WO2008072558A1

WO2008072558A1 - Centrifugal impeller and centrifugal blower using it

Info

Publication number: WO2008072558A1
Application number: PCT/JP2007/073639
Authority: WO
Inventors: Seiji Shirahama; Hitoshi Yoshikawa
Original assignee: Panasonic Corporation
Priority date: 2006-12-14
Filing date: 2007-12-07
Publication date: 2008-06-19

Abstract

A centrifugal impeller (14) and a centrifugal blower (1) include a main plate (15), blades (18), an annular plate (20), and a cylindrical wall (22). The blades (18) are annularly disposed on the outer peripheral side of the front surface (17) of the main plate (15). The annular plate (20) is attached to the tip ends (19) of the blades (18). The cylindrical wall (22) is so provided on the rear surface (21) of the main plate (15) as to be coaxial with the main plate (15). With this constitution, the centrifugal impeller (14) and the centrifugal blower (1) with improved air-blowing efficiency and reduced noise can be obtained.

Description

Specification

Centrifugal impeller and centrifugal fan using it

Technical field

TECHNICAL FIELD [0001] The present invention relates to a centrifugal impeller used for ventilation and ventilation equipment and air conditioning equipment and the like, and a centrifugal blower using the same.

Background art

[0002] In recent years, in ventilation and ventilation equipment and air conditioning equipment used in residential and non-residential spaces, downsizing of the equipment has been required along with the reduction of installation space. On the other hand, there is a demand for a centrifugal impeller and a centrifugal fan with improved blowing efficiency and reduced noise.

Hereinafter, a conventional centrifugal impeller and a centrifugal fan will be described with reference to FIG. As shown in FIG. 14, the centrifugal fan 101 has a casing 107, a centrifugal impeller 112 having a multi-blade impeller shape, and an electric motor 113. The casing 107 has a suction plate 103, a back plate 104 facing the suction plate 103, and a side wall 106. The casing 107 is configured by sandwiching the suction plate 103, the back plate 104 and the force side wall 106. The suction plate 103 has a bell mouth-like suction port 102. Side wall 106 has a spiral shape and has an outlet 105. The centrifugal impeller 112 is provided inside the casing 107 and has an annular side plate 108, a main plate 110, and a plurality of blades 111. The main plate 110 has a throttling portion 109. The throttling portion 109 has a cone shape which is convex toward the side plate 108 side. A centrifugal impeller 112 is configured by sandwiching the side plate 108, the main plate 110, and the force blade 111. In addition, a centrifugal impeller 112 is connected to the rotating shaft 114 of the motor 113. The motor 113 is attached to the back plate 104. Such a centrifugal fan 101 is disclosed, for example, in Japanese Patent No. 3629690 (referred to as Patent Document 1).

The centrifugal fan 101 has the above-described configuration, and the centrifugal impeller 112 is rotated by applying a driving force from the electric motor 113 to the rotating shaft 114. As the centrifugal impeller 112 rotates, suction air 115 passes through the suction port 102, flows into the blade 111, and is pressurized. Further, the suction air 115 flows out of the blade 111, gradually converts from dynamic pressure to static pressure when passing through the casing 107, and is discharged from the discharge port 105 to the outside. Ru. At this time, the pressure of the flow 116 flowing out of the blade 111 and passing through the casing 107 is high. For this reason, a partial force of the flow 116 flowing out of the blade 111 flows between the main plate 110 and the back plate 104 to generate a reverse flow 117. Ventilation holes 118 are provided in the main plate 110 in order to prevent the backflow 117 from stagnating in a stagnant state and lowering the air blowing performance of the centrifugal air blower 101. The provision of the vent holes 118 forms a circulating flow 119 which flows back into the reverse flow 117 force S blade 111. As a result, the decrease in blowing efficiency is suppressed. Furthermore, the vent holes 118 prevent the suction air 115 from colliding with the throttling portion 109 and flowing into the blade 111. Further, the vent holes 118 guide the suction air 115 and the circulating flow 11 9 to the motor 113 to promote cooling of the motor 113.

Another conventional centrifugal fan 101 will be described with reference to FIG. As shown in FIG. 15, in the centrifugal fan 101, a portion of the back plate 104 of the casing 107 outside the centrifugal impeller 112 bulges in the rotation axis direction. Furthermore, the degree of expansion gradually increases toward the discharge port 105 in the rotational direction. Such a centrifugal fan 101 is disclosed, for example, in Japanese Patent No. 2690005 (referred to as Patent Document 2).

Centrifugal blower 101 has the configuration as described above, and the flow path from which centrifugal impeller 112 flows out can have a wide flow path. Further, as the flow path is gradually expanded toward the discharge port 105, the efficiency of the centrifugal fan 101 is improved and the noise is reduced.

However, in the conventional centrifugal impeller 112 and the centrifugal fan 101 disclosed in Patent Document 1, a part of the flow 116 flowing out of the blade 111 flows back between the main plate 110 and the back plate 104. . This forms a circulating flow 119. At this time, due to the collision of the flow 116 flowing out from the vicinity of the main plate 110 and the reverse flow 117, the blade 111 near the main plate 110 can not perform effective work. For this reason, the blowing efficiency of the centrifugal blower 101 is reduced. Furthermore, due to the collision between the flow 116 and the reverse flow 117, the circulating flow 119 re-inflows into the blade 111 in a disordered state. For this reason, the blowing efficiency of the centrifugal blower 101 is reduced.

Further, the collision between the flow 116 flowing out of the blade 111 near the main plate 110 and the reverse flow 117 generates turbulent noise.

