JP2001182692A - Centrifugal air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrigugal air blower capable of improving performance and reducing noise. SOLUTION: In this centrifugal air blower provided with a rotary blade 2 for centrifugally blowing air by being rotated around the rotary blade axis by juxtaposing and providing plural blade parts 21 in the circumferential direction and a fan case 1 having an intake port 11 for sucking air in the rotary blade axis direction by surrounding the rotary blade 2 and an exhaust port 12 for exhausting air in the almost tangent direction to a rotary locus of the rotary blade 2, a swelling part 1B swelling outward in the rotary blade axis direction is formed on an inside surface of a side wall part 15a in the blade radial direction of the rotary blade 2 among an air duct forming part 1A for forming an air duct 13 continuing with the exhaust port 12 along the outer periphery of the rotary blade 2 in the fan case 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary blade provided with a plurality of blades arranged in a circumferential direction and rotated around an axis of the rotary blade to send centrifugal air, surrounding the rotary blade, and
A centrifugal machine provided with an intake port for sucking air along the axis of the rotating blades and a fan case having an exhaust port for discharging air along a direction substantially tangential to the rotation trajectory of the rotating blades. It relates to a type blower.

[0002]

2. Description of the Related Art Such a centrifugal blower is used, for example, for supplying combustion air to a gas burner of a water heater. Conventionally, as shown in FIG. 17, an air passage 13 in the fan case 1
Is formed along the blade radial direction of the rotary blade 2 and a pair of flat side wall portions respectively located at both ends in the direction of the rotary blade axis P of the rotary blade. 15a and a peripheral wall portion 14a connecting the pair of side wall portions 15a at outer ends in the blade radial direction. The intake port 11 is provided, for example, on one side of the fan case 1 in the axial direction of the rotating blade. And
When the rotary blades 2 are driven to rotate in the fan case 1 by an electric motor (not shown), the air sucked in the axial direction of the rotary blades from the intake port 11 by the rotation of the rotary blades 2 is rotated by the rotary blades 2. The air is pressurized while being centrifugally blown toward the air passage 13 in the radial direction of the blade, so that the air flows through the air passage 13 toward the exhaust port and is discharged from the exhaust port 12. In FIG. 17, reference numeral 21 denotes a blade of the rotary blade 2.

[0003]

Meanwhile, in such a centrifugal blower, as shown by an arrow f in FIG. 16, the blades of the rotary blade 2 are sucked in the axial direction of the rotary blades from the intake port 11. The air centrifugally blown outward in the radial direction is supplied to the air passage 13 by a pair of side walls 1.
5a and the peripheral wall portion 14a connecting them guide the swirl so as to be directed inward in the blade radial direction while being directed in the axial direction of the rotary blade.
3 spirally flows toward the exhaust port.

However, in the prior art, as shown in FIG. 17, since the pair of side walls 15a are formed in a flat shape, air collides with the inner surface of the flat side wall 15a and is reflected. The air reflected on the side wall portion 15a
Since the air collides with the air coming toward the inner surface of the air passage 13, turbulence occurs in the air flowing in the air passage 13, and it is difficult to form a stable spiral air flow in the air passage 13. Therefore, conventionally,
There is room for improvement in increasing the air flow and increasing the static pressure to improve the performance and reduce noise.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a centrifugal blower capable of improving performance and reducing noise.

[0006]

Means for Solving the Problems [Invention according to claim 1]
The characteristic configuration according to claim 1 is that, in the fan case, of the air path forming portion that forms the air path connected to the exhaust port along the outer periphery of the rotary blade, the air path extends along the blade radial direction of the rotary blade. A swelling portion swelling toward the outside in the axial direction of the rotary blade is formed on the inner surface of the side wall portion. According to the characteristic configuration of the first aspect, the air is centrifugally blown outward in the blade radial direction of the rotating blade, and the inside of the blade in the blade radial direction is directed in the air path in the axial direction of the rotating blade. Since the air flowing toward the side is guided by turning while the reflection is suppressed by the bulging portion of the side wall existing at the end of the flow, the occurrence of turbulent flow is suppressed,
A spiral flow is formed stably. Therefore, it is possible to improve the performance by increasing the air flow and increasing the static pressure and to reduce the noise, as compared with the related art.

According to a second aspect of the present invention, the side wall portion on which the bulging portion is formed is provided on a side wall of the fan case where an air inlet is formed. It is in. That is, the air sucked from the intake port in the axial direction of the rotary blade and centrifugally blown outward in the blade radial direction of the rotary blade flows in the air passage toward the air supply port in the axial direction of the rotary blade. Strong tendency toward. According to the characteristic configuration of the second aspect, since the side wall on which the bulging portion is formed is provided on the side wall of the fan case where the air inlet is formed, the bulging portion has a direction in which air easily flows. Therefore, the swing guide action is further increased since the swivel guide action is present at the side wall portion located at the end of the turn. Therefore, higher performance and lower noise can be further promoted as compared with the case where the side wall portion on which the bulging portion is formed is provided on the side wall of the fan case opposite to the intake port side.

[0008] According to a third aspect of the present invention, the side wall portion on which the bulging portion is formed is formed on a side wall of the fan case located on both sides in the axial direction of the rotary blade. Is to be provided. Claim 3
According to the characteristic configuration described in the above, since the bulging portion is present on both sides in the axial direction of the rotary blade, the air flowing in the air path toward both sides in the axial direction of the rotary blade, The swirl is guided by the located bulge to form two stable spiral flows. Therefore, higher performance and lower noise can be further promoted as compared with a configuration in which the bulging portion is provided only on one side in the axial direction of the rotary blade.

