side plate 3 side to the main plate 2 side with respect to the rotation axis O is provided. Is formed.
In FIG. 19, the depth of the concave groove 5 becomes shallower as it approaches the front edge side plate side end 4 a 1.
That is, the blade 4 is formed of a member that forms a blade outer peripheral surface and a member that forms a blade inner peripheral surface, and has a double structure including a cavity therein, both of which are at the leading edge side plate side end 4a1. The distance between the two becomes wider as they are joined and away from the front edge side plate side end 4a1.
And since the groove bottom part 5a of the ditch | groove 5 is formed of the member which forms a blade outer peripheral surface, the depth of the ditch | groove 5 forms the inner peripheral side surface and blade inner peripheral surface of the member which forms a blade outer peripheral surface. This corresponds to the distance from the inner peripheral side surface of the member.

The turbo fan 30 formed in this manner is rotated in the rotation direction A by the fan motor, so that air is sucked from the fan suction port 1a, passes through the blades 4, and then sucked air is rotated from the fan outlet 1b in the rotation direction. Blow out almost radially.
At this time, when the air flows into the blade 4, the leading edge side plate side end portion 4a1 is curved outward in the radial direction, so that the air smoothly flows along the outer peripheral surface 4b of the blade and flows to the trailing edge of the blade. Disturbance is suppressed. Further, since the concave groove 5 is formed so as to extend obliquely while expanding from the side plate 3 side to the main plate 2 side with respect to the rotation axis O, the flow is rectified by the groove bottom portion 5a, so that the disturbance is further disturbed. It is suppressed and noise reduction can be promoted.

Further, since the groove bottom portion 5a of the concave groove 5 is formed along the outer peripheral surface 4b of the blade so that the thickness of the blade 4 is thin, when the turbofan is molded with a thermoplastic resin, the thickness is large. Even the curved portion is thin, so that sink marks can be prevented and the molding reliability is improved.
In particular, when the turbo fan 30 is mounted on the air conditioner 10 (see FIG. 1) in which a pressure loss body such as a filter is disposed in the fan suction port 1a, dust gradually accumulates on the filter and the ventilation resistance is reduced. Even if it increases, peeling can be suppressed and low noise can be maintained.

  Since the present invention has the above-described configuration and low noise and high manufacturing reliability, it is used as various household and commercial turbofans, and as various domestic and commercial air conditioners equipped with such turbofans. Can be widely used.

  DESCRIPTION OF SYMBOLS 1 Turbo fan (Embodiment 2), 1a Fan inlet, 1b Fan outlet, 2 Main plate, 2a Boss, 2b Blade opening, 3 Side plate, 4 Blade, 4a Blade front edge, 4a1 Front edge side plate side of blade End, 4a2 Front edge inner edge side of blade, 4a3 Blade front edge tip, 4ac1 Intersection of blade leading edge 4a and horizontal sled line C1, 4ac2 Intersection of blade front edge 4a and horizontal sled line C21 4ac3 Intersection of the blade leading edge 4a and the horizontal sled line C31, 4ac4 Intersection of the blade leading edge 4a and the horizontal sled line C4, 4b Outer surface of the blade, 4b1 Side plate side attracting portion, 4c Inner surface of the blade, 4d blade main plate side end, 4e blade trailing edge, 4ec1 intersection of blade trailing edge 4e and horizontal sled line C1, 4ec2 intersection of blade trailing edge 4e and horizontal sled line C2, 4ec3 blade trailing edge 4e And horizontal sled lines Crossing point with C3, 4ec4 Crossing point between trailing edge 4e of blade and horizontal sled line C4, 4g side plate joint, 4g1 tip in rotational direction on blade outer peripheral surface of side plate side joint, 5 groove, 5a groove bottom of groove DESCRIPTION OF SYMBOLS 10 Air conditioner (Embodiment 1), 10a Main body top plate, 10b Main body side plate, 10c Main body inlet, 10d Main body outlet, 11 Cosmetic panel, 11a Suction grill, 11b Panel outlet, 12 Filter, 13 Wind direction vane , 14 bell mouth, 15 fan motor, 16 heat exchanger, 17 rooms, 30 turbo fan (Embodiment 2), A rotation direction, B curved reference line, C1 horizontal sled line, C2 vertical sled line, D string line, E1 Tangent line of horizontal sled line C1 at the intersection of horizontal sled line C1 and blade leading edge inner peripheral side end 4a2, E2 Water at intersection of horizontal sled line C1 and blade trailing edge 4e A tangent line of the sled line C1, a tangent line of a circle passing through the intersection of the F1 horizontal sled line C1 and the blade leading edge inner peripheral end 4a2, a tangent line of a circle passing through the intersection of the F2 horizontal sled line C1 and the blade trailing edge 4e, G Straight line connecting main plate side coupling point 4ec1 and side plate side coupling point 4ec4, J suction flow, T blade plane thickness, t thickness, O rotation axis.

