JP2002235695A - Turbo fan, blower using turbo fan, air conditioner - Google Patents

Abstract

(57) [Problem] To provide a turbo fan with high pressure, high ventilation efficiency and low noise, or to save energy and reduce noise in an air conditioner. . SOLUTION: The turbo fan in which a shroud, a hub, and rearwardly facing blades facing in a direction opposite to a plurality of rotation directions are arranged between the shroud, the hub, and a surface of the blade in a direction of the blade wheel rotation direction in a blade height direction. It is formed so as to have a smooth convex shape in the rotation direction near the center from the inner periphery of the impeller, and to have a smooth concave shape in the rotation direction from near the center to the outer periphery of the impeller. From at least near the center to the tip of the impeller outer peripheral side, it is formed to be curved so as to have a smooth concave shape in the rotation direction, and the blade thickness gradually increases from the impeller inner peripheral tip,
Thereafter, the blade has a blade-shaped blade cross section that gradually becomes thinner toward the outer peripheral end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbo fan and an air conditioner using the turbo fan, such as an air conditioner, an air purifier, and a dehumidifier. TECHNICAL FIELD The present invention relates to a turbo fan capable of improving the torsional strength at the time of startup and startup, a blower capable of achieving energy saving, low noise, and the like, and an air conditioner.

[0002]

[Prior art]

According to the document "Takefumi Ikui, Turbo Blower and Compressor, published by Corona Co., Ltd.", a centrifugal fan generally has different names depending on the direction of the blades 2 on the outer peripheral side. This will be described with reference to FIGS.
, A tangent line Mc2 at a point on the outer peripheral end 2b of the arc-shaped sled line 2c which is the center line in the thickness direction of the blade.
An acute angle formed by a straight line Mob passing through the outer peripheral end 2b and passing through the outer peripheral end 2b through the impeller rotation center O and passing through the outer peripheral end 2b is referred to as an exit angle βb2, as shown in FIG. When the outlet angle βb2 is smaller than 90 °, the blade is referred to as a backward facing blade and indicates a turbo fan. Also, as shown in FIG. 60, an object whose outlet angle βb2 is larger than 90 ° and faces in the rotation direction is called a forward facing blade, and is a multi-blade fan (sirocco fan).
Point to. Further, a blade having an outlet angle βb2 of 90 ° as shown in FIG. 61 is referred to as a radial blade and refers to a radial fan.

FIGS. 62 and 63 show an example of a conventional turbofan as a first conventional example. FIG. 62 is a horizontal sectional view of the conventional turbofan, and FIG. 63 is a vertical sectional view of FIG. is there.

In FIGS. 62 and 63, a turbo fan 1
Is composed of an impeller 1a and a motor 3 for driving the impeller 1a.

[0006] The impeller 1 a is provided with a rotating shaft 3 of the motor 3.
a main plate 1b formed integrally with the hub 1c for fixing the
A funnel-shaped shroud 1d facing the main plate 1b to form a guide passage for air to the blades 2, and a plurality of blades 2
Is attached, and the entire impeller 1a rotates.
The shape of the blade 2 is a rearward blade having a substantially uniform thickness t, a uniform thickness, a thin overall shape of the blade 2 with respect to the rotational direction, and an outlet angle βb2 smaller than 90 °.

FIGS. 65, 66, and 67 show another example of a conventional turbofan as a second conventional example.
5 is a horizontal sectional view of a conventional turbofan, and FIG.
FIG. 67 is an enlarged view of one blade 2 of FIG. Note that the same main components of the turbofan 1 as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 65 to FIG. 67, the blade 2 has a thickness t.
However, the thickness t gradually increases from the inner peripheral side tip 2a of the impeller,
Thereafter, the blade 2 has an airfoil shape in which the thickness t gradually decreases toward the outer peripheral end 2b, and the entire blade 2 is curved in a convex shape with respect to the impeller rotation direction A, and the sled line is the center line of the blade 2 in the thickness direction. Similarly, 2c is a backward-facing blade that is formed by a circular arc that is convex in the rotation direction A and has the outlet angle βb2 smaller than 90 °. In addition, in order to improve the performance, the sled line 2c has a convex shape with respect to the rotation direction and a convex shape with respect to the rotation direction. There are a two-arc shape formed and a multi-arc shape in which a sled line is formed by three or more arcs having different radii as shown in FIG. The material of the impeller 1a of the turbo fan is formed of a material obtained by mixing glass fiber and plastic resin.

FIG. 73 shows still another example of a conventional turbofan, which is a third conventional example.
67399 is a perspective view of a range hood fan of 67399, and FIG. 74 is a horizontal sectional view of FIG. Note that the same main components of the turbofan 1 as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. In FIGS. 73 and 74, the blade 2 of the impeller 1a of the turbo fan has a convex shape in the rotation direction A like the turbo fan (rearward blade) on the inner peripheral side, and the rotation direction A of the impeller at the reverse warp start point Ag. , And formed like a forward-facing blade (sirocco fan) having the outlet angle βb2 larger than 90 °.

FIG. 75 is a perspective view of an impeller in which the blade 2 of the conventional turbofan shown in FIG. 65 is hollow and the blade surface is formed in a thin airfoil shape, and FIGS. 76 and 78 are, for example, those of FIG. 76 shows a cross-sectional view of a mounting portion between the blade 2 of the turbo fan and the main plate 1b, FIG. 76 shows a case where the material of the impeller 1a is a resin-based material, and FIGS. 77 and 78 show a mounting structure when the material is a sheet metal such as aluminum. Is shown. In the impeller 1a made of a resin material shown in FIGS. 75 and 76, the mounting portion between the blade 2 and the main plate 1b has a small R shape. When the material is sheet metal, the claws 2e of the blade 2 are connected to the main plate 1 as shown in FIG.
b into the hole 2d, and bend the main plate 1 as shown in FIG.
It was fixed by b and caulking.

FIG. 79 shows an example of a first conventional air conditioner using a turbo fan. For example, a four-way blow-out type ceiling-mounted air conditioner having a main body installed behind the ceiling and four outlets is provided. It is an external view of a machine. FIG. 80 is a vertical sectional view of the air conditioner 100 of FIG. 79, and FIG. 81 is a horizontal sectional view of the air conditioner 100 of FIG. In FIG. 79 to FIG. 81, the air conditioner 100 of the present invention includes an air conditioner main body 101 buried in a ceiling space 108, an impeller 1 a of a turbo fan of a backward blade serving as a blower, and an impeller 1 a. Around a motor 3 for driving, a bell mouth 4, and an impeller 1a of a turbo fan, an air conditioner main body side wall 10 is provided.
A substantially rectangular heat exchanger 103 having a portion parallel to 1a is erected, and a drain pan 104 for receiving drain water as condensed water, an operation of the motor 3 and an angle of the wind direction vane 109 are provided below the heat exchanger 103. An electric component box 106 for accommodating a control board to be mounted is provided.

A decorative panel 102 is fixed to a lower portion of the air conditioner body 101, and a suction port 10 is provided near the center thereof.
2a are formed, and outlets 102b are formed on the four sides on the outside. The turbo fan 1 includes an impeller 1a, an impeller 1a
Bell mouth 4 and impeller 1 that constitute the air guide channel to the air
The motor 3 drives the motor a. The impeller 1a
The main plate 1b integrally formed with the hub 1c for fixing the rotating shaft 3a of the motor 3 is generally oriented in a direction opposite to the impeller rotation direction A as shown in FIGS. On the other hand, an impeller 1 is provided with a funnel-shaped shroud 1d on which a blade 2 which is a convex backward-facing blade is attached, and which faces the main plate 1b and forms a guide passage for air to the blade 2.
a rotates as a whole.

During operation, as shown in FIGS.
The air in the room 107 is sucked by the suction grill 102a by the impeller 1a of the turbo fan which is driven in
After the dust is removed by the filter 105 and passed through the bell mouth 4, the impeller 1a of the turbo fan
Sucked into. Thereafter, the air blown out from the impeller 1a of the turbofan is heated or cooled by the heat exchanger 103, blown out from the blowout port 102b to the room 107, and air-conditioned.

[0014]

A conventional turbo fan,
The air conditioner is configured as described above. In the first conventional turbofan, the shape of the blades 2 is almost uniform and the wall thickness is almost uniform. Therefore, as shown in FIG. 64, when the suction flow F1 fluctuates, the blades 2 are thinner. Peripheral tip 2
a, the pressure fluctuates on each of the surfaces 2P, 2S of the blade 2, and the noise deteriorates. Further, since the blade 2 is thin and has a small installation surface with the main plate 1b and the shroud 1d, when the motor 3 applies a torque to the hub 1c in the rotation direction A by the motor 3 at the time of starting, when the torsion occurs near the main plate 1b of the blade 2 There is a drawback that the strength is weak against torsion and the worst fan is broken.

In the second conventional turbofan, as shown in FIG. 70, the outlet angle βb2 is increased to βb2 ′ at the same position of the inner peripheral tip 2a of the blade 2 and the outlet pressure of the blade 2 is reduced. If the outlet angle βb2 is increased in a convex and curved shape with respect to the impeller rotation direction A as in the conventional method of increasing the air blowing efficiency and improving the air blowing efficiency like the blade 2 ′, However, since the chord length L2 becomes short as L2 ′ and the blade area S (= L2 × B2 (impeller outlet height)) becomes small, there is a disadvantage that the pressure rise becomes small.

An example of the backward-facing blade described with reference to FIG. 59, the first conventional example in which the thickness t of the blade 2 in FIG. 62 is uniform, and the second example in which the blade 2 in FIG. In common with the conventional example, in the rearward-facing vane turbofan, the vanes 2 have a convex shape in the impeller rotation direction A. For example, between the outer peripheral tip 2b of the blade 2 of the turbo fan 1 and the outer peripheral tip 2b 'of the next blade 2' in FIG. 65, that is, the surface 2S of the impeller rotating direction opposite surface 2S of the blade 2 and the next blade 2 '. As shown in FIG. 71 showing the flow velocity distribution between the vehicle rotation direction side surfaces 2P, separation occurs on the outer peripheral side of the rotation direction reverse surface 2S of the blade 2 due to the influence of air viscosity, and the flow velocity becomes slow, so that noise is reduced. There is a disadvantage that it gets worse. Furthermore, the impeller 1 of FIG.
a, near the shroud 1d in the outlet 1e, the main plate 1
The flow velocity is slower and uneven compared to the vicinity of b.

In the third conventional turbofan, since the vicinity of the outer peripheral end 2b of the blade 2 is sharply bent, when a resistance is added to the suction side or the blowout side of the impeller 1a, As shown in FIG. 74, there is a disadvantage that the refracted portion near the outer periphery of the impeller on the surface 2S opposite to the impeller rotation direction of the impeller 2 may be separated, and the noise may be deteriorated.