The invention according to claim 4 is characterized in that the bulging portion has a radially outer end portion of the blade in the blade radial direction end on an inner surface of the side wall portion. Part or near the part. According to the characteristic configuration of the fourth aspect, the bulging portion is:
Since the outer end in the radial direction of the blade is formed so as to be located at or near the radial end of the inner surface of the side wall portion, the outer radial end is directed outward in the radial direction of the rotary blade. The centrifugally blown air is efficiently swirled and guided, and a spiral flow is formed over a wide area in the transverse direction in the air path. Therefore, it is possible to provide a specific configuration preferable in terms of stabilizing the spiral flow of the air by increasing the function of guiding the swirling of the air.

The invention according to claim 5 is characterized in that the bulging portion has an inner end in the blade radial direction on the inner surface of the side wall portion outside the rotary blade. That is, it is formed so as to be located at a position corresponding to the peripheral edge or a position near the peripheral edge. According to the characteristic configuration of the fifth aspect, the bulging portion has a radially inner end portion of the blade in a position corresponding to an outer peripheral edge of the rotary blade on the inner surface of the side wall portion or a position near the position. , The air directed inward in the blade radial direction is efficiently swirled and guided, and a spiral flow is formed over a wide range in the transverse direction in the air path.

[0011] In particular, the bulging portion is formed in a state where the radially outer end of the blade is located at or near the blade radial end of the inner surface of the side wall. In this configuration, when the characteristic configuration of claim 5 is adopted, the bulging portion is formed over substantially the entire length in the blade radial direction on the inner surface of the side wall portion, so that the bulging portion is as wide as possible in the transverse direction in the air path. It is more effective in forming a swirling flow over a range. Therefore, it is possible to provide a specific configuration preferable in terms of stabilizing the spiral flow of the air by increasing the function of guiding the swirling of the air.

[0012] According to a sixth aspect of the present invention, the bulging portion is formed on the inner surface of the side wall portion.
The air passing through the air passage is formed on the inner surface of the side wall portion at least in a high-speed region corresponding to a high-speed region where the flow velocity along the longitudinal direction of the air passage is the fastest. According to the characteristic configuration of the sixth aspect, since the bulging portion exists corresponding to the high-speed region where the flow of the air tends to be turbulent, the air is efficiently swirled and guided, and the turbulence is suppressed. Is done. Therefore, it is possible to provide a specific configuration preferable in terms of stabilizing the spiral flow of the air by increasing the function of guiding the swirling of the air.

The invention according to claim 7 is characterized in that the bulging portion is formed on the inner surface of the side wall along the high-speed region and the high-speed region along the longitudinal direction of the air path. That is, it is formed at a place connected before and after the place. According to the characteristic configuration of the seventh aspect, the air is guided to turn in a range that includes the high-speed area and continues in the longitudinal direction of the air path. Therefore, it is possible to provide a specific configuration preferable in terms of stabilizing the spiral flow of the air by increasing the function of guiding the swirling of the air.

According to an eighth aspect of the present invention, in the characteristic configuration of the eighth aspect, the bulging portion has a bulging amount which is the largest in the high-speed region, and gradually decreases as the distance from the bulging portion increases. It is formed in a state. According to the characteristic configuration of the eighth aspect, in the flow path of the air along the longitudinal direction of the air path, the variation in the flow velocity of the air is reduced. Therefore, it is possible to provide a preferred specific configuration in terms of stabilizing the spiral flow of air.

According to a ninth aspect of the present invention, in the rotary blade, an annular body is provided at an end of the rotary blade in the axial direction of the rotary blade and at an outer circumferential end of the rotary blade in the radial direction of the blade. Is provided. According to the characteristic configuration of the ninth aspect, by the annular body, the cross-sectional area of the suction path for sucking air along the rotating blade axis direction, and the sucked air is directed outward in the blade radial direction. The plurality of blades can be connected while the cross-sectional area of the air flow path for centrifugal air blowing toward the air is widened as much as possible.

According to a tenth aspect of the present invention, in the annular structure, as the position of the annular body in the axial direction of the rotary blade is closer to the end, the annular body has a characteristic in the radial direction of the blade. An inclined guide surface whose position is located on the inner side is provided. According to the characteristic configuration of the tenth aspect, the air directed inward in the blade radial direction is guided by the inclined surface of the annular body. Therefore, it is possible to provide a specific configuration preferable in terms of stabilizing the spiral flow of the air by increasing the function of guiding the swirling of the air.

According to an eleventh aspect of the present invention, in the eleventh aspect of the present invention, there is provided a rotary blade shaft on an inward end portion of the bulging portion in the blade radial direction and an inclined guide surface of the annular body. The outer end in the core direction is located at the same position or a position close thereto in the blade radial direction. According to the characteristic configuration of the eleventh aspect, the air that is swirled and guided by the bulging portion when viewed in the wind path longitudinal direction,
Subsequently, the swivel is guided by the inclined surface of the annular body.
Therefore, it is possible to provide a specific configuration preferable in terms of stabilizing the spiral flow of the air by increasing the function of guiding the swirling of the air.