Claims (17)

A disc-shaped main plate having a boss which is a fixed portion to which a rotation shaft of the motor is fixed; an annular side plate having a side plate opening at the center which forms a wind guide wall with the main plate; and the main plate and the side plate In a turbofan having a plurality of blades installed across the
In the plan view, the blade is positioned away from the rotation shaft and in the counter-rotating direction as it becomes the blade trailing edge from the blade leading edge,
The blade outer peripheral surface and the blade inner peripheral surface of the blade have a central range in the height direction at the blade leading edge substantially parallel to the rotation axis and a range close to the main plate at the blade leading edge. The turbofan is characterized by having a skirt portion that is inclined so as to be located on the radially outer side of the main plate as it approaches.   The closer to the main plate the blade outer peripheral surface and the blade inner peripheral surface of the blade, the closer to the main plate, the more inclined to be located radially outward of the main plate, The turbofan according to claim 1, wherein the main plate side is curved outward in a radial direction of the main plate. A disc-shaped main plate having a boss which is a fixed portion to which a rotation shaft of the motor is fixed; an annular side plate having a side plate opening at the center which forms a wind guide wall with the main plate; and the main plate and the side plate In a turbofan having a plurality of blades installed across the
In the plan view, the blade is positioned away from the rotation shaft and in the counter-rotating direction as it becomes the blade trailing edge from the blade leading edge,
The blade outer peripheral surface and the blade inner peripheral surface of the blade are such that the central range in the height direction at the blade leading edge is substantially parallel to the rotation axis and the range closer to the main plate is closer to the main plate. It has a skirt that is inclined so as to be located radially outside,
The edge of the blade close to the side plate is joined to the side plate in a range close to the blade trailing edge, located in the side plate opening away from the side plate in a range close to the blade front edge,
The blade trailing edge of the blade is wavy having at least two inflection points located on a virtual cylinder connecting the outer peripheral edge of the main plate and the outer peripheral edge of the side plate, and in a range close to the main plate a main plate side curved portion projecting toward the rotating direction, characterized and to filter Bofan to have a side plate side curved portion projecting in the direction of the rotational direction opposite to the extent of the side plate nearer. A disc-shaped main plate having a boss which is a fixed portion to which a rotation shaft of the motor is fixed; an annular side plate having a side plate opening at the center which forms a wind guide wall with the main plate; and the main plate and the side plate In a turbofan having a plurality of blades installed across the
In the plan view, the blade is positioned away from the rotation shaft and in the counter-rotating direction as it becomes the blade trailing edge from the blade leading edge,
The blade outer peripheral surface and the blade inner peripheral surface of the blade are such that the central range in the height direction at the blade leading edge is substantially parallel to the rotation axis and the range closer to the main plate is closer to the main plate. It has a skirt that is inclined so as to be located radially outside,
In the range where the edge close to the side plate of the blade is located in the side plate opening, a curved range is formed so as to be positioned radially outward as it approaches the blade front edge in a plan view. It said curved range features and to filter Bofan to expand away from the end edge closer to the blade leading edge in. The closer to the main plate the blade outer peripheral surface and the blade inner peripheral surface of the blade, the closer to the main plate, the more inclined to be located radially outward of the main plate, The turbofan according to claim 3 or 4, wherein the main plate side is curved outward in the radial direction of the main plate. A connecting portion between the main plate and the blade trailing edge, the line connecting the coupling portion between the blade trailing edge portion and the side plate of claim 1 to 5, characterized in that parallel to the rotational axis The turbo fan as described in any one. The blade has a hollow structure in which an interval between the blade outer peripheral surface and the blade inner peripheral surface is reduced from the main plate toward the side plate, and has a hollow structure inside. The turbofan as described in any one of Claims 1-6 . In the range where the center line of the blade outer peripheral surface and the blade inner peripheral surface of the blade is joined to the side plate,