[0009] In addition, in order to miniaturize the centrifugal fan 112, a part of the motor 113 is a cone-shaped throttle. It is attempted to be placed in section 109. However, the size of the centrifugal fan 101 is difficult to reduce because the height of the throttling portion 109 is limited in relation to the size of the motor 113 and the centrifugal impeller 112.

Further, the conventional centrifugal fan 101 disclosed in Patent Document 2 includes a back plate 104 having a complicated shape in which a part of the casing 107 has a spiral shape. Due to this, the centrifugal fan 101 has a complicated structure, which increases the cost of manufacturing.

Patent Document 1: Patent No. 3629690

Patent Document 2: Patent No. 2690005

Disclosure of the invention

[0011] The present invention improves the blowing efficiency, reduces noise, reduces the size, and simplifies the structure, thereby reducing the cost of the centrifugal impeller and the centrifugal fan. provide.

The centrifugal impeller of the present invention has a disk-shaped main plate, a plurality of blades, an annular plate and a cylindrical wall, the blades are annularly disposed on the outer peripheral side of the front side of the main plate, and the annular plate is The cylindrical wall is mounted on the back surface of the main plate concentrically with the main plate. With this configuration, a centrifugal impeller with improved blowing efficiency and reduced noise can be obtained.

Further, a centrifugal fan according to the present invention includes a motor having a centrifugal impeller and a rotary shaft fixed to the centrifugal impeller, and a casing, and the centrifugal impeller includes a disk-shaped main plate and a plurality of blades. The blade has an annular plate and a cylindrical wall, the blade is annularly disposed on the outer peripheral side of the front surface of the main plate, the annular plate is attached to the tip of the blade, and the cylindrical wall is the same as the main plate on the back surface of the main plate. A core is provided, the main plate is fixed to the rotary shaft in the casing, and the casing is provided with a suction plate having a bell mouth-like suction opening, a back plate facing the suction plate, a spiral side wall, and a discharge opening. And. With this configuration, a centrifugal fan with improved blowing efficiency and reduced noise can be obtained.

Brief description of the drawings

FIG. 1A is a side sectional view showing a centrifugal impeller and a centrifugal blower according to Embodiment 1 of the present invention.

[FIG. 1B] FIG. 1B is a front partial cross-sectional view of the centrifugal impeller and the centrifugal blower shown in FIG. 1A. Garden 2] FIG. 2 is a perspective view of the centrifugal impeller shown in FIG. 1A.

Garden 3A] FIG. 3A is a side cross sectional view showing a centrifugal fan for comparison with the centrifugal fan according to the first embodiment of the present invention.

Garden 3B] FIG. 3B is a characteristic diagram showing the characteristics of the centrifugal impeller and the centrifugal fan shown in FIG. 1A. Garden 4A] FIG. 4A is a side sectional view showing a centrifugal impeller and a centrifugal fan according to Embodiment 2 of the present invention.

[FIG. 4B] FIG. 4B is a perspective view of the centrifugal impeller shown in FIG. 4A.

[FIG. 5] FIG. 5 is a side sectional view showing a centrifugal impeller and a centrifugal blower according to Embodiment 3 of the present invention.

Garden 6A] FIG. 6A is a side sectional view showing a centrifugal impeller and a centrifugal fan according to Embodiment 4 of the present invention.

[FIG. 6B] FIG. 6B is a perspective view of the centrifugal impeller shown in FIG. 6A.

[FIG. 7] FIG. 7 is a side sectional view showing a centrifugal impeller and a centrifugal fan according to Embodiment 5 of the present invention.

[FIG. 8] FIG. 8 is a side sectional view showing a centrifugal impeller and a centrifugal fan according to Embodiment 6 of the present invention.

Garden 9] FIG. 9 is a side sectional view showing a centrifugal impeller and a centrifugal fan according to Embodiment 7 of the present invention.

Garden 10] FIG. 10 is a perspective view showing a centrifugal impeller according to Embodiment 8 of the present invention.

Garden 11] FIG. 11 is a side sectional view showing a centrifugal impeller and a centrifugal fan according to a ninth embodiment of the present invention.

Garden 12] FIG. 12 is a side sectional view showing a centrifugal impeller and a centrifugal fan according to a tenth embodiment of the present invention.

Garden 13] FIG. 13 is a side sectional view showing a centrifugal impeller and a centrifugal fan according to Embodiment 11 of the present invention.

Garden 14] FIG. 14 is a side sectional view showing a conventional centrifugal impeller and a centrifugal fan.

Garden 15] FIG. 15 is a side sectional view showing a conventional centrifugal fan according to another aspect.

Explanation of sign Bottom of centrifugal fan

Side

Duct connection opening

Suction port Suction board Back board

Side wall

Casing Discharge port Rotary shaft Motor Centrifugal impeller Main plate

a Main plate projection b Joint

Ventilation hole Front side Blade a Inner blade b Edge of blade Outer tip Tip Annular plate Back side Cylindrical wall Tip