According to a twelfth aspect of the present invention, in the twelfth aspect, the intake port is formed on one of side walls of the fan case located on both sides in the axial direction of the rotary blade. Is to be. According to the twelfth aspect, the intake port is formed on only one of the side walls located on both sides of the fan case in the axial direction of the rotary blade, so that the configuration can be simplified. it can. In particular, in a configuration in which the side wall portion on which the bulging portion is formed is provided on the side wall on which the intake port is formed in the fan case, the configuration is simplified by adopting the characteristic configuration of claim 12. It is possible to promote higher performance and lower noise while improving the performance.

According to a thirteenth aspect of the present invention, the intake port is provided on a side wall of the fan case located on both sides in the axial direction of the rotary blade. . According to the characteristic configuration of the thirteenth aspect, since air is sucked from both sides in the axial direction of the rotary blade, the amount of air suction can be increased and the amount of air blown can be increased. In particular, in the configuration in which the side wall portion on which the bulging portion is formed is provided on the side wall of the fan case located on both sides in the axial direction of the rotating blade, the characteristic configuration of claim 13 is employed. Then, since the air sucked from the air supply ports on both sides is swirled and guided by the bulging portion on the same side as the side where the respective air intake ports exist, two spiral flows are formed as stably as possible. Above is preferred.

According to a fourteenth aspect of the present invention, the rotary blade is provided with a partition portion for partitioning between adjacent blade portions in the axial direction of the rotary blade. is there. According to the characteristic configuration described in claim 14, the air sucked in the axial direction of the rotary blade is suppressed by the partitioning portion from flowing toward the lower side in the suction direction, and is prevented from flowing in the axial direction of the rotary blade. It flows into the wind path in a diverted state. Therefore, the air flows toward the exhaust port in a state in which the variation in the flow rate in the cross direction of the air path is small, so that the air becomes easy to flow and the air volume can be increased.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. In addition, (a) of FIG. 1 shows a rotating blade axis P of the rotating blade 2.
(B) is a cross-sectional view along the direction of the rotating blade axis P at a position passing through the rotating blade axis P and the high-speed region 1E (details will be described later). As shown in FIG. 1, the centrifugal blower includes a fan case 1, a rotating blade 2 housed and held in the fan case 1, and a rotating blade 2
Is provided with an electric motor 3 that is driven to rotate around the rotating blade axis P (hereinafter, sometimes simply referred to as the rotating blade axis center).

The rotary blade 2 is provided with a large number of blade portions 21 arranged in the circumferential direction, and is configured to be rotated around the rotary blade axis and centrifugally blown. The fan case 1 surrounds the rotating blades 2 and has a suction port 11 for sucking air in a direction of the rotating blade axis P (hereinafter, may be simply referred to as a rotating blade axis direction). An exhaust port 12 that exhausts air in a direction tangential to the rotation trajectory is provided, and an air passage 13 connected to the exhaust port 12 is formed along the outer periphery of the rotary blade 2. The electric motor 3 drives the rotary blade 2 in the fan case 1 in the direction indicated by the arrow R in FIG. 1 to rotate the rotary blade 2 from the intake port 11 in the axial direction of the rotary blade. Is pressurized while centrifugally blowing air toward the air passage 13 in the blade radial direction of the rotating blade 2,
The air flows through the air passage 13 toward the exhaust port 12,
2 to be discharged.

The description of the fan case 1 will be added. When viewed from the axial direction of the rotary blade axis, the fan case 1 has both ends located apart from each other to form the exhaust port 12, and has a peripheral wall 14 along the outer periphery thereof at a distance from the outer peripheral edge of the rotary blade 2. And a pair of side walls 15, which are continuous with the respective side edges of the peripheral wall 14 in the axial direction of the rotary blade at the respective peripheral edges, are positioned in a posture along the blade radial direction of the rotary blade 2, and face each other. It is.

One of the pair of side walls 15 has an inlet 1
In order to function as 1, a circular opening centered on the rotary blade axis P is formed. The peripheral wall 14 includes the rotating blade 2
Is bent inwardly inward to form a tongue 16 for separating the base end and the end of the air passage 13 from the tongue 16 to the other end. The position is gradually increased toward the rotating blade axis P. The rectangular exhaust port 1 is formed by both edges of the peripheral wall 14 and edges of each of the pair of sidewalls 15.
The air path 13 is formed by the peripheral wall 14 and the pair of side walls 15 so as to be continuous with the exhaust port 12 and along the outer periphery of the rotary blade 2. It is formed so that the width in the direction becomes wider.

In the fan case 1, an air path forming portion 1 A forming the air path 13 is formed by a pair of side walls 15 a which are made to function by a pair of side walls 15 and extend in the blade radial direction of the rotary blade 2.
And a peripheral wall portion 14a functioning on the peripheral wall 14 and extending along the axis of the rotating blade.

In the present invention, the inner surface of the side wall portion 15a of the fan case 1 along the blade radial direction of the rotating blade 2 of the air passage forming portion 1A forming the air passage 13 is provided in the axial direction of the rotating blade. A bulging portion 1B bulging outward is formed. In the first embodiment, the side wall portion 15a forming the bulging portion 1B is provided on the side wall 15 on which the intake port 11 is formed, of the pair of side walls 15 in the fan case 1. .