Turbofan according to any one of claim 1 to 7, characterized in that parallel to the rotation axis. In a side view of the tip of the trailing edge of the blade, an inclination line connecting the maximum protruding position in the rotation direction of the main plate side bending portion and the maximum protruding position in the direction opposite to the rotation direction of the side plate side bending portion is the main plate and turbofan according to claim 3 or 6, wherein with respect to a vertical line connecting the coupling portion, and wherein the inclined between the inclination angle of 10 ° to 30 ° between the coupling portion and the side plate side. In a plan view of the main plate-side curved portion, a tangent line at a tip of the blade trailing edge of a horizontal warp line indicating the center between the blade outer peripheral surface and the blade inner peripheral surface, and the center of the rotation axis is the center. A tangent to the tip of the blade trailing edge of the circle passing through the tip of the blade trailing edge, and a main plate side exit angle formed by
In a plan view of the side plate side curved portion, a tangent line at a tip of the blade trailing edge of a horizontal warp line indicating the center of the blade outer peripheral surface and the blade inner peripheral surface, and the center of the rotation axis is the center. The angle difference between the tangent at the tip of the blade trailing edge of the circle passing through the tip of the blade trailing edge and the side plate side exit angle formed by the circle is between 20 ° and 35 °. The turbo fan according to 3 or 6 .   A bending angle, which is an angle formed by a tangent line at the tip of the blade leading edge portion of a vertical warp line indicating the center between the blade outer peripheral surface and the blade inner peripheral surface in a side view, and the rotation axis is 25 ° to 45 °. The turbofan according to claim 4, wherein the turbofan is between degrees. At the tip of the leading edge of the blade in plan view,
A side plate side entrance angle that is an entrance angle at a position near the side plate;
Near the blade center entrance angle, which is the entrance angle near the center in the height direction of the side plate and the main plate,
A blade main plate side inlet angle which is an inlet angle at a position near the main plate;
12. The turbo fan according to claim 1, wherein there is a relationship of “blade center vicinity inlet angle> blade main plate side inlet angle> side plate side inlet angle”. At the tip of the leading edge of the blade in plan view,
A blade center inner peripheral inlet angle which is an inlet angle at an end of the inner peripheral side near the center in the height direction of the side plate and the main plate;
A side plate side entrance angle that is an entrance angle at an end near the side plate;
The turbo fan according to claim 12, wherein an angle difference in a plan view of the turbo fan is between 10 ° and 20 °. A concave groove reaching the end near the side plate is formed in the inner peripheral portion of the blade in the curved range of the blade,
A fold line is formed at the boundary between the curved range and the blade inner periphery excluding the curved range,
The turbo fan according to claim 4, wherein the concave groove is substantially perpendicular to the folding line.   The turbo fan according to claim 14, wherein the concave groove has a rectangular cross section and becomes shallower as it approaches an end near the side plate.   An air conditioner equipped with the turbo fan according to any one of claims 1 to 15 and having a pressure loss body capable of passing air to a suction port side of the turbo fan.   An air conditioner equipped with the turbo fan according to any one of claims 1 to 15 and having a pressure loss body capable of ventilating the blower outlet side of the turbo fan.

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