In the conventional turbo fan, when a torque is applied to the impeller 1a when the motor 3 is started, the force concentrates near the mounting portion of the blade 2 with the main plate 1b. At this time, since the R shape at the attachment portion between the blade 2 and the main plate 1b is small, there is a possibility that the blade 2 is broken at worst. Also, as shown in FIGS. 76 and 78, the impeller rotation direction side surface 2
When the impeller 1a rotates in the rotation direction A near the mounting portion of the P with the main plate 1b and air is pushed out by the blade 2,
A vortex G3 occurs. At this time, since the mounting portion has a small R shape, the vortex G3 circulates in a disturbed state.
It gradually peels off and is a factor of noise deterioration.

In the first conventional air conditioner, when the forward blade and the radial blade as shown in FIGS. 60 and 61 are used, the fan peripheral speed u2 and the fan absolute outflow speed C2 shown in FIGS. Fan peripheral speed u2 and fan absolute outflow speed C2
84, since the outflow angle θ is smaller than the outflow angle θ ′ of the backward-facing blade indicated by the broken line, as in the velocity triangle of the fan blown flow showing the relationship of the outflow angle θ that is the angle formed by each vector. In the state where the angle of attack α with respect to the fins 103a of the heat exchanger of the impeller impingement flow F2 is large, the flow having a high wind speed is directed toward the heat exchanger 103, so that air hardly flows between the fins 103a of the heat exchanger, and As the resistance increases and the noise deteriorates, as shown in FIG. 85, an abnormal noise called Hull-Hul occurs in the frequency region near 2.5 to 5 [KHz] from the fin 103a of the heat exchanger. Compared to a case where no sound is generated, there is a drawback that the frequency characteristics rise and the audibility deteriorates.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and is a turbofan having a large pressure rise, a high ventilation efficiency, a low noise and a high strength, and a high ventilation efficiency and a low noise. It is an object of the present invention to obtain a blower, and an air conditioner that is more energy-efficient, has a better audibility, and has lower noise.

[0021]

According to a first aspect of the present invention, there is provided a main plate extending from the center of rotation to the outer peripheral side of the rotation, a shroud arranged opposite to the main plate to form a gas flow path, and a shroud formed between the main plate and the shroud. In the turbo fan having a blade in which the outlet angle βb2 of the backward facing blade facing in the opposite direction to the plurality of rotation directions disposed between them is 90 ° or less,
The surface of the impeller in the direction of rotation of the impeller has a smooth convex shape in the direction of rotation from the inner periphery of the impeller to the center, and the concave shape in the direction of rotation of the impeller from the center of the impeller to the outer periphery of the impeller. And has an airfoil-shaped blade section that is continuous.

According to a second aspect of the present invention, the surface of the impeller in the direction opposite to the impeller rotation direction has a smooth concave shape in the rotation direction from near the center of the impeller to the outer periphery of the impeller.

According to a third aspect of the present invention, the surface of the impeller in the direction opposite to the impeller rotational direction has a concave shape that is entirely smooth in the rotational direction from the inner peripheral side of the impeller to the outer peripheral side of the impeller.

According to a fourth aspect of the present invention, there is provided a main plate extending from the center of rotation to the outer peripheral side of the rotation, a shroud arranged opposite to the main plate to form a gas flow path, and arranged between the main plate and the shroud. In a turbofan having a blade in which the outlet angle βb2 of the backward blade facing the plurality of rotation directions is 90 ° or less, the warp line of the blade is near the center from the inner periphery side of the impeller of the blade. A circular arc having a convex shape with respect to the rotation direction, and from the vicinity of the center of the blade to an outer peripheral side of the impeller was formed with a circular arc having a concave shape with respect to the rotation direction, and the circular arc was formed by two continuous circular arcs having the same radius. Things.

According to a fifth aspect of the present invention, the warp line of the blade has a reverse warp start point Ag which is an inflection point at which the shape changes from a convex shape to a concave shape in the impeller rotation direction. Ag moves toward the inner periphery of the impeller as it moves from the main plate side in the height direction of the impeller to the shroud side.

According to a sixth aspect of the present invention, the tip of the impeller on the outer periphery side of the impeller moves toward the rotation direction from the main plate side in the impeller height direction toward the shroud side.

According to a seventh aspect of the present invention, a main plate extending from the center of rotation to the outer peripheral side of the rotation, a shroud opposed to the main plate to form a gas flow path, and a shroud are arranged between the main plate and the shroud. In a turbo fan having a blade in which an outlet angle βb2 of a backward blade facing a plurality of rotation directions is 90 ° or less, an airfoil shape in which the entire surface of the blade is concave with respect to the rotation direction It has.

According to an eighth aspect of the present invention, a main plate extending from the center of rotation to the outer peripheral side of the rotation, a shroud opposed to the main plate to form a gas flow path, and a shroud arranged between the main plate and the shroud. In a turbofan having a blade having an outlet angle βb2 of 90 ° or less in a backward direction facing a plurality of rotation directions, an airfoil-shaped blade having a hollow structure, and a mounting in which the blade is mounted on a main plate The size of the radius R of the R shape of the portion is equal to or more than the maximum blade thickness tmax.

According to a ninth aspect of the present invention, there is provided a motor, an impeller rotatably driven by the motor, a suction grill arranged on an air suction side of the impeller, and an air inlet side of the impeller. In the blower including the blowout grill, the impeller is the turbofan according to any one of claims 1 to 8.

According to a tenth aspect of the present invention, there is provided an air conditioner comprising: a blower that sucks and blows indoor air, and a heat exchanger that is disposed on the blowout side of the blower and heats or cools air passing through the blower. Blower is claim 1
8. The turbofan according to any one of 8.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a turbo fan, a blower, and an air conditioner according to the present invention will be described below in detail with reference to the drawings.

Embodiment 1 Hereinafter, a first embodiment of the turbofan according to the first invention will be described with reference to the drawings.
1 is a perspective view of a turbofan of the present invention, FIG. 2 is a longitudinal sectional view of an impeller of the turbofan of FIG. 1, FIG. 3 is a horizontal sectional view taken along line YY of FIG. 2, and FIG. 2 shows an enlarged view of the blade 2 of FIG. In FIG. 1, a turbo fan 1 includes an impeller 1
a, the motor 3.

As shown in FIG. 2, the impeller 1a of the turbofan is disposed so as to face the main plate 1b integrally formed with the hub 1c for fixing the rotating shaft 3a of the motor, and the main plate 1b. A funnel-shaped shroud 1d that forms an air path between the main plate 1b and a plurality of blades 2 is arranged and fixed between the main plate 1b and the shroud 1d, and the entire impeller 1a rotates. Thereby, air is blown from the suction flow F1 to the fan blowing flow F2.

Further, as shown in FIGS. 3 and 4, the sectional shape of the blade 2 is such that the thickness t of the blade 2 is the inner peripheral end 2a of the impeller 1a.
, And gradually becomes thinner toward the outer peripheral tip 2b, and the impeller rotation direction side surface 2P
Is formed so as to be convex in the rotation direction A near the center from the inner peripheral end 2a of the blade 2 and to be concave from the center to the outer peripheral end 2b from the center. Further, the entire surface 2S of the impeller rotation direction opposite side extends in the rotation direction A from the inner peripheral end 2a of the impeller 2 to the outer peripheral end 2b.
The surface 2P of the impeller rotation direction has a larger curvature than the surface 2S of the side opposite to the rotation direction of the impeller. Furthermore, the cross-sectional shape of the blade 2 is substantially the same in the impeller height direction. Also, a straight line O passing through the tangential lines M2P and M2S at the outer circumferential end 2b of the blade 2 on the rotation direction side surface 2P and the rotation direction opposite surface 2S of the blade 2 and the center O of the impeller rotation shaft, and passing through the outer circumferential end 2b. -2b, and the acute angle between each straight line Mob and the straight line Mob passing through the outer peripheral end portion 2b is defined as the rotation-side surface exit angle β.
P2, when the rotation direction reverse surface exit angle βS2, the β
Blade 2 is formed such that P2 and βS2 (βP2 <βS2) are smaller than 90 °. Therefore, the sled line 2c, which is the center line in the thickness direction of the blade 2, is a straight line O- connecting the tangent line Mc2 of the sled line 2c at the blade outer end portion 2b and the impeller rotation shaft center O and the outer peripheral end portion 2b. The rearward blade is perpendicular to 2b and has an exit angle βb2, which is an acute angle formed by the straight line Mob at the outer peripheral end 2b and is smaller than 90 °.

By forming the turbo fan 1 in this manner, since the blades 2 have an airfoil shape, even if the suction flow F1 fluctuates, separation at the inner peripheral end 2a of the impeller is difficult, and low noise is produced. .

As shown in FIG. 3 and FIG. 4, a rotation direction side surface 2P formed in a smooth convex shape with respect to the rotation direction A of the blade 2 near the center from the tip 2a on the inner peripheral side of the impeller, and The curvature is different at the rotation direction opposite surface 2S formed in a smooth concave shape with respect to the rotation direction A, and the rotation direction surface 2P has a larger curvature. Therefore, a flow velocity difference occurs, a pressure difference occurs, and a pressure rise occurs. I can do it. Further, even if the suction flow F1 fluctuates due to the airfoil shape, it is difficult to separate the suction flow F1, so that the pressure can be further increased.

Further, since the surface 2P on the rotation direction side of the blade 2 is curved in a smooth concave shape with respect to the rotation direction A from the vicinity of the center of the blade 2 to the tip 2b on the outer periphery side of the impeller,
The pressure on the outer periphery of the impeller can be increased. Further, since the entire surface 2S on the opposite side in the rotation direction is curved in a smooth concave shape, the separation that occurs on the outer peripheral side of the impeller of the surface 2S due to the viscosity of air is caused when the flow on the surface of the blade 2 is about to separate.
Since the blade 2 is not sharply bent in the rotation direction A as in the conventional turbo fan of FIG. 74, the blade 2 is smoothly deflected by the concave shape of the surface 2S and adheres to the blade surface, so that it is difficult to peel. .

Further, the exit angle βb2 of the blade 2 is increased,
When the pressure at the impeller outlet side of the blade 2 is increased, if the cross-sectional shape of the blade 2 in FIG. 65 which is the conventional turbo fan 1 is a blade shape and the entire blade is convex, the chord length L
2 is sharply shortened, so that the pressure rise in the entire blade 2 becomes small. According to the present invention, the decrease in the chord length L2 is minimal and the outlet angle βb2 can be increased as compared with the conventional turbofan. Therefore, a large increase in pressure can be achieved.

A part or all of the impeller 1a of the turbofan is formed of a magnesium alloy or the like.
Magnesium alloy is a highly recyclable material that has both lightness and robustness in addition to the ease of reproduction that is unique to metals. For this reason, it is more environmentally friendly than conventional ones formed of a mixed material of glass fiber and plastic. Further, even when oil such as a kitchen or a solvent such as a factory becomes a mist and is used in an environment with a high concentration, it has high corrosion resistance.