Gap 25a center

25b outer circumference

26 Hole for motor

27 suction air

28, 28a current

29 backflow

30 circulation flow

31 perimeter edge

32 Outer cylindrical wall

33 Inner cylindrical wall

34 drain hole

35 Sound absorbing material

36 circular tubular space

37 lid

38 Small holes

39 Perforated board

40 screw boss

41 screw

42 tongue

43 Main part

44 Spiral plate

45 Back plate protrusion

46 swirling flow

BEST MODE FOR CARRYING OUT THE INVENTION

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

Embodiment 1

A centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, a centrifugal blower 1 (hereinafter referred to as a blower 1) ) Has an outer shell 5, a casing 10, a discharge port 11, a motor 13 and a centrifugal impeller 14 (hereinafter referred to as an impeller 14). The outer shell 5 has an open lower surface 2 and a duct connection opening 4 (hereinafter referred to as an opening 4) on the side surface 3. The size of the outer shell 5 is 258 mm square and the height is 198 mm. The casing 10 has a suction plate 7, a back plate 8 and a side wall 9 provided in the outer shell 5, and the casing 10 is configured by sandwiching the side wall 9 with the suction plate 7 and the back plate 8. There is. The suction plate 7 has a suction port 6 having a bell mouth shape. The inside diameter Do of the suction port 6 is 148 mm. The back plate 8 has a flat plate shape facing the suction plate 7. The side wall 9 has a spiral shape and has a height He of 107 mm. The discharge port 11 is provided in the side wall 9 and communicates with the opening 4. The motor 13 has a rotating shaft 12 provided concentrically with the suction port 6 and is fixed to the back plate 8. The size of the motor 13 is 75 mm in diameter and 80 mm in height. The impeller 14 has a multi-wing shape and is fixed to the rotation shaft 12 of the motor 13. Due to the multi-blade shape of the impeller 14, the blower 1 is small in size and has high pressure and low noise characteristics. These features are required for ventilation and ventilation equipment. A duct 50 is provided outside the opening 4. Further, the tongue portion 42 is formed at a portion including the minimum gap between the outer peripheral portion of the impeller 14 and the casing 10. The blower 1 is used, for example, as an in-ceiling recessed ventilation fan mounted on a ceiling to ventilate a bathroom or a space such as a toilet.

Further, the impeller 14 has a main plate 15, blades 18, an annular plate 20 and a cylindrical wall 22. The main plate 15 has a disk shape having an outer diameter Dm of 182 mm and a thickness of 3 mm. Ventilation holes 16 are disposed on the main plate 15 so that air can pass through the main plate 15. In addition, six ventilation holes 16 are annularly provided. Fifty blades of 18 force S are joined at the joint portion 15b on the outer peripheral side of the front side surface 17 of the main plate 15, and are arranged at equal intervals in a ring shape. Due to this, the blade 18 forms a multi-bladed impeller shape having a blade inner peripheral portion 18a and a blade outer peripheral portion 18b. The blade 18 has the same outer diameter Dbo of the outer peripheral portion 18b of the blade 18 as the outer diameter Dm of the main plate 15 of 182 mm, and the inner diameter Dbi of the blade inner peripheral portion 18a is the inner diameter Do of the suction port 6 of 148 mm It has the same dimensions and a blade height Hb of 77 mm. The annular plate 20 is attached to the outer periphery of the tip 19 of the blade 18. The outer diameter Dr of the annular plate 20 is 191. 5 mm and the height is 3 mm. The cylindrical wall 22 is the back of the main plate 15 The side plate 21 is provided concentrically with the main plate 15. The cylindrical wall 22 has an outer diameter Dwo of 182 mm having the same dimension as the blade outer diameter Dbo, and a height Hw of 27 mm which is at least 30% and at most 40% of the height Hb of the blade 18 , Thickness is 2 mm. The gap 24 between the tip 23 of the cylindrical wall 22 and the back plate 8 is 3 mm. The central portion 25a of the main plate 15 protrudes 30 mm to the suction port 6 side. The main plate 15 has a main plate projecting portion 15a that protrudes in a cone shape that inclines gently from the central portion 25a toward the outer peripheral portion 25b. The vent holes 16 have a fan-like shape substantially viewed in the axial direction. The outer diameter Dh of the ventilation holes 16 is 145 mm, which is the same size as the inner diameter Dbi of the blade. Further, the area on the outer peripheral portion 25b side from the ventilation hole 16 of the main plate 15, that is, the joint 15b is inclined radially outward from the outer peripheral edge 31 of the ventilation hole 16 to the cylindrical wall 22 side. That is, the joint portion 15b is inclined toward the cylindrical wall 22 as it goes radially outward. The front side surface 17 of the main plate 15 is the side facing the inlet 6 of the main plate 15, and the back side 21 of the main plate 15 is the side facing the back plate 8 of the main plate 15.

As described above, the impeller 14 has the cylindrical wall 22. Furthermore, the back plate 8 has a flat plate shape. For this reason, the height He = 107 mm of the side wall 9 is higher than the blade height Hb = 77 mm by the height Hw of the cylindrical wall 22. As a result, the flow path of the casing 10 is expanded, and the volume of the flow 28 is increased. Furthermore, the impeller 14 is manufactured at low cost because the back plate 8 has a flat shape. As a result, it is possible to easily obtain the impeller 14 and the blower 1 which have a low cost structure and improve the blowing efficiency.

Further, the motor 13 penetrates the motor hole 26 of the back plate 8, and a half of the motor 13 protrudes into the casing 10 and is contained inside the cylindrical wall 22. In addition, since the main plate 15 has a cone shape, the motor 13 does not come in contact with the impeller 14.

In the blower 1, a driving force is applied from the electric motor 13 to the impeller 14 through the rotation shaft 12, and the impeller 14 rotates. As a result, suction air 27 sucked into the blower 1 passes through the suction port 6, flows into the blade 18, and is pressurized. Further, when the sucked air flows out of the blade 18 and passes through the casing 10, the dynamic pressure is gradually converted to a static pressure efficiently and discharged from the discharge port 11 to the outside of the fan 1 through the duct 50. Be done.