The bulging portion 1B is located at a high-speed area corresponding to a high-speed area 13E where the flow rate of air flowing through the air path 13 along the longitudinal direction of the air path is the fastest on the inner surface of the side wall 15a.
And, it is formed at a place that continues before and after the high-speed area along the wind path longitudinal direction. When the tongue 16 is set as a reference position and the rotation angle from the tongue 16 to the rotation direction R of the rotary blade 2 is defined as a winding angle θ, in the centrifugal blower of the present embodiment, the high-speed region 13E has a winding angle of θ exists in a portion centered at about 290 °. The bulging portion 1B is formed so that the winding angle θ ranges from 85 ° to 340 °.

Further, the bulging portion 1B has its outer end in the blade radial direction close to the radial end of the blade on the inner surface of the side wall portion 15a within a range extending over substantially the entire length in the longitudinal direction of the air path. And the inner end of the blade in the blade radial direction is located on the inner surface of the side wall portion 15a.
Is formed at a position corresponding to the outer peripheral edge of.

The bulging portion 1B is formed in such a state that the bulging amount is the largest at the high-speed region, and gradually decreases as the bulging portion moves further away in the longitudinal direction of the air path.
That is, the bulging portion 1B is formed in a curved surface shape in which the bulging height is the highest in the approximate center of the blade radial direction and gradually decreases as the distance from the blade radial direction increases. The bulging portion 1B is formed in such a manner that the height of the highest portion at the approximate center in the blade radial direction is the highest in the high-speed region, and gradually lowers as it moves away from the blade in the longitudinal direction of the air path. The cross-sectional area in the blade radial direction is the widest at the high-speed region and gradually narrows as the distance from the blade in the longitudinal direction of the air path increases.

The bulging portion 1B is formed by forming the plate-like side wall portion 15a so as to bulge.

The rotating blade 2 will be described. FIG.
As shown in FIG. 2, the rotating blade 2 has a large number of plate-like blade portions 21 arranged in a ring around each of both surfaces of an annular partition plate 24, and has an annular shape on one surface of the partition plate 24. The other end of the blade portion 21 held at the end is connected by a disk-shaped rotary plate 22 at the edge of each rotary blade axial direction end, and is annularly connected to the other surface of the partition plate 24. The other end of the blade portion 21 held at the end is connected to an annular body 23 at an end portion in the axial direction of the rotary blade and at an outer peripheral end portion in the radial direction of the blade. is there. The vanes 21 arranged annularly on both sides of the partition plate 24 are configured so that their arrangement phases are different from each other.

That is, at the end of the rotary blade 2 in the axial direction of the rotary blade and at the outer peripheral end in the radial direction of the blade,
An annular body 23 is provided, and in the annular body 23, as the position in the axial direction of the rotary blade is closer to the end portion, the position in the radial direction of the blade is located closer to the inner side; A curved inclined guide surface 23g bulging inward in the radial direction is provided.

The partition plate 24 functions as a partition part that partitions the space between the blade portions 21 adjacent in the circumferential direction in the axial direction of the rotary blade. The partition plate 24 has an outer end in the blade radial direction located at the same or substantially the same position as the outer end in the blade radial direction of the blade 21 in the blade radial direction,
The inner side in the radial direction of the blade is inclined such that the position in the axial direction of the rotary blade is located closer to the annular body 23 as the position in the radial direction of the blade is closer to the inner side. Part 21
And projecting more inward in the blade radial direction.

The rotating blades 2 are manufactured in the above-described shape by, for example, resin molding. The rotary blade 2 is fixedly held on a rotary shaft 31 of the electric motor 3 via a rotary plate 22 so as to rotate around the rotary blade axis.

The electric motor 3 is fixed to the side wall 15 with the rotary blade 2 in a position in which the annular body 23 is positioned on the side of the intake port 11 and the rotary blade axis P is positioned substantially in the center of the intake port 11. By doing so, it is held in the fan case 1.

The diameter of the intake port 11 formed in the side wall 15 is made smaller than the diameter of the inclined guide surface 23g of the annular body 23 on the outer side end in the axial direction of the rotary blade, and the diameter of the bulging portion 1B is reduced. A radially inward end portion of the blade and an annular body 2
The outer end of the third inclined guide surface 23g in the axial direction of the rotary blade is located at a position close to the same position in the blade radial direction.

Next, based on FIG. 3 and FIG. 4, the result of comparing the performance between the centrifugal blower according to the present invention and the conventional centrifugal blower will be described. However, for easy comparison,
In the conventional centrifugal blower, the rotating blade 2 is the same as the rotating blade 2 of the present invention described above. 3 and 4
In each case, (a) shows the measurement result of the present invention, and (b) shows the measurement result of the conventional one. FIG. 3 shows the high-speed area 13 of the air path 13 when viewed from the exhaust port 12 side.
E shows the result of measuring the direction of air flow and the turbulence with a laser Doppler velocimeter (hereinafter abbreviated as LDV) in E, showing the direction of air flow with an arrow f, and showing the turbulence of air flow. Strong parts are indicated by hatching h. FIG. 4 shows the blade viewed from the outside in the blade radial direction.
The direction of the air flow in the high-speed area 13E of the wind path 13 and the vicinity thereof is shown, and the result of measuring the turbulence by the LDV is shown. The direction of the air flow is shown by an arrow f, and the turbulence of the air flow is shown. Strong parts are indicated by hatching h.