FIG. 5 is a diagram showing the air blowing characteristics and noise characteristics of a conventional turbo fan whose entire blade 2 is convex and the turbo fan of the present invention. In the figure, the horizontal axis represents the flow coefficient φ, the vertical axis represents the pressure coefficient Δs, and the noise SPL [dBA]. The broken line in the figure indicates the conventional example, and the solid line indicates the characteristics of the present invention. As shown in FIG. 5, the turbo fan of the present invention has higher pressure and lower noise at the same air volume, that is, at the same flow coefficient. For this reason, even if flow path resistance is added to the suction side and the discharge side of the turbo fan 1, low noise and a large air volume can be obtained as compared with the conventional turbo fan. As described above, according to the turbo fan of the present invention, a fan having high pressure, high air volume, low noise, high strength, and high recyclability can be obtained.

Embodiment 2 Hereinafter, a second embodiment which is another example of the turbofan in the first invention will be described with reference to the drawings. FIG. 6 is a perspective view of the turbofan of the present invention,
7 is a longitudinal sectional view of the impeller of the turbo fan of FIG. 6, FIG. 8 is a horizontal sectional view taken along the line YY of FIG. 7, and FIG. 9 is an enlarged view of one blade 2 of FIG. The main configuration of the turbofan of the present invention is the same as that of the first embodiment, and the same portions are denoted by the same reference numerals and description thereof will be omitted.

8 and 9, the cross-sectional shape of the blade 2 is such that the thickness t gradually increases from the inner peripheral end 2a of the impeller 1a, and then gradually decreases toward the outer peripheral end 2b. In the shape, the impeller rotation direction side surface 2P has a smooth convex shape with respect to the rotation direction A from the inner peripheral end 2a of the blade 2 to the vicinity of the center, and the rotation direction A from the center to the outer peripheral end 2b. And the surface 2S on the opposite side in the rotating direction of the impeller is formed with a tip 2a on the inner peripheral side of the blade 2.
From the center to the vicinity of the center, like the blades of the conventional turbofan, has a smooth convex shape in the rotation direction A, and from the vicinity of the center to the outer peripheral end 2b has a smooth concave shape in the rotation direction A unlike the conventional case. The impeller rotation direction side surface 2P formed is larger in curvature than the impeller rotation direction opposite surface 2S. Furthermore, the cross-sectional shape of the blade 2 is substantially the same in the impeller height direction.

Also, straight lines passing through the tangential lines M2P and M2S at the outer peripheral tip 2b of the blade 2 on the rotational direction surface 2P of the blade 2 and the rotational direction opposite surface 2S and the impeller rotation center O and the outer peripheral tip 2b. The acute angle formed by each of the straight line Mob perpendicular to O-2b and passing through the outer peripheral end portion 2b is defined as a rotational direction surface exit angle βP2 and a rotational direction reverse surface exit angle βS2.
In this case, the blades 2 are formed such that βP2 and βS2 (βP2 <βS2) are smaller than 90 °.
Therefore, since the sled line 2c is the center line in the blade thickness direction, the tangent line M of the sled line 2c at the blade outer peripheral end 2b.
A rearward exit angle βb2, which is an acute angle formed by c2 and a straight line Mob at the outer peripheral end 2b, which is perpendicular to a straight line O-2b connecting the impeller rotation center O and the outer peripheral end 2b, is smaller than 90 °. It is a feather.

By forming the impeller 1a of the turbo fan in this way, since the blade 2 has an airfoil shape, even if the suction flow F1 fluctuates, separation at the inner peripheral end 2a of the impeller hardly occurs. It is noise.

As shown in FIGS. 8 and 9, near the center from the tip 2a on the inner peripheral side of the impeller of the impeller 2, the rotational direction side surface 2P and the rotational direction reverse side surface 2S of the impeller 2 become the rotational direction side surface 2P. Has a larger curvature and is formed in a convex shape with a different curvature that is smooth in the rotation direction A, so that a flow velocity difference occurs on each surface, a pressure difference occurs, and a pressure rise can be achieved. Further, even if the suction flow F1 fluctuates due to the airfoil shape, it is difficult to separate the suction flow F1, so that the pressure can be further increased.

Further, since the surface 2P on the rotation direction side of the blade 2 is curved in a smooth concave shape in the rotation direction A from the vicinity of the center of the blade 2 to the tip end 2b on the outer periphery of the impeller,
The pressure on the outer periphery of the impeller can be increased. Further, since the surface 2S on the opposite side to the rotation direction is curved in a smooth concave shape with respect to the rotation direction A, the blade 2 of the conventional turbo fan shown in FIG.
And the following wind speed distribution between the blades 2 ′, the peeling occurs on the outer peripheral side of the impeller on the surface 2 S due to the viscosity of the air, and the wind speed is low.
The present invention deflects and follows the flow to the surface of the vane 2 and reduces separation.

Further, the exit angle βb2 of the blade 2 is increased,
When the pressure at the exit side of the impeller of the blade 2 is increased, in a conventional turbo fan having a blade 2 having a blade-shaped cross-section and the entire blade 2 having a convex shape, as shown in FIG.
When b2 is enlarged, the chord length L2 becomes L like the blade 2 '.
Since the length of the blade 2 suddenly becomes shorter, the pressure rise in the entire blade 2 becomes smaller. According to the present invention, the decrease in the chord length L2 is minimal and the outlet angle βb2 can be increased as compared with the conventional turbofan, so that the pressure rise can be increased.

FIG. 10 is a diagram showing the blowing characteristics and the noise characteristics of a conventional turbo fan whose entire blade 2 is convex and the turbo fan of the present invention. In the figure, the horizontal axis shows the flow coefficient φ, the vertical axis shows the pressure coefficient ψs, and the noise SPL [dBA]. The broken line in the figure shows the conventional example, and the solid line shows the characteristics of the turbofan of the present invention. As shown in FIG. 10, the turbo fan of the present invention has the same air volume, that is, the same flow coefficient, the higher pressure, and the lower noise. For this reason, even if airflow resistance is added to the suction side or the blowout side of the turbofan 1, low noise and a large air volume can be obtained as compared with a conventional turbofan.

As described above, Embodiment 1. And 2. Thus, the cross-sectional shape of the blade 2 is such that the thickness t is the inner peripheral end 2 of the impeller 1a.
a, and gradually becomes thinner toward the outer peripheral end 2b.
Is formed in a smooth convex shape in the rotation direction A from the inner peripheral end 2a of the blade 2 to the vicinity of the center, and is formed in a smooth concave shape in the rotational direction A from the center to the outer peripheral end 2b. The surface 2S on the opposite side of the impeller rotation direction is formed in a smooth concave shape with respect to the rotation direction A from at least the vicinity of the center of the blade 2 to the outer peripheral end 2b, so that the suction side or the discharge side of the turbo fan 1 is formed. Even if resistance is added, noise and a large air volume can be obtained as compared with the conventional turbo fan.

Embodiment 3 Hereinafter, a third embodiment of the turbofan according to the second invention will be described with reference to the drawings. FIG. 11 is a longitudinal sectional view of the turbofan of the present invention, and FIG.
1 is a horizontal sectional view taken along the line YY, and FIG. 13 is an enlarged view of one blade of FIG. The main configuration of the turbofan of the present invention is the same as that of the first embodiment, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIGS. 11, 12, and 13, the sectional shape of the blade 2 is such that the thickness t gradually increases from the inner peripheral end 2a of the impeller 1a, and then gradually decreases toward the outer peripheral end 2b. A curved line 2c, which is a center line in the thickness direction of the blade 2 and has a radius R that is convex with respect to the rotation direction A from the tip 2a on the inner peripheral side of the impeller to the vicinity of the center. In the line 2c1), up to the outer peripheral end 2b, the same radius R as the warped line 2c1 having a concave shape with respect to the rotation direction A.
(The sled line 2c2). That is, the warp line 2c of the blade 2 of the present invention is not a single circular arc having a convex shape in the rotation direction A like the warp line 2c of the conventional turbofan in FIG. On the other hand, convex,
It is formed by two concave arcs of the same radius R.

Further, the shape of the surface of the blade 2 is such that the surface 2P on the impeller rotation direction side has a smooth convex shape in the rotation direction A from the inner peripheral tip 2a of the blade 2 to the vicinity of the center, and from the vicinity of the center. Up to the outer peripheral side tip 2b, a smooth concave shape is formed in the rotation direction A, and the impeller rotation direction opposite surface 2 is formed.
S is the rotation direction A from the inner peripheral end 2a of the blade 2 to the vicinity of the center, similarly to the conventional turbofan blade of FIG.
Smooth convex shape from the center to the outer end 2
Up to b, unlike the conventional case, it is formed in a smooth concave shape with respect to the rotation direction A, and the impeller rotation direction side surface 2P has a larger curvature than the impeller rotation direction opposite surface 2S. Furthermore, the cross-sectional shape of the blade 2 is substantially the same in the impeller height direction. The blade 2 has a hollow inside and a thin airfoil shape.

Further, the outer peripheral side warpage line 2c of the blade 2
A tangent line Mc2 at the outer peripheral end 2b of the second blade 2 and a straight line O- connecting the impeller rotation axis center O and the outer peripheral end 2b.
2b, a line Mo perpendicular to the outer peripheral end 2b.
The rearward blade has an exit angle βb2, which is an acute angle with b, smaller than 90 °.

By forming the impeller 1a of the turbo fan in this way, since the blade 2 has an airfoil shape, even if the suction flow F1 fluctuates, it is difficult for the impeller inner peripheral end 2a to peel off. It is noise.

As shown in FIGS. 11, 12, and 13, near the center from the tip 2a on the inner peripheral side of the impeller of the impeller 2, the rotational direction side surface 2P and the rotational direction opposite side surface 2P of the impeller 2 are arranged.
In S, the rotation direction side surface 2P has a larger curvature and is formed in a convex shape with a smooth different curvature in the rotation direction A, so that a pressure difference is generated due to a flow velocity difference on each surface, and a pressure rise occurs. Can be achieved. Further, even if the suction flow F1 fluctuates due to the airfoil shape, it is difficult to separate the suction flow F1, so that the pressure can be further increased.

Further, since the surface 2P on the rotation direction side of the blade 2 is curved in a smooth concave shape in the rotation direction A from the vicinity of the center of the blade 2 to the tip 2b on the outer periphery side of the impeller,
The pressure on the outer periphery of the impeller can be increased. Further, since the surface 2S on the opposite side in the rotating direction is curved in a smooth concave shape with respect to the rotating direction A, in the conventional turbo fan of FIG. 67, the surface 2S is separated on the outer peripheral side of the impeller due to the viscosity of air. Although the wind speed is reduced, the present invention deflects the flow to the surface of the blade 2 so as to follow it, and the separation is eliminated.