At this time, suction air 27 is sucked from the tip 19 side and flows out from the blade 18. The stream 28 flowing out of the blade 18 runs obliquely. Although the force is high, the height Hc = 107 mm of the side wall 9 is higher than the blade height Hb = 77 mm by the height Hw of the cylindrical wall 22. Therefore, the distance between the suction port 6 and the portion outside the impeller 14 of the back plate 8 and the suction port 6 is larger than the distance between the main plate 15 and the suction port 6. This reduces the speed at which the stream 28 flowing out of the blades 18 impinges on the backplate 8. As a result, the blowing efficiency between the impeller 14 and the blower 1 is improved.

Furthermore, a cylindrical wall 22 concentric with the main plate 15 is provided on the back surface 21. As a result, the flow of the fluid flowing out of the blade 18 is suppressed to the back side 21 side. For this reason, the flow receives frictional force from the back side 21 and the flow is not disturbed. As a result, in the impeller 14 and the blower 1, the decrease in the blowing efficiency is suppressed. In addition, since the impeller 14 is rotating, the cylindrical wall 22 is also rotating. As a result, a rotational force is applied to the flow 28 flowing out of the blade 18 by the frictional force with which the cylindrical wall 22 rotates. As a result, the blowing efficiency between the impeller 14 and the blower 1 is improved.

Furthermore, the pressure of the flow out of the blade 18 through the casing 10 is high. As a result, a reverse flow 29 is generated which flows into the gap 24 between the partial force impeller 14 and the back plate 8 of the flow 28 flowing out of the blade 18. Since the cylindrical wall 22 concentric with the main plate 15 is provided on the back side 21 while the force is applied, the amount of the backflow 29 is reduced. Furthermore, the ventilation holes 16 are provided in the main plate 15, so that stagnation of the backflow 29 in a stagnant state is suppressed, and a decrease in the air blowing performance of the blower 1 is prevented.

The ventilation holes 16 prevent the suction air 27 from colliding with the main plate 15 and flowing into the blades 18. Further, the suction air 27 or the circulation flow 30 is introduced to the motor 13 to promote the cooling of the motor 13.

In addition, a partial force of the flow 28 flowing out of the blade 18 forms a reverse flow 29 of the flow 28 and passes through the vent holes 16 to form a circulating flow 30 flowing into the blade 18 again. At this time, due to the cylindrical wall 22 being provided, the backflow 29 occurs at a location away from the blade 18. For this reason, the collision of the flow 28 flowing out of the blade 18 and the reverse flow 29 in the vicinity of the main plate 15 of the blade 18 is avoided. As a result, the vicinity of the main plate 15 of the blade 18 performs effective work, and a decrease in the blowing efficiency of the blower 1 is suppressed. Also, the collision between the flow 28 and the backflow 29 Generation of turbulent noise due to That is, the blower 1 and the impeller 14 improve the blowing efficiency and reduce the noise.

In addition, a part of the force 28 of the flow 28 that has flowed out of the blade 18 flows back through the back side 21, passes through the vent holes 16, and flows into the blade 18 again. However, the inner diameter Dbi of the blade 18 and the outer diameter Dh of the ventilation hole 16 have the same dimensions. As a result, the occurrence of the disturbance of the air flow, which is likely to be generated by the outer peripheral edge 31 of the ventilation hole 16, is suppressed. Therefore, the flow flowing into the blade 18 is not disturbed, and the decrease in the blowing efficiency is suppressed. Furthermore, the generation of turbulent noise is suppressed. As a result, the blowing efficiency of the blower 1 is improved and the noise is reduced.

In addition, a part of the flow 28 flowing out of the blade 18 flows backward to the back side 21. However, the blade outer diameter Dbo and the outer diameter Dwo of the cylindrical wall 22 have the same size. This suppresses the occurrence of air flow disturbance that is likely to occur due to the step between the main plate 15 and the cylindrical wall 22. Therefore, the flow of the reverse flow 29 is not disturbed, and the decrease in the blowing efficiency is suppressed. Furthermore, the generation of turbulent noise is suppressed. As a result, the blowing efficiency of the blower 1 is improved and noise is reduced.

Further, a part of the flow 28 flowing out of the blade 18 backflows to form a circulating flow 30. However, since the main plate projecting portion 15 a protruding like a partial force cone inside the blade 18 of the main plate 15 is provided, the three-dimensional area of the ventilating hole 16 is large. This causes the circulating flow 30 to pass smoothly through the vent holes 16 and back to the blades 18 again. For this reason, the disturbance of the inflow to the blade 18 is suppressed, and the reduction of the blowing efficiency and the generation of the turbulent noise are suppressed. As a result, the blowing efficiency of the blower 1 is improved and the noise is reduced.

In addition, the joint portion 15b where the main plate 15 and the blade 18 are joined to the outer peripheral portion 25b side from the ventilating hole 16 is directed radially outward from the outer peripheral edge 31, and inclined toward the cylindrical wall 22 side. doing. That is, the joint portion 15b is inclined toward the cylindrical wall 22 as the radial outward force is applied. This causes the flow area to gradually expand while the suction air 27 passes through the blade 18, and the flow 28 rapidly expands after flowing out of the blade 18. Therefore, the occurrence of flow expansion loss is suppressed. As a result, the blowing efficiency of the blower 1 is improved.