As shown in FIG. 3A, in the centrifugal blower of the present invention, the air is sucked from the intake port 11 in the axial direction of the rotating blades and outwardly in the blade radial direction of the rotating blades 2. The air that has been centrifugally blown toward the air passage 13 toward the air supply port 11 in the direction of the axis of the rotating blades is centrifugally blown toward the air supply port 11 in a state where reflection is suppressed by the bulging portion 1B of the side wall portion 15a. While being directed inward in the direction, the swirl is guided toward the opposite side to the air supply port 11 side in the axial direction of the rotary vane, so that a smooth spiral flow is formed, and FIG. As shown in FIG. 3, the flow toward the exhaust port 12 becomes smooth, and as shown in FIG. 3 and FIG.

On the other hand, as shown in FIG. 3 (b), in the conventional centrifugal blower, the air is sucked from the intake port 11 in the axial direction of the rotating blade, and is drawn in the radial direction of the rotating blade 2. The air that is centrifugally blown outward and heads in the air passage 13 toward the air supply port 11 in the axial direction of the rotating blades collides with the flat side wall portion 15a and is reflected. No flow is formed, and as shown in FIG.
The flow toward the exhaust port 12 is also disturbed, and as shown in FIG. 3 and FIG.

Further, the centrifugal blower according to the first embodiment of the present invention and a conventional centrifugal blower are provided in a hot water supply device,
The apparatus was operated so as to have a pressure loss of 196 Pa and a flow rate of 1200 liter / min, and the rotation speed and the noise level were measured and compared for each. Note that the noise level was measured by the characteristic A of the auditory correction circuit. The rotation speed is 3 in the present invention.
370 rpm, whereas the conventional one is 358 rpm
0 rpm, and the noise level is 5 in the present invention.
6.8 dB, whereas the conventional one is 59.3
dB. The centrifugal blower according to the present invention can obtain the same amount of flow at a smaller number of rotations as compared with the conventional centrifugal blower, so that the performance is improved and the noise level is reduced to 2.5.
Since the noise is reduced by about dB, the noise can be reduced.

Further, the centrifugal blower of the present embodiment has various functions as described in (a) to (e) below. (A) Since the rotary blade 2 is provided with the partition plate 24 as described above, the air sucked from the intake port 11 in the axial direction of the rotary blade is diverted in the axial direction of the rotary blade. Flows into the air passage 13 and flows in a state in which the variation in the flow rate in the cross direction of the air passage 13 is reduced. Further, the inner side of the partition plate 24 in the blade radial direction is such that, as the position in the blade radial direction is closer to the inner side, the position in the axial direction of the rotary blade is closer to the annular body 23 (ie, The air suctioned in the axial direction of the rotary blade from the air inlet 11 is performed by the inclined shape located on the side of the air inlet 11) and protruding inward in the blade radial direction from the blade portion 21. The flow can be smoothly divided in the axial direction of the rotating blades, and turbulence is prevented.

(B) Since the bulging portion 1B is formed on the inner surface of the side wall portion 15a over a long range in the longitudinal direction of the air path including the high-speed region, air flows along the longitudinal direction of the air path. The swirl is guided by the bulging portion 1B over a long range of the route. (C) Since the bulging portion 1B is formed in such a state that the bulging amount is the largest at the high-speed region and gradually decreases as the bulging portion moves away from the high-speed region, the bulging portion 1B communicates with the air flowing through the air passage 13. Fluctuations in the flow velocity in the flow path direction are reduced. (D) The bulging portion 1B has its outer end in the blade radial direction located near the blade radial direction end on the inner surface of the side wall portion 15a within a range extending over substantially the entire length in the air path longitudinal direction. And the inner end of the blade in the radial direction is located at a position corresponding to the outer peripheral edge of the rotary blade 2 on the inner surface of the side wall portion 15a. And a spiral flow is formed over a wide range in the transverse direction of the air passage 13. (E) The inner end of the bulging portion 1B in the blade radial direction and the outer end of the inclined guide surface 23g of the annular body 23 in the axial direction of the rotary blade are the same in the radial direction of the blade. Since it is located at a position close to the position, the air guided by the swollen portion 1b in the longitudinal direction of the air path is subsequently guided by the slant guide surface 23g of the annular body 23. Thus, a more stable spiral flow is formed. By the synergistic effect of each of the above-described actions (a) to (e), a stable spiral flow is formed over substantially the entire length of the flow path along the longitudinal direction of the air path.

Hereinafter, the second to eleventh embodiments of the present invention will be described. The same reference numerals are used for the same components and components having the same functions as those of the first embodiment in order to avoid redundant description. The description will be omitted by attaching them, and mainly the configuration different from the first embodiment will be described.

[Second Embodiment] Hereinafter, based on FIG.
A second embodiment of the present invention will be described. Arrow f in FIG.
Indicates the flow direction of the air measured by the LDV. In the second embodiment, the side wall portion 15 where the bulging portion 1B is formed is formed.
“a” is provided on each of the pair of side walls 15 of the fan case 1, and the other configuration is the same as that of the first embodiment. Therefore, as shown by the arrow f in FIG. 5, the air is swirled and guided by the bulging portions 1B on both sides, and two stable spiral flows are formed. Noise can be reduced.

[Third Embodiment] Hereinafter, based on FIG.
A third embodiment of the present invention will be described. Arrow f in FIG.
Indicates the flow direction of the air measured by the LDV. In the third embodiment, in the configuration of the above-described second embodiment, the corner portions are eliminated by connecting the pair of side wall portions 15a and the peripheral wall portion 14a in a curved shape. Side wall 15a
The air is guided in the swirling direction also in the curved continuous portion between the inner wall and the peripheral wall portion 14a, so that two more stable spiral flows are formed than in the second embodiment.