Here, as shown in FIG. 70, in a conventional turbo fan in which the cross-sectional shape of a blade having a curved line 2c is a circular arc and the entire blade 2 is convex, the exit angle βb2 of the blade 2 To increase the pressure of the blade 2 at the impeller outlet side, the blade 2 is made to have an outlet angle βb2 like the blade 2 ′.
Is expanded to βb2 ′, the chord length L2 is sharply shortened to L2 ′, and the pressure rise in the entire blade 2 is reduced. The tangent line Mc1 at the blade inner peripheral end 2a of the sled line 2c and the straight line O-2a passing through the blade inner peripheral end 2a passing through the center of the impeller rotation shaft O are perpendicular to the inner peripheral end 2a.
When the entrance angle βb1 is defined as an acute angle formed by the straight line Moa passing through a and the exit angle βb2, the entrance angle βb1 becomes β
It expands to b1 '. Therefore, even when the cross-sectional shape of the blade 2 is an airfoil shape, the angle of attack with the suction flow F1 increases, and separation occurs at the inner peripheral end 2a, thereby deteriorating noise.

Further, the warp line 2c in FIG.
In the case of the conventional turbofan formed by two arcs having different radii R1 and R2 having different convex shapes, the conventional sled line 2c in FIG. 67 has the most suitable shape of the blade 2 for the flow as compared with the single-arc turbofan. However, if the exit angle βb2 is increased while maintaining a convex shape with respect to the rotation direction A, the chord length L2 is also sharply shortened, so that the pressure rise in the entire blade 2 is reduced. Further, the different radii R of FIG.
In the case of a conventional turbofan having three arc-shaped sled lines 2c of 1, R2, and R3, the shape of the blade 2 can be further optimized for the flow as compared with the two-arc-shaped sled line 2c. Many arcs complicate the design.

According to the present invention, since the decrease in the chord length L2 is minimal and the exit angle βb2 can be increased, the pressure rise due to the decrease in the chord length L2 as in the conventional turbo fan 1 can be minimized. In addition, since the outlet pressure can be greatly increased, the pressure rise of the blade 2 as a whole can be increased. Also, the design of the sled line 2c is formed by two arcs having the same radius R that are uneven in the rotation direction, and the shape is simple, so that the design is easy.

FIG. 14 is a diagram showing the airflow characteristics and noise characteristics of a conventional turbofan whose entire blade 2 is convex and the turbofan of the present invention. In the figure, the horizontal axis shows the flow coefficient φ, the horizontal axis shows the pressure coefficient ψs, and the noise SPL [dBA]. The broken line in the figure shows the conventional example, and the solid line shows the characteristics of the turbofan of the present invention. As shown in FIG. 14, the turbo fan of the present invention has a higher pressure and a higher air volume.

FIG. 15 shows a conventional turbo fan in which the entire blade 2 has a convex shape, and an air flow Q [m ³ / m] of the turbo fan of the present invention.
FIG. 7 is a diagram showing a relationship between noise values SPL [dBA] at the time of change of [min]. In the figure, the horizontal axis represents the airflow Q [m ³ / min], the vertical axis represents the noise value SPL [dBA], and the broken line in the figure represents the characteristics of the conventional and the solid line represents the characteristics of the turbofan of the present invention. As shown in FIG. 15, the turbo fan of the present invention has lower noise at the same air volume.

As described above, the turbofan of the present invention
Compared with the conventional turbo fan, a high pressure and a high air volume can be obtained, so that even if resistance is added to the suction side and the air discharge side of the impeller 1a, the air flow is small and the noise is low.

Embodiment 4 Hereinafter, a fourth embodiment of the turbofan according to the third invention will be described with reference to the drawings.
FIG. 16 is a perspective view of the turbofan of the present invention, and FIG.
6 is a longitudinal sectional view of the impeller of the turbo fan of FIG.
19 is an enlarged view of one blade 2 in FIG. 18. The main configuration of the turbofan of the present invention is the same as that of the first embodiment, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIGS. 18 and 19, the cross-sectional shape of the blade 2 of the turbofan of the present invention is such that the thickness t of the blade 2 is almost uniformly equal and thin, and the entire blade 2 with respect to the impeller rotation direction A. Are concavely curved. Further, a tangent line Mc2 of the sled line 2c, which is the center line in the blade thickness direction, at the blade outer peripheral end 2b, the impeller rotation center O, and the outer peripheral end 2b
The exit angle βb2, which is an acute angle formed by a straight line Mob perpendicular to the straight line O-2b connecting the
A backward-facing blade smaller than ゜.

By forming the turbo fan impeller 1a in this manner, the distance between the outer peripheral tip 2b of the blade 2 of the turbo fan 1 and the outer peripheral tip 2b 'of the next blade 2' in FIG. As shown in the flow velocity distribution diagram in FIG. 20, the flow on the blade rotation direction side surface 2P side having a particularly high flow velocity can be further increased as shown by the solid line in the blowout wind velocity distribution diagram of FIG. Can be further increased, so that the pressure rise can be increased.

FIG. 21 is a diagram showing the air blowing characteristics and noise characteristics of a conventional turbo fan and a turbo fan of the present invention in which the thickness t of the blade 2 is uniform and thin and the entire blade 2 is convex. is there. In the figure, the horizontal axis represents the flow coefficient φ, and the vertical axis represents the pressure coefficient ψ.
Taking s and noise SPL [dBA], a broken line in the figure indicates a conventional example, and a solid line indicates characteristics of the present invention. As shown in FIG.
Since the turbo fan of the present invention has a high pressure and a high air volume, it has high air blowing efficiency and low noise.

Embodiment 5 Hereinafter, a fifth embodiment which is another example of the turbofan in the third invention will be described with reference to the drawings. FIG. 22 is a perspective view of the turbo fan of the present invention, FIG. 23 is a horizontal sectional view of FIG. 22, and FIG. 24 is an enlarged view of one of the blades 2 of FIG. The main configuration of the turbofan of the present invention is the same as that of the first embodiment, and the same or corresponding portions are denoted by the same reference characters and description thereof will be omitted.

As shown in FIGS. 23 and 24, the cross-sectional shape of the blade 2 is such that the thickness t of the blade 2 gradually increases from the inner peripheral end 2a of the impeller 1a, and then gradually decreases toward the outer peripheral end 2b. It has an airfoil shape, and the curvature is different between the rotation direction surface 2P and the rotation direction opposite surface 2S, and the rotation direction opposite surface 2S
Has a larger curvature.

Further, the entire blade 2 is curved in a concave shape in the rotation direction A of the impeller. The tangent line Mc2 of the sled line 2c, which is the center line in the thickness direction of the blade, at the blade outer peripheral end 2b, the impeller rotation center O, and the outer peripheral end 2b
The exit angle βb2 which is perpendicular to the straight line O-2b and the acute angle formed by the straight line Mob at the outer peripheral end 2b is 9
A rearward vane smaller than 0 °.

By forming the impeller 1a of the turbo fan in this manner, the distance between the outer end 2b 'of the blade 2 of the conventional turbo fan 1 and the outer end 2b' of the next blade 2 'in FIG. As shown in the flow velocity distribution diagram, the flow on the blade rotation direction side surface 2P having a high flow velocity can be further increased in speed as shown in FIG. 25, and the velocity difference with the rotation direction opposite side surface 2S can be further increased. Since the shape is an airfoil shape, even if the suction flow F1 fluctuates, it is difficult to cause separation at the inner peripheral end portion 2a of the blade 2, so that the pressure can be increased more.

FIG. 26 is a view showing the air blowing characteristics and the noise characteristics of a conventional turbo fan in which the blade 2 has an airfoil shape and the entire blade 2 is convex, and the turbo fan of the present invention. In the figure, the horizontal axis represents the flow coefficient φ, and the vertical axis represents the pressure coefficient ψs and the noise SP.
Taking L [dBA], the broken line in the figure indicates the characteristics of the related art, and the solid line indicates the characteristics of the present invention. As shown in FIG. 26, with the turbo fan of the present invention, since the air pressure is high and the air volume is high, the air blowing efficiency is further higher.

Embodiment 6 FIG. Hereinafter, a sixth embodiment of the turbofan according to the fourth invention will be described with reference to the drawings. FIG. 27 is a horizontal sectional view of the turbofan of the present invention, and corresponds to FIG. 12 of the third embodiment. FIG. 28 is a cross-sectional view of the vicinity of the main plate 1b at KK of the blade 2 of the turbofan of FIG. FIG. 29 is a view showing an example of another shape of the attachment portion between the blade 2 and the main plate 1b, and FIGS.
FIG. 4 is a mounting cross-sectional view showing an example of mounting the blades 2 and the main plate 1b when the material of the turbofan is a sheet metal such as aluminum or iron plate. The main configuration of the turbofan of the present invention is as follows.
This is the same as the first embodiment, and the same or corresponding parts are denoted by the same reference characters and description thereof will be omitted.

As shown in FIG. 27, the cross-sectional shape of the blade 2 has an airfoil shape in which the thickness t of the blade 2 gradually increases from the inner peripheral end 2a of the impeller 1a, and then gradually decreases toward the outer peripheral end 2b. In addition, the entire blade 2 is curved in a convex shape in the impeller rotation direction A. Further, the blade 2 has a hollow structure, and a rotation direction side surface 2P and a rotation direction opposite side surface 2S are formed of a thin resin material, and as shown in FIG.
An attachment portion between the main plate 1b and the main plate 1b is integrally formed in an R shape having a radius as large as the maximum thickness tmax of the blade 2.

By forming the impeller 1a of the turbo fan in this manner, the blade 2 and the main plate 1 shown in FIG.
In the turbo fan having a small R at the mounting portion b, the force due to the torque applied to the impeller 1a when the motor 3 is started is concentrated on the mounting portion, and the worst blade 2 is not damaged. Strength is improved. As shown in FIG. 29, even if the inner surface of the hollow structure of the blade 2 is substantially at an angle, at least the surface of the blade 2 and the mounting portion of the main plate 1b have an R-shape whose radius is the dimension of the maximum thickness tmax. , The strength is improved.

Further, when the material of the impeller of the turbo fan is a sheet metal such as aluminum, iron plate or the like, FIG.
7, as shown in FIG. 78, the main plate 1b has a hole 2d for inserting the small claw 2e of the blade 2 in advance, and after the insertion, the claw 2e is bent in a small R shape and fixed with the main plate 1b by swaging. Stress was concentrated on the claws 2e. As shown in FIG. 30, the entire mounting portion of the main plate 1b of the blade 2 is formed into a bent R shape larger than the maximum blade thickness tmax, so that the mounting surface of the main plate 1b and the blade 2 is increased and stress concentration can be avoided. Therefore, the strength is improved. As another example, as shown in FIG. 31, even if the main plate 1b is flat, the strength is improved because the mounting portion of the blade 2 has a large R shape.

It should be noted that even if the impeller 1a of the turbofan described in the first to fifth embodiments is formed in the same manner as in the present embodiment, the strength can be improved.