Further, a part of the motor 13 is contained inside the cylindrical wall 22. Therefore, the height of the combination of the impeller 14 and the motor 13 can be reduced. As a result, the size of the blower 1 Is miniaturized.

Further, the height Hw of the cylindrical wall 22 is 30% or more and 40% or less of the blade height Hb. As a result, the cylindrical wall 22 has a high effect of avoiding the collision between the flow 28 and the backflow 29. As a result, the blowing efficiency between the impeller 14 and the blower 1 is improved, and the noise is reduced. Furthermore, the impeller 14 and the blower 1 can be obtained which are reduced in size.

The cylindrical wall 22 may be formed by resin molding. In the case where the cylindrical wall 22 is formed by resin molding, even if the cylindrical wall 22 has a draft degree like a draft or irregularities such as ribs for reinforcing the strength, the circulation flow 30 is inhibited. If not, the above effects can be obtained. The back plate 8 has a flat plate shape. Even though the back plate 8 has strength reinforcement or embossing for attaching other parts, hole processing, bending of the outer periphery, etc., the same effect can be obtained. Be

Next, the effects of the centrifugal impeller 14 and the centrifugal fan 1 of the present invention will be described using FIGS. 3A and 3B. FIG. 3A shows a side cross-sectional view of a centrifugal fan 201 (hereinafter referred to as fan 201) for comparison. FIG. 3B is a characteristic diagram comparing air volume-static pressure characteristics and air volume-noise characteristics of the blower 1 of the present invention and the blower 201 for comparison.

As shown in FIG. 3A, the blower 201 of the present invention is not provided with the cylindrical wall 22 in the blower 201. Therefore, the back plate 208 protrudes in the area occupied by the cylindrical wall 22. That is, the dimension of the gap 224 between the back surface 221 of the main plate 215 and the back plate 208 in the fan 201 is the same as the dimension of the gap 24 between the tip 23 and the back plate 8 in the fan 1. Other shapes, for example, the blade outer diameter Dbo of the centrifugal impeller 214, or the blade height Hb, the height He of the side wall 209 of the casing 210, and the like have the same dimensions as the blower 1 of the present invention.

That is, the blower 201 has an outer shell 205, a casing 210, an outlet 211, a motor 213, and a centrifugal impeller 214 (hereinafter referred to as an impeller 214). The outer shell 205 is open at the lower surface 202 and has an opening 204 for duct connection on the side surface 203. The casing 210 has a suction plate 207, a back plate 208 and a side wall 209. The suction plate 207 has a suction port 206. The inside diameter Do of the suction port 206 is 148 mm. The side wall 209 has a height He of 107 mm. The discharge port 211 is provided on the side wall 209 and is in communication with the duct connection opening 204. The motor 213 is And a rotary shaft 212 provided concentrically with the suction port 206, and fixed through the motor hole 226 provided on the back plate 208. The impeller 214 has a multi-wing shape and is fixed to the rotation shaft 212 of the motor 213.

Furthermore, the impeller 214 has a main plate 215, a blade 218 and an annular plate 220. The main plate 215 has an outer diameter Dm of 182 mm and has a disk-like shape. The vent holes 216 are annularly arranged on the main plate 215. It is joined to the outer peripheral side of the front side surface 217 of the main plate 215 with the blade 218 force S, and is arranged at equal intervals in a ring shape. By this, the blades 218 form a multi-bladed impeller shape. Further, the blade 218 has the blade outer diameter Dbo the same size as the outer diameter Dm of the main plate 215, the blade inner diameter Dbi the same size as the inner diameter Do of the suction port 206, and the blade height Hb. An annular plate 220 is attached to the outer periphery of the tip 219 of the blade 218. The outer diameter Dr of the annular plate 220 is 191. 5 mm and the height is 3 mm. The main plate 215 has a cone-like shape which gently inclines from the central portion 225a to the outer peripheral portion 225b. The vent holes 216 have a fan-like shape substantially viewed in the axial direction. The vent holes 216 have an outer diameter Dh of 145 mm, which is the same size as the blade inner diameter Dbi. Furthermore, the area on the outer peripheral portion 225 b side from the ventilation holes 216 of the main plate 215 is inclined radially outward. That is, the area on the outer plate 225 b side from the ventilation holes 216 of the main plate 215 inclines in accordance with the radial outward force.

In FIG. 3B, the solid line 51 shows the air volume-static pressure characteristics of the blower 1 of the present invention, and the solid line 52 shows the air volume noise characteristics of the blower 1. Further, the broken line 53 indicates the air volume-static pressure characteristics of the blower 201 for comparison, and the broken line 54 indicates the air volume-noise characteristics of the blower 201. As shown in FIG. 3B, the blower 1 tends to have a low static pressure noise at the same air volume as compared with the blower 201 for comparison without the cylindrical wall 22. That is, a part of the flow 28 which has flowed out of the blade 18 forms a backflow 29 and forms a circulating flow 30 which again flows into the blade 18 through the vent holes 16. At this time, due to the provision of the cylindrical wall 22, the backflow 29 occurs at a location away from the blade 18. For this reason, in the vicinity of the main plate 15 of the blade 18, the force S is avoided that the flow 28 flowing out of the blade 18 and the reverse flow 29 collide with each other. As a result, the work near the main plate 15 of the blade 18 is effectively performed, and the decrease in the blowing efficiency is suppressed. Furthermore, due to the collision between the flow 28 and the reverse The generation of turbulent noise is suppressed, the blowing efficiency between the fan 1 and the impeller 14 is improved, and the noise is reduced. FIG. 3B is considered to represent this.