[Fourth Embodiment] Hereinafter, based on FIG.
A fourth embodiment of the present invention will be described. Arrow f in FIG.
Indicates the flow direction of the air measured by the LDV. In the fourth embodiment, the bulging portion 1B is further formed on the peripheral wall portion 14a in the second embodiment, and the bulging portion 1B of the peripheral wall portion 14a and the side wall portions 15 on both sides thereof are formed.
Each of the bulging portions 1B is connected in series so as to form a continuous curved surface. Therefore, the turning guide action is further increased as compared with the above-described second embodiment.
Two more stable spiral flows are formed.

[Fifth Embodiment] Hereinafter, based on FIG.
A fifth embodiment of the present invention will be described. In FIG. 8, arrow f
Indicates the flow direction of the air measured by the LDV. In the fifth embodiment, the partition plate 24 of the rotary blade 2 is omitted, and the blade portion 21 is formed as a series on the rotary blade axis. The other configuration is the same as that of the first embodiment. Therefore, since the partition plate 24 is omitted, the air slightly flows in the air passage 13 to the side opposite to the intake port 11 side in the direction of the rotary blade axis, so that the performance is slightly lower than in the first embodiment. However, the cost can be reduced by omitting the partition part 24.

[Sixth Embodiment] Hereinafter, based on FIG.
A sixth embodiment of the present invention will be described. Arrow f in FIG.
Indicates the flow direction of the air measured by the LDV. In the sixth embodiment, the intake port 11 is provided on the side wall 15 located on both sides of the fan case 1 in the axial direction of the rotating blades, and the rotating plate 22 is provided with an opening for intake. , In the same manner as the first embodiment.
Since the air is sucked from both sides in the axial direction of the rotary blade, the flow dividing action of the partition portion 24 of the rotary blade 2 can be more effectively promoted. Therefore, since the variation in the flow rate in the cross direction of the air passage 13 can be reduced as compared with the first embodiment, a more stable spiral flow is formed.

Seventh Embodiment A seventh embodiment of the present invention will be described below with reference to FIG. In FIG.
Arrow f indicates the direction of air flow measured by the LDV.
In the seventh embodiment, the intake port 11 is provided on the side walls 15 located on both sides of the fan case 1 in the axial direction of the rotating blades.
, The rotary plate 22 is provided with an opening for intake, and the side wall portion 15a on which the bulging portion 1B is formed.
Is provided on each of the pair of side walls 15 in the fan case 1 and has an annular body 23 having an inclined guide surface 23g.
Is configured to be provided on both sides in the axial direction of the rotating blades,
Otherwise, the configuration is the same as that of the first embodiment. Since air is sucked from both sides in the axial direction of the rotating blade,
The branching action of the partitioning portion 24 of the rotary blade 2 can be more effectively promoted, and the variation in the flow rate in the cross direction of the air passage 13 can be reduced.
The turning guide is provided by the bulges 1B on both sides. Therefore, two more stable spiral flows are formed, so that performance can be further improved and noise can be reduced.

[Eighth Embodiment] Hereinafter, FIGS.
An eighth embodiment of the present invention will be described with reference to FIG.
In FIG. 13, the direction of air flow measured by the LDV is indicated by an arrow f, and the places where air flow is strongly disturbed are indicated by hatching h. In the eighth embodiment, the annular body 23 of the rotary blade 2 covers only the edge of the outer edge of the blade 21 along the axis direction of the rotary blade, and the edge of the blade 21 along the radial direction of the blade is The annular body 21 has an outer peripheral surface whose position in the radial direction of the blade is substantially constant in the axial direction of the rotary blade. Other than that, the annular body 21 is the same as the first embodiment. It is composed. Therefore, in the eighth embodiment, since the annular body 23 is not provided with the inclined guide surface 23g as in the first embodiment, the turning guide effect is slightly reduced as compared with the first embodiment. As shown in the figure, there are a few places where the turbulence of the air flow is strong, although the number is smaller than in the related art, but the configuration of the rotary blade 2 can be simplified.

Then, the centrifugal blower according to the eighth embodiment was mounted on a water heater and operated in the same manner as in the first embodiment, and the rotation speed and noise level were measured. The rotation speed was 3370 rpm, and the noise value was The level was 57.9 dB. Therefore, the centrifugal blower according to the eighth embodiment has the first
Although the noise level is slightly higher than in the embodiment,
The same performance can be obtained, and the performance can be improved and the noise can be reduced as compared with the related art.

[Ninth Embodiment] Hereinafter, a ninth embodiment of the present invention will be described with reference to FIG. In the ninth embodiment, each of the blades 21 of the rotary blade 2 is formed in a shape in which an end of the rotary blade in the axial direction and an outer corner in the blade radial direction are cut off. The eighth embodiment includes an inclined edge 21e whose position in the radial direction of the blade is located closer to the inner side as the position in the axial direction of the rotating blade is closer to the end. Except that the same annular member 23 was provided as in the eighth embodiment.
The configuration is the same as that of the first embodiment.

Accordingly, when viewed in the longitudinal direction of the air path, the bulging portion 1b
Since the air guided in the turn is continuously guided in the inclined edge 21e of each blade portion 21 as shown by an arrow f in FIG. 14, the turn guide is more effective than in the eighth embodiment. The effect is increased and a stable spiral flow is formed.