Embodiment 7 Hereinafter, a seventh embodiment of the turbofan according to the fifth invention will be described with reference to the drawings.
FIG. 32 is a perspective view of the turbofan of the present invention, and FIG.
34, FIG. 34 is a horizontal sectional view along Z1-Z1 in FIG. 33, and FIGS. 35 to 37 are Z3-Z3, Z in FIG.
2 shows enlarged views of one blade 2 in 2-Z2 and Z1-Z1. The main configuration of the turbofan of the present invention is the same as that of the first embodiment, and the same or corresponding portions are denoted by the same reference characters and description thereof will be omitted.

As shown in FIGS. 34 to 37, the cross-sectional shape of the blade 2 is such that the thickness t of the blade 2 gradually increases from the inner peripheral end 2a of the impeller 1a, and then gradually decreases toward the outer peripheral end 2b. In the airfoil shape, the rotation direction side surface 2P and the rotation direction opposite side surface 2S have different curvatures, and the rotation direction side surface 2P has a larger curvature.

The Z of the blade 2 near the main plate 1b in FIG.
FIG. 37 is a sectional view taken along line 3-Z3, FIG. 37 is a sectional view taken along line Z2-Z2 near the center of the impeller outlet 1e in the height direction, and FIG.
As shown in the cross-sectional view along Z1-Z1 of the blade 2 in the vicinity of the shroud 1d, the sled lines 2c1, 2c2, and 2c3 that are the center lines of the blade 2 in the thickness direction of the blade are formed by the respective impellers 1a.
In the height direction of the impeller 1a (the sled line 2c).
31, 2c21, 2c11), the outer side (warp lines 2c32, 2c22, 2c12) are concave, and the inner and outer sled lines 2c have the same radius R. .

The tip 2b on the outer periphery of the blade of the sled line 2c
Is perpendicular to a straight line O-2b connecting the impeller rotation center O and the outer peripheral end 2b, and an exit angle βb2, which is an acute angle formed by a straight line Mob at the outer peripheral end 2b, is greater than 90 °. A small backward-facing wing. Further, in the present embodiment, the positions of the inner peripheral end 2a and the outer peripheral end 2b of the blade 2 are in the height direction of the impeller 1a.
They are formed to be the same. Therefore, the exit angle β
b2 and the chord length L2 are formed to be the same in the impeller height direction.

Then, at a point on the sled line 2c, the sled line 2c
The inflection point at which the blade begins to turn concavely with respect to the impeller rotation direction A is the reverse warp start point Ag, the chord length L2 which is the length of the chord L0 of the blade 2, and the perpendicular from the reverse warp start point to the chord L0. And chord L0
In the height direction of the air outlet 1e of the impeller 1a, the inflection point Ag is located at a distance from the main plate 1b to the shroud 1d.
, The blade 2 is formed so as to linearly move in the height direction of the impeller from the outer peripheral side of the impeller 2 to the inner peripheral side. That is, assuming the intersection Mg of the vertical line from the reverse warp start point Ag to the chord L0 and the chord, and the distance Lg from the blade inner peripheral side tip 2a at the intersection Mg, the ratio Lg / L2 is the main plate 1
It is formed so that it becomes smaller from b to the shroud 1d.

By forming the impeller 1a of the turbofan of the present invention in this way, the blade 2 has a blade shape, so that even if the suction flow F1 fluctuates, the impeller inner peripheral end 2a
It is hard to cause peeling in a and low noise.

Then, as shown in FIG. 35 to FIG.
Near the center from the tip 2a on the inner peripheral side of the impeller.
The rotation direction side surface 2P and the rotation direction reverse side surface 2S have a larger curvature in the rotation direction side surface 2P, and are formed in a convex shape with a different curvature smoothly in the rotation direction A.
A flow velocity difference occurs on each surface, a pressure difference occurs, and a pressure rise can be achieved. Further, even if the suction flow F1 fluctuates due to the airfoil shape, it is difficult to separate the suction flow F1, so that the pressure can be further increased.

Also, since the surface 2P on the rotation direction side of the blade 2 is curved in a smooth concave shape in the rotation direction A from the vicinity of the center of the blade 2 to the tip end 2b on the outer periphery of the impeller,
The pressure on the outer periphery of the impeller can be increased. Further, since the surface 2S on the opposite side in the rotation direction is curved in a smooth concave shape with respect to the rotation direction A, in the conventional turbo fan of FIG. According to the present invention, the flow is deflected to the surface of the blade 2 so as to follow the surface, and the separation is eliminated.

As shown in FIG. 72, as shown in the blow-off air velocity distribution in the height direction of the impeller 1a of the conventional turbo fan 1, the shroud 1
Although the wind speed in the vicinity of d is lower than that in the vicinity of the main plate 1b, the warp line 2c starts to turn concavely with respect to the impeller rotation direction A in the height direction of the impeller 1a as in the present invention. As the curved point Ag moves from the vicinity of the main plate 1b to the vicinity of the shroud 1d, it moves toward the inner peripheral side of the impeller 1a. Therefore, the curvature of the blade 2 on the outer peripheral side of the impeller is smaller than that of the main plate 1b.
Since the d-side is larger, the wind speed near the shroud 1d increases.

As a result, as shown in the wind speed distribution diagram of FIG. 38, which shows the variation of the blowing air speed at the blowing outlet 1e in the height direction of the impeller a with respect to the average, the inflection point Ag indicated by the broken line changes in the blowing distribution at a constant time. In comparison, the present invention is more uniform.

Further, as shown in FIG. 39 showing the change in the noise value when the air volume changes, even when an obstacle is installed near the outlet 1e of the impeller, the timing at which the air is blown out in the height direction of the impeller changes. However, the noise value at the same airflow Q0 [m ³ / min] is lower than that of the case where the inflection point of the blade 2 is fixed.
Therefore, it is possible to obtain a turbofan with high total pressure, low noise, and improved blowout distribution.

Embodiment 8 FIG. Hereinafter, an eighth embodiment which is another example of the turbofan according to the fifth invention will be described with reference to the drawings. 40 is a perspective view of the turbofan of the present invention, FIG. 41 is a longitudinal sectional view of FIG. 40, FIG. 42 is a horizontal sectional view of Z1-Z1 near the center of the outlet 1e of FIG. 41, and FIGS. Are Z3-Z3 and Z in FIG. 41, respectively.
2 shows enlarged views of one blade 2 in 2-Z2 and Z1-Z1. The main configuration of the turbofan of the present invention is the same as that of the first embodiment, and the same or corresponding portions are denoted by the same reference characters and description thereof will be omitted.

As shown in FIGS. 42 to 45, the cross-sectional shape of the blade 2 is such that the thickness t of the blade 2 gradually increases from the inner peripheral end 2a of the impeller 1a in the height direction of the impeller 1a. Thereafter, it has an airfoil shape that gradually becomes thinner toward the outer peripheral end 2b, and the rotational direction side surface 2P and the rotational direction opposite side surface 2S have different curvatures, and the rotational direction side surface 2P has a larger curvature.

The Z of the blade 2 near the main plate 1b in FIG.
FIG. 45 is a sectional view taken along line 3-Z3, FIG. 45 is a sectional view taken along line Z2-Z2 near the center of the impeller outlet 1e in the height direction, and FIG.
As shown in the sectional view along Z1-Z1 of the blade 2 in the vicinity of the shroud 1d, the sled line 2c which is the center line of the blade 2 in the thickness direction of the blade 2 is located at the height of the impeller 1a. Inner circumference side (sled lines 2c11, 2c21,
2c31) has a convex shape and the outer peripheral side (2c12, 2c2).
2, 2c32), the blades 2 are formed so as to have a concave shape.

Further, the tip 2b on the outer peripheral side of the blade of the sled line 2c
Is perpendicular to a straight line O-2b connecting the impeller rotation center O and the outer peripheral end 2b, and an exit angle βb2, which is an acute angle formed by a straight line Mob at the outer peripheral end 2b, is greater than 90 °. A small backward-facing wing.

Then, at a point on the sled line 2c, the sled line 2c
The inflection point at which the blade begins to turn concavely with respect to the impeller rotation direction A is the reverse warp start point Ag, the chord length L2 which is the length of the chord L0 of the blade 2, and the perpendicular from the reverse warp start point to the chord L0. And chord L0
In the height direction of the air outlet 1e of the impeller 1a, the inflection point Ag is located at a distance from the main plate 1b to the shroud 1d.
, The blade 2 is formed so as to linearly move in the height direction of the impeller from the outer peripheral side of the impeller 2 to the inner peripheral side. That is, the intersection Mg of the perpendicular to the chord L0 from the reverse warp start point and the chord, and the tip 2a on the inner periphery side of the blade at the intersection Mg
When the distance from the main plate 1b to the shroud 1d, the ratio Lg / L2 is formed to be smaller. In the present embodiment, the position of the outer peripheral side tip 2d of the blade 2 is, as shown in the perspective view of FIG. 40, in the height direction of the impeller 1a from the main plate 1b to the shroud 1d.
, It is formed so as to move toward the impeller rotation direction. For this reason, the exit angle βb2 in the height direction of the impeller is formed so as to increase from the main plate 1b side of the blade 2 toward the shroud 1d side (βb
23 <βb22 <βb21).

By forming the impeller 1a of the turbo fan of the present invention in this manner, the blade 2 has a blade shape, so that even if the suction flow F1 fluctuates, the tip 2 on the inner peripheral side of the impeller is formed.
It is hard to cause peeling in a and low noise.

Then, as shown in FIG. 43 to FIG.
Near the center from the tip 2a on the inner peripheral side of the impeller.
The rotation direction side surface 2P and the rotation direction reverse side surface 2S have a larger curvature in the rotation direction side surface 2P, and are formed in a convex shape with a different curvature smoothly in the rotation direction A.
A flow velocity difference occurs on each surface, a pressure difference occurs, and a pressure rise can be achieved. Further, even if the suction flow F1 fluctuates due to the airfoil shape, it is difficult to separate the suction flow F1, so that the pressure can be further increased.

Further, since the surface 2P on the rotation direction side of the blade 2 is curved in a smooth concave shape in the rotation direction A from the vicinity of the center of the blade 2 to the tip 2b on the outer peripheral side of the impeller,
The pressure on the outer periphery of the impeller can be increased. In addition, since the surface 2S on the opposite side in the rotation direction is curved in a smooth concave shape with respect to the rotation direction A, in the turbo fan shown in FIG. According to the present invention, the separation occurring on the outer peripheral side is deflected to the surface of the blade 2 so as to follow the flow, and the separation is eliminated.