Second Embodiment

FIGS. 4A and 4B show a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 2 of the present invention. The same components as in the first embodiment will be assigned the same reference numerals and detailed explanations thereof will be omitted. In a centrifugal fan 1 according to a second embodiment of the present invention, as shown in FIGS. 4A and 4B, a cylindrical wall 22 provided on the back side 21 is an outer cylindrical wall 32 (hereinafter referred to as a wall 32). It has a double tubular shape formed by the inner cylindrical wall 33 (hereinafter referred to as the wall 33). The wall 32 constitutes the outer periphery of the cylindrical wall 22 and has an outer diameter Dwo of 182 mm. The wall 33 constitutes the inner peripheral portion of the cylindrical wall 22 and has an inner diameter Dwi of 145 mm having the same dimension as the outer diameter Dh of the ventilating hole 16 and a thickness of 2 mm. The tip 23 of the wall 33 and the tip 23 of the wall 32 lie in the same plane. Further, a circular tubular space 36 (hereinafter referred to as a space 36) is formed in the space surrounded by the wall 32 and the wall 33. A drainage hole 34 is provided between the wall 32 and the wall 33, ie, in the main plate 15 of the space 36.

Thus, by the impeller 14 having the wall 33 and the wall 32, the flow of the backflow 29 is doubly blocked by the wall 32 and the wall 33. Therefore, the amount of the circulation flow 30 is reduced, and the blowing efficiency of the blower 1 is improved.

Further, a part of the flow 28 flowing out of the blade 16 backflows to the back side 21 of the main plate 15, passes through the vent holes 16 of the main plate 15, and flows into the blade 18 again. However, the inner diameter Dwi of the wall 33 is the same size as the outer diameter Dh of the vent holes 16. As a result, the occurrence of disturbance that is likely to occur due to the step between the main plate 15 and the wall 33 is suppressed. For this reason, the disturbance of the flow flowing into the blade 18 is suppressed, and the reduction of the blowing efficiency and the generation of the turbulent noise are suppressed. As a result, the blowing efficiency of the blower 1 is improved and the noise is reduced.

In addition, the blower 1 has a drain hole 34. This prevents the moisture in the air from condensing and staying in the space 36. For this reason, the water staying in the space 36 is prevented from jumping out at the start of the rotation of the blower 1 and colliding with the side wall 9 and dropping down from the suction port 6.

In the fan 1 shown in FIG. 4B, a water draining hole 34 is provided in the main plate 15 portion. Only However, the drainage hole 34 may not necessarily be provided in the main plate 15 portion, and may be provided in the wall 32 or 33, for example. If at least one of the cylindrical wall 22 constituting the space 36 or the main plate 15 is provided with the drainage hole 34, the same action and effect are exhibited.

Third Embodiment

FIG. 5 shows a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 3 of the present invention. The same components as in Embodiments 1 and 2 will be assigned the same reference numerals and detailed explanations thereof will be omitted. In a centrifugal fan 1 according to a third embodiment of the present invention, as shown in FIG. 5, a cylindrical wall 22 is formed of a sound absorbing material 35. The sound absorbing material 35 is, for example, a hard urethane foam or the like. The sound absorbing material 35 absorbs noise in the vicinity of the impeller 14. This reduces the noise of the blower 1 and the impeller 14.

When the sound absorbing material 35 according to the third embodiment is applied to the impeller 14 according to the second embodiment, the cylindrical wall 22 having a double tubular shape has at least one wall 32, 33. Should be made of sound absorbing material 35. By this, the same action and effect can be obtained

Yes

Embodiment 4

6A and 6B show a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 4 of the present invention. The same components as in Embodiments 1 to 3 are assigned the same reference numerals and detailed explanations thereof will be omitted. As shown in FIG. 6, a centrifugal fan 1 according to a fourth embodiment of the present invention is provided with a lid 37 for closing a space 36 surrounded by the inner cylindrical wall 33 and the outer cylindrical wall 32. The lid 37 has a width corresponding to the distance between the wall 32 and the wall 33 in the radial direction of the main plate 15.

[0047] When a part of the flow 28 flowing out of the blade 18 backflows to the back surface 21 side, the provision of the lid 37 restrains the backflow with a distance in the radial direction. For this reason, the air volume of the circulation flow 30 is reduced, and the blowing efficiency of the blower 1 is improved.

[0048] It should be noted that even if the space 36 formed by being surrounded by the wall 33, the wall 32 and the lid 37 is integrally formed in a state of being packed with a packing material without forming a space, Effects and effects are obtained. Embodiment 5

FIG. 7 shows a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 5 of the present invention. The same components as in the first to fourth embodiments will be assigned the same reference numerals and detailed explanations thereof will be omitted. As shown in FIG. 7, in the centrifugal fan 1 according to Embodiment 5 of the present invention, an inner cylindrical wall 33 is formed of a perforated plate 39. The perforated plate 39 has a large number of small holes 38 with a diameter of 5 mm and has an aperture ratio of 10%, and is made of, for example, a hard fiber board.

Blower 1 is provided with a perforated plate 39 to form a perforated plate sound absorption structure. That is, the air remaining in the small holes 38 of the perforated plate 39 becomes a mass component, and the space 36 surrounded by the wall 33, the wall 32 and the lid 37 becomes a back air layer to form a vibration system. As a result, a perforated plate sound absorbing structure is formed that absorbs sound on the same principle as a Helmholtz resonator, which is a type of resonant sound absorbing structure. As a result, noise in the vicinity of the impeller 14 is silenced, and the noise of the blower 1 is reduced.