[Tenth Embodiment] Hereinafter, a tenth embodiment of the present invention will be described with reference to FIG. In the tenth embodiment, the rotary blade 2 is configured in the same manner as the eighth embodiment, and the opening edge of the intake port 11 formed on the side wall 15 is
With respect to a corner portion of the blade portion 21 of the rotary blade 2 on the inner side in the blade radial direction, on the inner side in the blade radial direction, and
The configuration is the same as that of the first embodiment except that it is located at a position on the inner side in the axial direction of the rotary blade.

Therefore, the air flowing through the air passage 13 is prevented from leaking to the outside from the gap between the end of the blade 21 of the rotary blade 2 in the axial direction of the rotary blade and the side wall 15,
Since the turbulence of the air is suppressed, a more stable spiral flow is formed than in the eighth embodiment.

[Eleventh Embodiment] Hereinafter, an eleventh embodiment of the present invention will be described with reference to FIG. In the eleventh embodiment, the annular body 23 of the rotary blade 2 has a cross-sectional shape so as to cover from the outer edge of the blade portion 21 along the rotary blade axis direction to the edge along the blade radial direction. Is formed in the same manner as the first embodiment, except that is formed in an L-shape.

Therefore, the edge of each blade 21 arranged at an interval is covered by the annular body 23 and the turbulence of the air is suppressed, so that the spiral flow is more stable than in the eighth embodiment. Is formed.

[Another Embodiment] Next, another embodiment will be described. (A) The formation range of the bulging portion 1B in the longitudinal direction of the air path is not limited to the range illustrated in the above embodiment, and may be longer than the range illustrated in the above embodiment, It may be shorter. However, it is preferable to form the inner surface of the side wall 15a in a range including a high-speed area corresponding to the high-speed area 13E of the air passage 13.
Further, the formation range of the bulging portion 1B in the blade radial direction is not limited to the range exemplified in the above embodiment. For example, the outer side end of the blade in the radial direction is
5a is located at the blade radial direction end on the inner surface, and the blade radial direction inner side end is the outer circumferential end of the rotating blade axis direction on the inclined guide surface 23g of the annular body 23, and You may form so that it may be located in the same position in a blade radial direction. Further, the present invention is not limited to the range over the entire length in the blade radial direction, and may be formed partially in the blade radial direction, but is preferably formed over the range as long as possible in the blade radial direction.

(B) In each of the second to seventh embodiments, the partition plate 24 of the rotary blade 2 may be omitted. In each of the third and fourth embodiments, when the intake port 11 is provided on the side wall 15 located on both sides of the fan case 1 in the axial direction of the rotating blade,
A more stable spiral flow can be formed. In each of the eighth, ninth, tenth and eleventh embodiments, the side wall portion 15a where the bulging portion 1B is formed is the fan case 1
If it comprises so that it may be provided in each of a pair of side wall 15 in, a more stable spiral flow can be formed.
Further, in this case, if the intake ports 11 are provided on the side walls 15 located on both sides of the fan case 1 in the axial direction of the rotating blades, a more stable spiral flow can be formed.

(C) In the rotary blade 2, the number of partition plates 24 provided in the axial direction of the rotary blade is not limited to one, but may be two or more.

(D) In each of the first to sixth embodiments, the annular body 23 having the inclined guide surface 23g is
It may be provided on both sides in the axial direction of the rotating blade. In this case, since the turning guide action increases, a more stable spiral flow is formed.

(E) In the case where the rotary blade 2 is provided with the partition plate 24, the partition plate 24
Although the arrangement phase of the blade portions 21 arranged annularly on both sides of each is different from each other on both sides, they may be configured to be the same as each other.

(F) In the air path 13, the high-speed area 13
E is not limited to the position exemplified in the above-described embodiment, but exists at various positions in the longitudinal direction of the air path according to the shape of the air path 13 and the like.
It is formed corresponding to the position of the high-speed area 13E.

(G) In each of the above embodiments, the bulging portion 1B is formed by forming the plate-like side wall portion 15a so as to bulge.
5a is constituted by a thick member, and the thick side wall portion 15a is formed.
On the other hand, a concave groove that functions as the bulging portion 1B may be formed so that the side of the side wall 15a opposite to the bulging portion 1B has a flat surface.

(H) The centrifugal blower according to the present invention can be used in various applications such as a bathroom dryer, a ventilator, and an air conditioner, in addition to the hot water supply device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a centrifugal blower according to a first embodiment.

FIG. 2 is a perspective view showing rotating blades of the centrifugal blower according to the first embodiment.

FIG. 3 is a diagram showing the direction and turbulence of air flowing through an air passage;

FIG. 4 is a diagram showing the direction and turbulence of air flowing through an air passage;

FIG. 5 is a cross-sectional view of a centrifugal blower according to a second embodiment, taken along a rotating blade axis.

FIG. 6 is a cross-sectional view of a centrifugal blower according to a third embodiment, taken along a rotating blade axis.

FIG. 7 is a cross-sectional view of a centrifugal blower according to a fourth embodiment, taken along a rotating blade axis.

FIG. 8 is a cross-sectional view of a centrifugal blower according to a fifth embodiment, taken along a rotating blade axis.

FIG. 9 is a cross-sectional view of a centrifugal blower according to a sixth embodiment, taken along a rotating blade axis.