Then, as shown in FIG. 72, the blowout speed in the height direction of the impeller 1a of the conventional turbo fan 1 is different from the shroud 1 at the outlet 1e of the impeller 1a.
Although the wind speed in the vicinity of d is lower than that in the vicinity of the main plate 1b, the warp line 2c starts to turn concavely with respect to the impeller rotation direction A in the height direction of the impeller 1a as in the present invention. As the curved point Ag moves from the vicinity of the main plate 1b to the vicinity of the shroud 1d, it moves toward the inner peripheral side of the impeller 1a. Therefore, the curvature of the blade 2 on the outer peripheral side of the impeller is smaller than that of the main plate 1b.
Since the d-side is larger, the wind speed near the shroud 1d increases.

As a result, as shown in the wind speed distribution diagram of FIG. 46, which shows the variation of the blown air speed at the outlet 1e in the height direction of the impeller a with respect to the average, the inflection point (reverse warping start point) indicated by the broken line in the drawing. In the third embodiment in which Ag is constant, the outlet wind speed distribution and the inflection point (reverse warp start point) Ag change, but the position of the blade outer peripheral tip 2b is the same in the impeller height direction in the seventh embodiment. Compared with the distribution, the turbo fan of the present invention shown by the solid line has a more uniform wind speed distribution. In FIG. 46, the horizontal axis represents the position in the height direction of the impeller, and the vertical axis represents the blowing wind speed [m
/ S]. Further, since the blowing timing changes, noise is reduced as shown in the noise frequency characteristic diagram at the same air volume shown in FIG. FIG. 47 shows the case where the horizontal axis represents frequency [kHz] and the vertical axis represents noise level [dBA], and the upper characteristic value in the characteristic diagram is fixed (constant) at the inflection point (reverse warping start point) Ag. , The lower characteristic value in the eighth embodiment. Therefore, it is possible to obtain a turbo fan with high pressure, high air flow, low noise, and improved blowout distribution.

Embodiment 9 FIG. Hereinafter, a ninth embodiment of a blower according to the sixth invention will be described with reference to the drawings. FIG.
8 is a schematic view of the installation of the blower of the present invention, FIG. 49 is a longitudinal sectional view of the blower of FIG. 48, and FIG. 50 is a horizontal sectional view taken along line YY of FIG.

In FIG. 48, the blower 200 of the present invention
Is installed in a state where the blower main body 201 is suspended from the ceiling 112, and a suction grill 2 is provided below the blower main body 201.
In the side wall 201a of the blower main body 201, four outlets 203 are formed.

In FIGS. 49 and 50, the blower main body 201 is formed of a side wall 201a and a top plate 201b, and guides air to the turbo fan 1 composed of the impeller 1a and the motor 3 and the impeller 1a. It is composed of a bell mouth 4 forming a flow path. And the impeller 1a of the turbo fan
Uses, for example, the impeller 1a of the turbo fan described in the first embodiment.

In such a blower 200, during operation, the air in the room 107 sucked from the suction grill 202 is sucked into the turbo fan impeller 1 a after the dust and the like in the room are removed by the filter 105. Thereafter, the air is blown out again from the air outlet 203 toward the entire room 107 to circulate the air in the room 107.

By configuring the blower 200 in this manner, the impeller 1a of the turbo fan has a higher pressure, a higher air volume, and lower noise than the conventional turbo fan. Since the air flow rate is large and the amount of blown air is large, air in a low place in the room 107 is also sucked in. As shown in FIG. Since the circulation of the air in the room 107 is further promoted, the temperature difference ΔTa between the vicinity of the room floor and the vicinity of the room ceiling at the time after the start of operation in FIG. The temperature unevenness of the air in the room 107 can be reduced. In FIG. 52, the vertical axis represents the temperature difference ΔTa [° C.] between the vicinity of the floor and the ceiling of the room, and the horizontal axis represents time [min].
, The solid line in the figure indicates the conventional case, and the broken line indicates the case of the present invention.

Embodiment 10 FIG. Hereinafter, an air conditioner according to a tenth embodiment of the present invention will be described with reference to the drawings. For example, a four-way blow-out ceiling embedded air conditioner in which a main body is installed behind the ceiling and has four outlets is shown, FIG. 53 is an external view of the air conditioner, FIG. 54 is a longitudinal sectional view of FIG.
5 is a horizontal sectional view of FIG.

53 to 55, in the air conditioner of the present invention, the main body 101 is embedded in the ceiling 108.
In the lower part of the air conditioner body 101, there is a suction port 1 near the center.
02a, a decorative panel 102 having an air outlet 102b is fixed to the outside four sides, and the decorative panel 102 is installed so as to be visible from the room 107. Thereby, at the time of operation, the air conditioner body 1
After the air in the room 107 is sucked into the room 01, the air is blown from the four outlets 102b toward the entire room 107 after the air conditioning.

In FIGS. 54 and 55, the casing of the air conditioner main body 101 is formed by an upper ceiling plate 101b and a side wall 101a attached around the upper ceiling plate 101b.
Inside the air conditioner main body 101 buried in 8, an impeller 1a of a turbo fan of a backward-facing blade as a blower, a motor 3 for driving the impeller 1a, a bell mouth 4, and an impeller 1a of a turbo fan Around the air conditioner main body side wall 101a, a substantially rectangular heat exchanger 10 having a parallel portion.
In the lower part of the heat exchanger 103, there are disposed a drain pan 104 for receiving drain water as condensed water, an electric box 106 for accommodating a control board for controlling the operation of the motor 3 and the angle of the wind direction vane 109, and the like. Is established.

The turbo fan 1 includes an impeller 1a, an impeller 1
The motor 3 drives the motor a. This impeller 1a
Is mounted on a main plate 1b integrally formed with a hub 1c for fixing a rotating shaft 3a of the motor 3, for example, in the third embodiment. As the warp line 2c of the blade 2 goes from the inner circumference to the outer circumference of the impeller, the blade 2 in the form of a backward-facing blade having two arcs of the same radius that are convex and concave with respect to the rotation direction A is attached to the main plate 1b. Is formed by a funnel-shaped shroud 1d which forms a guide passage for air to the blades 2 facing the blades 1.
a rotates as a whole.

At the time of operation, as shown in FIGS. 54 and 55, the air in the room 107 is sucked by the impeller 1a of the turbo fan which is driven by the motor 3 and rotates in the direction of arrow A.
a, and after the dust or the like is removed by the filter 105, the dust passes through the bell mouth 4 and passes through the impeller 1 of the turbo fan.
sucked into a. After that, the turbo fan impeller 1a
The air blown out from is heated or cooled by the heat exchanger 103, blown out from the outlet 102b to the room 107, and air-conditioned.

The turbo fan 1 of the present invention mounted in such a four-way blow-out ceiling embedded type air conditioner has the following features.
Compared with the conventional turbo fan, the pressure is higher, the air flow is higher, and the noise is lower. When the heat exchange performance WH is the same as that of the conventional air conditioner, that is, when the air flow Q is the same, the impeller rotation speed N can be reduced. As shown in FIG. 56, the relationship between the air volume Q and the power consumption Wm of the motor 3 and the noise value SPL change diagram when the air volume Q changes in FIG. Low power consumption and low noise can be achieved. Therefore, energy saving and low noise of the air conditioner can be achieved. In FIG. 56, the vertical axis represents the power consumption Wm [W], and the horizontal axis represents the air volume Q.
[M3 / min], and in FIG. 57, the vertical axis represents the noise value SP.
L [dBA] and the air volume Q [m3 / min] on the horizontal axis,
In each case, the solid line in the figure indicates the case of the related art, and the broken line indicates the case of the present invention.

Further, since the turbo fan 1 of the present invention has higher pressure, higher air volume and lower noise than the conventional turbo fan,
At the same heat exchange performance and the same noise as the air conditioner 100 equipped with the conventional turbo fan, the outer diameter φD2 of the turbo fan impeller 1a can be reduced, so that the interval S between the heat exchanger 103 and the impeller 1a can be increased. Therefore, the flow velocity of the blowout flow F2 of the impeller 1a toward the heat exchanger 103 becomes lower, so that the noise frequency characteristic is plotted with the noise SPL [dBA] on the vertical axis and the frequency f [kHz] on the horizontal axis in FIG. As shown in the figure, the noise around 2.5 to 5 [KHz] generated when the conventional turbo fan of FIG. 85 is mounted, like the frequency characteristic value when the turbo fan of the present invention is mounted indicated by the lower solid line. Is reduced in noise, and the sense of hearing is improved.

Since the turbo fan 1 has a high pressure and a high air volume, the wind speed passing through the heat exchanger 103 can be increased, so that the heat exchange performance can be improved. Therefore, the height of the heat exchanger 103 can be reduced at the same heat exchange performance as the conventional one. As a result, the height of the air conditioner main body 101 can be reduced, so that the air conditioner main body 101 can be made compact and the weight can be reduced.

[0111]

As described above, according to the first aspect of the present invention, there is provided a main plate extending from the center of rotation to the outer peripheral side of the rotation, a shroud opposed to the main plate and forming a gas flow path, In a turbo fan having a blade in which an outlet angle βb2 of a backward facing blade facing a plurality of rotation directions disposed between the main plate and the shroud and having an outlet angle βb2 of 90 ° or less, an impeller rotation direction side of the blade An airfoil whose surface has a smooth convex shape in the rotation direction near the center from the inner periphery of the impeller, and a concave shape smoothly continuous in the rotation direction from near the center of the impeller to the outer periphery of the impeller. Because of the shape of the blade cross section, even if the suction flow of the blade on the inner peripheral side of the impeller fluctuates, it is difficult for the blade to separate and the noise is reduced, and the pressure on the outer peripheral side of the impeller can be increased.
In addition, the chord length is minimally reduced compared to conventional turbofans, and the blade exit angle can be increased.
The pressure rise at the blade outlet is high, and there is an effect that a large air volume can be obtained.

According to the second aspect of the present invention, since the surface of the blade opposite to the impeller rotation direction has a smooth concave shape in the rotation direction from near the center of the blade to the outer periphery of the impeller. In addition to the effects of the invention, since the blades are not bent sharply in the rotational direction as in the conventional turbofan, the blades are smoothly deflected to a concave shape and adhere to the blade surface, so that the pressure rise does not easily occur. On the other hand, even if air path resistance is added to the suction side or the outlet side of the turbofan, there is an effect that a lower noise and a larger air volume can be obtained as compared with the conventional turbofan.

According to the third aspect of the present invention, the surface of the impeller in the direction opposite to the impeller rotation direction has a concave shape that is entirely smooth in the rotation direction from the inner periphery of the impeller to the outer periphery of the impeller. In addition to the effects of the invention described above, the difference in flow velocity between the surface in the rotation direction of the blade and the surface on the opposite side can be increased, so that the pressure rise can be further increased, and as a result, a turbofan with high air blowing efficiency can be obtained.