Embodiment 6

FIG. 8 shows a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 6 of the present invention. The same components as in the first to fifth embodiments will be assigned the same reference numerals and detailed explanations thereof will be omitted. In a centrifugal fan 1 according to a sixth embodiment of the present invention, as shown in FIG. 8, the inner cylindrical wall 33 is formed of a perforated plate 39. Furthermore, the space 36 surrounded by the inner cylindrical wall 33, the outer cylindrical wall 32 and the lid 37 is filled with a sound absorbing material 35. The perforated plate 39 has a large number of small holes 38 with a diameter of 5 mm and has an aperture ratio of 10%, and is made of, for example, a hard fiber board. The sound absorbing material 35 is, for example, glass wool.

With this configuration, as in the case of the blower 1 according to the fifth embodiment, a perforated plate sound absorbing structure is formed, and muffling by the perforated plate sound absorbing structure is performed. Furthermore, the sound absorbing material 35 absorbs sound. As a result, the noise in the vicinity of the impeller 14 is further reduced, and the noise of the blower 1 is reduced.

Embodiment 7

FIG. 9 shows a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 7 of the present invention. The same components as in the first to sixth embodiments are given the same reference numerals, and the detailed description is omitted. Do. As shown in FIG. 9, the centrifugal blower 1 according to Embodiment 7 of the present invention has a mortar shape in which the outer diameter Dwo of the cylindrical wall 22 gradually expands toward the tip 23. The maximum inside diameter of the cylindrical wall 22 is 200 mm.

[0054] By having fan 1 configured as shown in FIG. 9, suction air 27 is drawn from the tip 19 side, and the flow out from the blade 18 flows along the front side 17, so that the flow After the 28 has flowed out of the blade 18, it also flows out diagonally. As the outer diameter D wo of the cylindrical wall 22 gradually expands toward the tip 23, a flow 28 a which flows obliquely from the blade 18 along the cylindrical wall 22 is formed. Therefore, separation of the flow 28 a from the cylindrical wall 22 at the outer periphery of the main plate 15 is suppressed, and a decrease in the air blowing efficiency is suppressed. As a result, the blowing efficiency between the fan 1 and the impeller 14 is improved.

Embodiment 8

FIG. 10 shows a centrifugal impeller 14 according to Embodiment 8 of the present invention. The same components as those in Embodiments 1 to 7 are assigned the same reference numerals and detailed explanations thereof will be omitted. In the impeller 14 according to the eighth embodiment of the present invention, as shown in FIG. 10, a large number of screw bosses 40 are provided in the space 36 in the circumferential direction. By attaching the screw 41 to the screw boss 40, it functions as a weight for norance.

According to this configuration, the flow collides with the screw 41 serving as a weight for balancing the rotation of the impeller 14. As a result, the air flow rate of the backflow 29 is limited, and the reduction of the blowing efficiency and the generation of the turbulent noise are suppressed. As a result, the blowing efficiency of the fan 1 and the impeller 14 is improved, and the noise is reduced.

Embodiment 9

FIG. 11 shows a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 9 of the present invention. The same components as those in Embodiments 1 to 8 are assigned the same reference numerals and detailed explanations thereof will be omitted. In a centrifugal fan 1 according to a ninth embodiment of the present invention, as shown in FIG. 11, the back plate 8 has a main portion 43 and a spiral plate 44. The main portion 43 is joined to the end 9 a of the side wall 9. The helical plate 44 has a helical shape which is inclined helically from the tongue 42 toward the discharge port 11. Furthermore, the height He of the side wall 9 gradually expands from the vicinity of the tongue 42 toward the discharge port 11. That is, the helical plate 44 has an axial position (height And has an axial position (height H) equivalent to that of the cylindrical wall 22 near the discharge port 11.

1 2

Thus, the blower 1 has the spiral plate 44 inclined from the tongue 42 toward the discharge port 11. For this reason, the flow 28 flowing out of the blade 18 collides with the spiral plate 44, whereby the flow direction changes in the direction of the discharge port 11. As a result, the blowing efficiency of the blower 1 is improved. Further, the spiral plate 44 has a position in the vicinity of the discharge port 11 equivalent to the axial position of the cylindrical wall 22. For this reason, the height in the rotational axis direction of the blower 1 is miniaturized. Furthermore, a spiral plate 44 is composed of the main body 43 and a separate part. As a result, the main body 43 is formed into a simple structure, such as a flat plate, for example, and the spiral plate 44 is also easily made of a flat plate as well. For this reason, the structure of the back plate 8 is simplified, and the manufacturing cost of the impeller 14 and the blower 1 is reduced.

Tenth Embodiment

FIG. 12 shows a centrifugal impeller 14 and a centrifugal fan 1 according to a tenth embodiment of the present invention. The same components as those in Embodiments 1 to 9 are assigned the same reference numerals and detailed explanations thereof will be omitted. In a centrifugal fan 1 according to a tenth embodiment of the present invention, as shown in FIG. 12, a back plate projection 45 is provided on the back plate 8 and the positions of the back plate 8 and the main plate 15 in the rotational axis 12 coincide. Has a configuration. The back plate projection 45 projects to the outside of the casing 10 concentrically with the impeller 14

According to this configuration, when a part of the flow flowing out of the blade 18 reverses to the back surface 21 of the main plate 15, the area in which the back plate 8 and the cylindrical wall 22 face the flow is increased. Thus, backflow is blocked and the amount of circulating flow 30 is reduced. Also, the flow 28 flowing out of the blade 18 is prevented from rapidly expanding, and in the flow 28, the occurrence of the expansion loss is suppressed. As a result, the blowing efficiency between the impeller 14 and the blower 1 is improved.