FIG. 10 is a cross-sectional view of a centrifugal blower according to a seventh embodiment, taken along a rotating blade axis.

FIG. 11 is a cross-sectional view of a centrifugal blower according to an eighth embodiment, taken along a rotating blade axis.

FIG. 12 is a perspective view showing a rotary blade of a centrifugal blower according to an eighth embodiment.

FIG. 13 is a diagram showing the direction and turbulence of air flowing through an air passage in a centrifugal blower according to an eighth embodiment.

FIG. 14 is a cross-sectional view of a centrifugal blower according to a ninth embodiment, taken along a rotating blade axis.

FIG. 15 is a cross-sectional view of a centrifugal blower according to a tenth embodiment, taken along a rotating blade axis.

FIG. 16 is a cross-sectional view of a centrifugal blower according to an eleventh embodiment along the axis of a rotating blade.

FIG. 17 is a cross-sectional view of a conventional centrifugal blower taken along a rotating blade axis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fan case 1A Air path forming part 1B Swelling part 2 Rotating blade 11 Intake port 12 Exhaust port 13 Air path 13E High-speed area 15 Side wall 15a Side wall part 21 Blade part 23 Annular body 23g Inclined guide surface 24 Partition part

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masashi Nishigaki 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Tetsuji Morita 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka 1-2-2 Osaka Gas Co., Ltd. (72) Inventor Hiroshi Kamiya 1-1-52 Oka, Minami-shi, Minato-ku, Osaka-shi, Osaka Herman Co., Ltd. (72) Soichiro Asada 100 Kutoku-cho, Ogaki-shi, Gifu Pacific Industry Co., Ltd. (72) Inventor Yasushi Hishida 100, Kutoku-cho, Ogaki-shi, Gifu Prefecture Pacific Industrial Co., Ltd. (72) Inventor Shinichi Tanaka 100, Kutoku-cho, Ogaki-shi, Gifu Pacific Industrial Co., Ltd. F-term (reference) 3H033 AA02 AA18 BB02 BB06 BB20 CC01 CC03 DD04 DD06 DD09 DD29 EE06 EE08 3H034 AA02 AA18 BB02 BB06 BB20 CC03 DD05 DD08 EE06 EE08

Claims (14)

[Claims] 1. A method comprising: providing a plurality of blades arranged in a circumferential direction;
A rotary blade that is rotated around the rotary blade axis and centrifugally blows the air; and an intake port for surrounding the rotary blade and sucking air along the rotary blade axis direction and a rotation locus of the rotary blade. A fan case provided with an exhaust port for discharging air along a substantially tangential direction with respect to the centrifugal blower, wherein an air passage connected to the exhaust port in the fan case is provided on an outer periphery of the rotary blade. A bulging portion that bulges outwardly in the axial direction of the rotating blade is formed on an inner surface of a side wall portion along a blade radial direction of the rotating blade, of an air path forming portion formed along the rotating blade. Centrifugal blower. 2. The centrifugal blower according to claim 1, wherein the side wall on which the bulging portion is formed is provided on a side wall of the fan case where an air inlet is formed. 3. The centrifugal blower according to claim 1, wherein side walls on which the bulging portions are formed are provided on side walls of the fan case located on both sides in the axial direction of the rotary blade. 4. The swelling portion is formed in a state where its radially outer end portion is located at or near the blade radial end portion on the inner surface of the side wall portion. The centrifugal blower according to any one of claims 3 to 3. 5. The bulging portion is formed in a state in which the radially inner end of the blade is located at a position corresponding to the outer peripheral edge of the rotary blade on or near the inner surface of the side wall portion. The centrifugal blower according to any one of claims 1 to 4, wherein: 6. The bulging portion is provided at least in a high-speed region corresponding to a high-speed region in which the flow velocity of air passing through the air passage along the longitudinal direction of the air passage is highest on the inner surface of the side wall portion. The centrifugal blower according to any one of claims 1 to 5, wherein the blower is formed on an inner surface of the side wall portion in a state. 7. The swelling portion according to claim 6, wherein the bulging portion is formed at a location on the inner surface of the side wall portion, which is continuous with the high-speed area along the longitudinal direction of the air path before and after the high-speed area. Centrifugal blower. 8. The centrifugal blower according to claim 7, wherein the bulging portion is formed such that the bulging amount is the largest at the high-speed region and gradually decreases as the distance from the bulging portion increases. 9. The rotating blade according to claim 1, wherein an annular body is provided at an end in the axial direction of the rotating blade and at an outer peripheral side end in the radial direction of the blade. The centrifugal blower as described. 10. The annular body is provided with an inclined guide surface whose position in the radial direction of the blade is closer to the inner side as the position in the axial direction of the rotary blade is closer to the end. The centrifugal blower according to claim 9. 11. An inner end of the bulging portion in the blade radial direction and an outer end of the slant guide surface of the annular body in the axial direction of the rotary blade are arranged in the radial direction of the blade. The centrifugal blower according to claim 10, which is located at the same position or a position close thereto. 12. The centrifugal type according to claim 1, wherein the intake port is formed on one of side walls located on both sides of the fan case in the axial direction of the rotary blade. Blower. 13. The centrifugal blower according to claim 1, wherein the intake port is provided on a side wall located on both sides of the fan case in the axial direction of the rotating blade. 14. The centrifugal blower according to claim 12, wherein said rotary blade is provided with a partition portion for partitioning between adjacent blade portions in the axial direction of said rotary blade.