According to the fourth aspect of the present invention, a main plate extending from the center of rotation to the outer peripheral side of the rotation, a shroud arranged opposite to the main plate to form a gas flow path, and a shroud provided between the main plate and the shroud. In a turbofan having a blade in which the outlet angle βb2 of the rearwardly facing blade facing in the opposite direction to the plurality of rotation directions is 90 ° or less, the warp line of the blade is arranged from the inner peripheral side of the impeller of the blade. The vicinity of the center is a circular arc having a convex shape with respect to the rotation direction, and from the vicinity of the center of the blade to the outer peripheral side of the impeller is formed with a circular arc having a concave shape with respect to the rotation direction. Even if the suction flow of the impeller fluctuates, it is difficult for the impeller to separate at the tip on the inner peripheral side of the impeller, and the outer peripheral side of the impeller has a smooth concave shape with respect to the rotation direction. The noise can be reduced because it is difficult to peel even at the part. Further, since the blade exit angle can be increased with a small decrease in the chord length, the pressure rise at the blade exit is high, the blowing efficiency is high, and a low-noise turbofan can be obtained. Furthermore, since the sled lines of the blades are continuous two circular arcs having the same radius, they are simpler than those having a plurality of circular arcs having different radii.

According to the fifth aspect of the present invention, there is provided a reverse warp starting point Ag which is an inflection point at which the warp line of the blade changes from a convex shape to a concave shape in the impeller rotation direction. Since the starting point Ag moves toward the inner periphery of the impeller as it moves from the main plate side to the shroud side in the height direction of the impeller, the wind speed near the shroud of the blade increases, the blowout wind speed is uniformed, and an obstacle is present near the impeller. Even if it is present, there is a time difference in the height direction of the impeller with respect to the discharge of the blowing flow, so that the noise is reduced. In addition, even if the suction flow of the impeller fluctuates, it is difficult for the impeller to be peeled off at the inner peripheral end of the impeller, and since the outer peripheral side of the impeller is smooth or concave with respect to the rotation direction, the impeller also has an outer peripheral portion. Noise can be reduced because it is difficult to peel. In addition, since the blade exit angle can be increased with a small decrease in chord length, a turbofan with a high pressure rise at the blade exit, high air-blowing efficiency, low noise, and improved blow-out air speed distribution can be obtained.

According to the sixth aspect of the present invention, the tip of the impeller on the outer peripheral side of the impeller moves toward the rotation direction as it moves from the main plate side in the height direction of the impeller to the shroud side. In addition, it is possible to obtain a turbo fan in which the blow-out wind speed distribution is further uniformed and the blow-out timing is changed to further reduce noise.

According to the seventh aspect of the present invention, a main plate extending from the center of rotation to the outer periphery of the rotation, a shroud opposed to the main plate to form a gas flow path, and a main plate and a shroud provided between the main plate and the shroud. In a turbofan having a blade in which an outlet angle βb2 of a rearwardly facing blade facing in a direction opposite to a plurality of rotation directions is 90 ° or less, the entire surface of the blade has a concave shape with respect to the rotation direction. Since it has an airfoil shape, in the flow velocity distribution between the blades at the outer peripheral tip of the blades, the flow on the rotation direction side surface with a high flow velocity can be further increased, and a large speed difference from the rotation direction opposite surface can be obtained. The pressure rise can be increased. Therefore, since the air pressure is high and the air volume is high, there is an effect that the air blowing efficiency is high and a low noise blower can be obtained.

According to the eighth aspect of the present invention, a main plate extending from the center of rotation to the outer periphery of the rotation, a shroud opposed to the main plate to form a gas flow path, and a main plate and a shroud disposed between the main plate and the shroud. In a turbofan having a blade in which an outlet angle βb2 of a rearwardly facing blade facing in a direction opposite to a plurality of rotation directions is 90 ° or less, a blade having a wing shape having a hollow structure, and the blade being a main plate. The size of the radius R of the R shape of the mounting portion to be mounted is the maximum thickness tmax of the blade.
As described above, since the force due to the torque applied to the impeller at the time of starting the motor does not concentrate on the mounting portion, the strength of the impeller is improved.

According to the ninth aspect of the present invention, the motor, the impeller driven to rotate by the motor, the suction grill disposed on the air suction side of the impeller, and the air blow side of the impeller. In the blower including the blow-out grill to be arranged, since the impeller is the turbo fan according to any one of claims 1 to 8, the turbo fan with high total pressure, high air volume, and low noise is mounted. Since the circulation of the air in the room can be further promoted, there is an effect that the temperature unevenness in the height direction of the room can be reduced in a short time with low noise.

According to the tenth aspect of the present invention, there is provided an air blower which draws in and blows indoor air and a heat exchanger which is disposed on the blow side of the blower and heats or cools air passing through the blower. In the harmony machine, since the blower is the turbofan according to any one of claims 1 to 8, a high total pressure, a high airflow, and a low-noise turbofan are mounted. Therefore, the power consumption of the motor can be reduced, energy can be saved, and noise can be reduced. Or, at the same heat exchanger performance and the same noise, the turbo fan impeller outer diameter can be reduced,
Since the distance to the heat exchanger can be increased, the peculiar sound generated from the heat exchanger can be controlled and the audibility can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a turbo fan according to Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of the impeller of the turbofan according to Embodiment 1 of the present invention.

FIG. 3 relates to the first embodiment of the present invention,
It is a horizontal sectional view in Y.

FIG. 4 is an enlarged cross-sectional view of one blade of FIG. 3 according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a blowing characteristic (φ) according to the first embodiment of the present invention.
FIG. 4 is a diagram illustrating a noise characteristic (φ-SPL) and a noise characteristic (φ-SPL).

FIG. 6 is a perspective view of a turbo fan according to Embodiment 2 of the present invention.

FIG. 7 is a longitudinal sectional view of an impeller of a turbofan according to Embodiment 2 of the present invention.

FIG. 8 relates to the second embodiment of the present invention,
It is a horizontal sectional view in Y.

FIG. 9 is an enlarged cross-sectional view of one of the blades of FIG. 8 according to the second embodiment of the present invention.

FIG. 10 is a diagram showing a blowing characteristic (φ) according to Embodiment 2 of the present invention.
FIG. 4 is a diagram illustrating a noise characteristic (φ-SPL) and a noise characteristic (φ-SPL).

FIG. 11 is a longitudinal sectional view of a turbofan according to Embodiment 3 of the present invention.

FIG. 12 relates to the third embodiment of the present invention, and corresponds to Y in FIG.
It is a horizontal sectional view in -Y.

FIG. 13 is an enlarged cross-sectional view of one blade of FIG. 12 according to the third embodiment of the present invention.

FIG. 14 is a view showing a blowing characteristic (φ) according to Embodiment 3 of the present invention.
FIG. 4 is a diagram illustrating a noise characteristic (φ-SPL) and a noise characteristic (φ-SPL).

FIG. 15 relates to Embodiment 3 of the present invention and relates to an air volume Q [m ³ /
FIG. 6 is a change diagram of the noise value SPL [dBA] at the time of a change in [min].

FIG. 16 is a perspective view of a turbo fan according to Embodiment 4 of the present invention.

FIG. 17 is a longitudinal sectional view of a turbofan impeller according to Embodiment 4 of the present invention.

FIG. 18 relates to Embodiment 4 of the present invention and relates to Y in FIG.
It is a horizontal sectional view in -Y.

FIG. 19 is an enlarged cross-sectional view of one blade of FIG. 18 according to the fourth embodiment of the present invention.

FIG. 20 is a flow velocity distribution diagram between the blade at the tip on the outer peripheral side of the blade 2 and the next blade 2 ′ according to Embodiment 4 of the present invention.

FIG. 21 is a diagram showing a ventilation characteristic (ψ) according to Embodiment 4 of the present invention.
FIG. 3 is a diagram showing an s-φ characteristic) and a noise characteristic (φ-SPL).

FIG. 22 is a perspective view of a turbo fan according to Embodiment 5 of the present invention.

FIG. 23 is a horizontal sectional view of FIG. 22 according to the fifth embodiment of the present invention.

FIG. 24 is an enlarged cross-sectional view of one blade of FIG. 23 according to Embodiment 5 of the present invention.

FIG. 25 is a flow velocity distribution diagram between the blade 2 and the next blade 2 ′ at the tip on the outer peripheral side of the blade according to the fifth embodiment of the present invention.

FIG. 26 is a diagram showing a ventilation characteristic (ψs-φ characteristic) and a noise characteristic (φ-SPL) according to the fifth embodiment of the present invention.

FIG. 27 is a horizontal sectional view of a turbofan according to Embodiment 6 of the present invention.

FIG. 28 relates to the sixth embodiment of the present invention, and relates to K in FIG.
It is sectional drawing in the vicinity of main plate 1b in -K.

FIG. 29 is a cross-sectional view of a mounting portion between blade 2 and main plate 1b according to Embodiment 6 of the present invention.

FIG. 30 is a cross-sectional view of a mounting portion of blade 2 and main plate 1b according to Embodiment 6 of the present invention when the material of the turbofan is a sheet metal.

FIG. 31 is a cross-sectional view of a mounting portion of blade 2 and main plate 1b according to Embodiment 6 of the present invention, in a case where the material of the turbofan is a sheet metal.

FIG. 32 is a perspective view of a turbo fan according to Embodiment 7 of the present invention.

FIG. 33 is a longitudinal sectional view of FIG. 32 according to the seventh embodiment of the present invention.

FIG. 34 shows Z1 in FIG. 33 according to the seventh embodiment of the present invention.
It is a horizontal sectional view in -Z1.

FIG. 35 relates to the seventh embodiment of the present invention, and shows Z in FIG.
It is a sectional enlarged view of one blade in 3-Z3.

FIG. 36 relates to the seventh embodiment of the present invention, and shows Z in FIG.
It is a sectional enlarged view of one blade in 2-Z2.

FIG. 37 relates to the seventh embodiment of the present invention, and shows Z in FIG.
FIG. 2 is an enlarged cross-sectional view of the blade in 1-Z1.

FIG. 38 is a distribution diagram of blown air velocity at a blower outlet in a height direction of an impeller of a turbofan according to Embodiment 7 of the present invention.

FIG. 39 is a change diagram of a noise value when an air volume changes when an obstacle is arranged near the impeller of the turbo fan according to the seventh embodiment of the present invention.

FIG. 40 is a perspective view of a turbo fan according to Embodiment 8 of the present invention.

FIG. 41 is a longitudinal sectional view of FIG. 40 according to the eighth embodiment of the present invention.

FIG. 42 shows Z1 of FIG. 41 according to the eighth embodiment of the present invention.
It is a horizontal sectional view in -Z1.

FIG. 43 relates to Embodiment 8 of the present invention;
FIG. 3 is an enlarged cross-sectional view of the blade in 3-Z3.

FIG. 44 relates to the eighth embodiment of the present invention, and shows Z in FIG.
FIG. 2 is an enlarged cross-sectional view of the blade in 2-Z2.

FIG. 45 relates to Embodiment 8 of the present invention;
FIG. 2 is an enlarged cross-sectional view of the blade in 1-Z1.