Embodiment 11

FIG. 13 shows a centrifugal impeller 14 and a centrifugal fan 1 according to Embodiment 11 of the present invention. The same components as in Embodiments 1 to 10 are assigned the same reference numerals and detailed explanations thereof will be omitted. The centrifugal fan 1 according to Embodiment 11 of the present invention, as shown in FIG. 13, has an outer diameter Dm force of 00 mm of the main plate 15, a blade outer diameter Dbo of 182 mm, and an outer diameter Dwo of the cylindrical wall 22 of 182 mm. It is. That is, the blower 1 has a relationship of Dm> Dbo = Dwo Is configured.

With this configuration, the flow area from the blade 18 gradually increases while the flow 28 flowing out of the blade 18 reaches the outer diameter of the main plate 15, and the wind speed is reduced. Therefore, the occurrence of the expansion loss caused by the rapid expansion of the flow is suppressed. At the same time, the strong swirling flow 46 generated around the cylindrical wall 22 is restrained from colliding with the flow 28 flowing out of the blade 18. The strong swirling flow 46 generated around the cylindrical wall 22 is generated by the side wall 9 of the casing 10 having a spiral shape. As a result, the air flow efficiency between the impeller 14 and the blower 1 is improved, and the noise is reduced.

Industrial applicability

The present invention provides a centrifugal impeller and a centrifugal fan whose cost is improved, noise is reduced, size is reduced, size is simplified and cost is reduced, and ventilation and ventilation equipment is provided. , Or used for air conditioning equipment etc.

Claims

The scope of the claims

[I] disc-shaped main plate,

A plurality of blades joined on the outer periphery side of the front side surface of the main plate and disposed in an annular shape; and an annular plate attached to the tip of the blade;

An is center blade including a cylindrical wall provided concentrically with the main plate on a back side surface of the main plate.

[2] The centrifugal impeller according to claim 1, wherein the main plate has a vent hole provided for circulating air in the main plate.

[3] The plurality of blades form a multi-blade impeller shape

The centrifugal impeller according to claim 1 or 2.

[4] The inner diameter of the blade and the outer diameter of the ventilation hole are the same size

The centrifugal impeller according to claim 2.

[5] The outer diameter of the blade and the outer diameter of the cylindrical wall are the same size

The centrifugal impeller according to claim 1.

[6] The centrifugal impeller according to claim 2, wherein the inner cylinder wall has an inner cylindrical wall and an outer cylindrical wall which have different outer diameters.

[7] The inner diameter of the inner cylindrical wall is the same size as the outer diameter of the vent hole

The centrifugal impeller according to claim 6.

[8] The cylindrical wall is formed of a sound absorbing material

The centrifugal impeller according to claim 1.

[9] The height of the cylindrical wall is 30% or more and 40% or less of the height of the blade

The centrifugal impeller according to claim 2.

[10] The main plate has a main plate projecting portion in which a portion on the inner side protrudes from the blade in a cone shape.

The centrifugal impeller according to claim 2.

[II] The junction where the main plate and the blade are joined is inclined radially outward toward the cylindrical wall side The centrifugal impeller according to claim 1.

[12] The outer diameter of the cylindrical wall gradually expands toward the tip of the cylindrical wall

The centrifugal impeller according to claim 1.

[13] A drain hole is provided in either one of the cylindrical wall and the main plate

The centrifugal impeller according to claim 1.

[14] A balance weight provided inside the cylindrical wall, further comprising

The centrifugal impeller according to claim 1.

[15] With centrifugal impeller,

An electric motor having a rotating shaft fixed to the centrifugal impeller;

And a casing for housing the motor.

The centrifugal impeller according to any one of claims 1 to 17, wherein

The main plate is fixed to the rotating shaft in the casing;

The casing is

A suction plate having a bellmouth-like suction opening,

A back plate facing the suction plate;

With spiral side walls,

A discharge port,

Have

Centrifugal blower.

[16] The distance between the suction port and the portion outside the centrifugal impeller on the back plate is larger than the distance between the main plate and the suction port,

The centrifugal blower according to claim 15.

[17] The back plate is a flat plate

The centrifugal fan according to claim 16.

[18] The casing is

It has a helical portion provided outside the centrifugal impeller of the back plate so that the casing height gradually expands from near the tongue toward the discharge port. The centrifugal blower according to claim 15.

[19] The spiral portion is formed at an axial position equivalent to the main plate in the vicinity of the tongue portion, and is formed at an axial position equivalent to the cylindrical wall at the discharge port.

A centrifugal fan according to claim 18.

[20] The spiral portion is configured as a separate part from the back plate

A centrifugal fan according to claim 18.

[21] The centrifugal impeller having a ventilation hole in the main plate is provided in the casing.

The centrifugal blower according to claim 15.

[22] The back plate has a back plate projection that protrudes to the outside of the casing concentrically with the centrifugal impeller.

The centrifugal fan according to claim 15, wherein the rotational axis direction position of the back plate and the rotational axis direction position of the main plate are the same.

[23] At least a part of the motor is contained inside the cylindrical wall

The centrifugal blower according to claim 15.

[24] The outer diameter of the main plate is larger than the outer diameter of the blade and larger than the outer diameter of the cylindrical wall.

The centrifugal blower according to claim 15.