FIG. 46 is a distribution diagram of blowing air velocity of a turbo fan according to Embodiment 8 of the present invention.

FIG. 47 is a frequency characteristic diagram of the turbo fan according to the eighth embodiment of the present invention at the same air volume.

FIG. 48 is a schematic installation diagram of a blower according to Embodiment 9 of the present invention.

FIG. 49 is a longitudinal sectional view of a blower according to Embodiment 9 of the present invention.

FIG. 50 is a cross-sectional view taken along the line Y- in FIG. 49 according to the ninth embodiment of the present invention.
It is a horizontal sectional view in Y.

FIG. 51 is a diagram illustrating a change in a noise value when the air volume changes according to the ninth embodiment of the present invention.

FIG. 52 is a diagram illustrating a temperature difference between the temperature near the room floor and the temperature near the room ceiling with respect to the time after the start of operation according to the ninth embodiment of the present invention.

FIG. 53 is an external view of an air conditioner according to Embodiment 10 of the present invention.

FIG. 54 is a longitudinal sectional view of an air conditioner according to Embodiment 10 of the present invention.

FIG. 55 is a horizontal sectional view of an air conditioner according to Embodiment 10 of the present invention.

FIG. 56 is a relationship diagram between the air volume Q and the power consumption Wm of the motor according to the tenth embodiment of the present invention.

FIG. 57 is a diagram showing a relationship between air volume Q and noise value SPL according to the tenth embodiment of the present invention.

FIG. 58 is a frequency characteristic diagram according to Embodiment 10 of the present invention.

FIG. 59 is an explanatory diagram of a turbofan in a conventional document.

FIG. 60 is an explanatory diagram of a multi-blade fan in a conventional document.

FIG. 61 is an explanatory diagram of a radial fan in a conventional document.

FIG. 62 is a horizontal sectional view of a first conventional turbofan.

FIG. 63 is a longitudinal sectional view of the turbo fan of FIG. 62.

FIG. 64 is an enlarged view of the vicinity of a tip end on the inner peripheral side of the impeller of the blade of FIG. 62.

FIG. 65 is a horizontal sectional view of a second conventional turbofan.

FIG. 66 is a longitudinal sectional view of the turbofan of FIG. 65.

FIG. 67 is an enlarged view of one blade of FIG. 65;

FIG. 68 is a diagram showing an example of a conventional two-blade blade-shaped turbofan in which a warp line has two circular arc shapes having different radii.

FIG. 69 is a diagram showing an example of a conventional multi-blade blade-shaped turbofan in which the sled lines are three or more arcs having different radii.

FIG. 70 is a schematic view of the blade of the second conventional turbofan when the outlet angle βb2 is enlarged while keeping the position of the tip on the inner circumferential side of the blade the same.

FIG. 71 is a view showing a flow velocity distribution between the blade 2 and the next blade 2 ′ in the second conventional turbofan.

FIG. 72 is a view showing a distribution of blown air velocity in a height direction of an outlet 1e of an impeller in a second conventional turbofan.

FIG. 73 is a perspective view of a third conventional turbofan.

74 is a horizontal sectional view of the turbo fan of FIG. 73.

FIG. 75 is a perspective view of a turbofan having a hollow blade 2 in a second conventional turbofan.

FIG. 76 is a sectional view of a mounting portion between a blade and a main plate of a conventional turbofan.

FIG. 77 is a schematic view of attachment of blades and a main plate in a conventional sheet metal fan.

FIG. 78 is a schematic view showing the state of attachment after caulking in FIG. 77.

FIG. 79 is a schematic view of installation of a conventional ceiling-mounted air conditioner.

FIG. 80 is a longitudinal sectional view of the ceiling-mounted air conditioner of FIG. 79.

FIG. 81 is a horizontal sectional view of FIG. 80;

FIG. 82 is a velocity triangular diagram of a fan blowing flow in a forward blade (multi-blade fan).

FIG. 83 is a velocity triangular diagram of a fan blowing flow in a radial blade (radial fan).

FIG. 84 is a diagram showing a state in which the angle of attack of the heat emitted from the heat exchanger with respect to the fins is large.

FIG. 85 is a frequency characteristic diagram when a conventional turbo fan is mounted.

[Explanation of symbols]

1 Turbo fan, 1a Turbo fan impeller, 1b
Main plate, 1c hub, 1d shroud, 1e impeller outlet, 2 blades, blade next to 2 'blade 2, 2a inner edge of blade, 2b outer edge of blade, 2c sled wire, 2d blade mounting hole, 2e blade mounting claw, 2P blade rotation direction surface, 2S blade rotation direction opposite surface,
3 motor, 3a motor rotation axis, 4 bell mouth,
100 air conditioner, 101 air conditioner body, 101a
Air conditioner main body side wall, 101b Air conditioner main body top plate, 102 decorative panel, 102a suction grill, 10
2b outlet, 103 heat exchanger, 103a fin,
103b Fin tip, 104 Drain pan, 105
Filter, 106 electrical box, 107 room, 108
Under the ceiling, 109 wind direction vane, 110 air outlet, 11
1 wind direction board, 112 ceiling, 200 blower, 201
Blower body, 201a Blower body side wall, 201b
Blower main panel, 202 suction grille, 203 outlet, A impeller rotation direction, B2 fan outlet height, C
2 Absolute outflow velocity, D2 impeller outer diameter, E Where the angle of attack θ of the blown flow with respect to the fin of the heat exchanger is large, F1
Suction flow, F2 fan discharge flow, G1 separation vortex at heat exchanger fin tip, G2 separation vortex at blade surface,
L0 chord, L2 chord length, Ag reverse warp start point, Mo
a straight line passing through the inner peripheral end 2a, perpendicular to a straight line O-2a passing through the impeller rotation axis center O and passing through the inner peripheral end 2a, M
ob A straight line passing through the center O of the impeller rotation axis and passing through the outer peripheral end 2b and perpendicular to a straight line O-2b passing through the outer peripheral tip 2b.
Mc1 The tangent at the inner peripheral tip 2a of the sled 2c of the blade, the Mc2 the tangent at the outer tip 2b of the sled 2c of the blade, M2P The tangent at the outer tip 2b of the surface 2P in the rotation direction of the blade 2, M2S rotation The tangent at the outer peripheral end 2b of the blade 2 on the surface 2S on the opposite side to the direction, the distance between the impeller of the turbofan and the heat exchanger, the thickness of the blade, △
Ta Temperature difference between the vicinity of the room floor and the room ceiling, U2 peripheral speed, section of Y blade 2, section of Z1 blade near main plate,
Cross section of the Z2 blade near the center in the height direction of the impeller, Z3 cross section of the blade near the shroud, α Angle of attack of the heat exchanger fins and blowout flow, βb1 blade entrance angle, βb2 blade exit angle, βP2 rotation direction side Surface exit angle, βS2 Rotation direction reverse surface exit angle, O impeller rotation axis center, θ Outflow angle.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Matsushita 2-6-1 Otemachi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Engineering Co., Ltd. (72) Eiji Fukushima 2-3-2 Marunouchi, Chiyoda-ku, Tokyo No. 3 Mitsubishi Electric Co., Ltd. (72) Inventor Atsushi Edayoshi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 3H033 AA02 AA18 BB02 BB06 CC01 DD03 DD19 DD27 EE06 EE08 3H035 CC01 CC06 3L049 BD01

Claims (10)

[Claims] 1. A main plate extending from a rotation center side to a rotation outer peripheral side, a shroud arranged to face the main plate to form a gas flow path, and a plurality of rotation directions arranged between the main plate and the shroud in opposite directions. In a turbofan having a blade in which the outlet angle βb2 of the rearwardly facing blade is 90 ° or less, the surface of the blade in the direction of rotation of the impeller is smooth from the inner peripheral side of the impeller to the rotation direction. A turbofan having an airfoil-shaped blade cross section that is convex and continuous from the vicinity of the center of the impeller to the outer periphery of the impeller in a smooth concave shape in the rotation direction. 2. The impeller according to claim 1, wherein the surface of the impeller in the direction opposite to the rotational direction has a smooth concave shape in the rotational direction from near the center of the impeller to the outer peripheral side of the impeller.
The turbofan described. 3. The surface of the impeller in the direction opposite to the impeller rotation direction has a concave shape that is entirely smooth in the rotation direction from the inner circumference of the impeller to the outer circumference of the impeller.
The turbofan described. 4. A main plate extending from a rotation center side to a rotation outer peripheral side, a shroud arranged to face the main plate to form a gas flow path, and a plurality of rotation directions arranged between the main plate and the shroud in opposite directions. In a turbofan having a blade in which the outlet angle βb2 of the backward facing blade is 90 ° or less, the warp line of the blade has a convex shape with respect to the rotation direction near the center from the inner periphery of the impeller of the blade. In the arc of
A turbo fan, comprising a circular arc that is concave from the vicinity of the center of the blade to the outer periphery of the impeller with respect to the rotation direction, and the circular arc is formed by two continuous circular arcs having the same radius. 5. A reverse warp starting point A, which is an inflection point at which the warp line of the blade changes from a convex shape to a concave shape in the rotation direction of the impeller.
5. The turbofan according to claim 4, wherein the reverse-warp start point Ag shifts from the main plate side to the shroud side in the impeller height direction toward the inner periphery of the impeller. 6. The turbofan according to claim 5, wherein the tip of the impeller on the outer peripheral side of the impeller moves toward the rotational direction from the main plate side in the height direction of the impeller toward the shroud side. 7. A main plate extending from the rotation center side to the rotation outer peripheral side, a shroud arranged to face the main plate to form a gas flow path, and a plurality of rotation directions arranged between the main plate and the shroud in opposite directions. In a turbofan having a blade whose outlet angle βb2 of the backward facing blade is 90 ° or less, the entire surface of the blade has an airfoil shape that is concave with respect to the rotation direction. Turbo fan. 8. A main plate extending from the rotation center side to the rotation outer peripheral side, a shroud arranged to face the main plate to form a gas flow path, and a plurality of rotation directions arranged between the main plate and the shroud in opposite directions. In a turbofan having a blade whose outlet angle βb2 of the backward facing blade is 90 ° or less, an airfoil-shaped blade having a hollow structure, and an R-shaped mounting portion where the blade is mounted on the main plate. Radius R
Characterized in that the size of the turbo fan is equal to or greater than the maximum blade thickness tmax. 9. A motor, an impeller rotatably driven by the motor, a suction grill disposed on an air suction side of the impeller, and a blow grill disposed on an air outlet side of the impeller. A blower, wherein the impeller is the turbofan according to any one of claims 1 to 8. 10. An air conditioner comprising: a blower that sucks and blows indoor air and blows out the air; and a heat exchanger that is disposed on a blowout side of the blower and heats or cools air passing through the blower. An air conditioner comprising the turbofan according to any one of claims 1 to 8.