JP2000146214A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress increase in the turbulence of air flow when an air conditioner is operated under high static pressure conditions by extending the suction side front edge of a vane in the impeller of a centrifugal fan farther than the front edge position of the vane at other part and forming a substantially triangular protrusion projecting to the inner diameter side of the impeller. SOLUTION: The impeller 10 of a centrifugal fan comprises a plurality of vanes 11, a main plate 12 fixed with the vanes 11, and a side plate 13 having a suction opening secured to the end face of the vane 11 on the side opposite to the main plate. A substantially annular heat exchanger is disposed on the delivery side of the impeller 10 and secured in a easing along with the impeller 10. Diameter Ds of air inlet in the side plate 11 is set larger than the vane inlet diameter D1 and the suction side front edge of the vane 11 is projected farther than the front edge position of the vane at other part to the inner diameter side of the impeller to form a substantially triangular protrusion 11a. Forward end 11b of the protrusion 11a is set between the air inlet 13a in the side plate 13 and D-D cross-section parallel with the main plate 12 including the joint of the rear edge of the vane 11 and the side plate 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in performance of an air conditioner provided with an impeller of a centrifugal blower.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for downsizing, high performance, and low noise of an air conditioner having a centrifugal fan impeller, and the shape of the centrifugal fan impeller and the sectional shape of the impeller have been improved. For example, various performance improvement methods have been proposed.

A conventional air conditioner equipped with an impeller of a centrifugal blower is disclosed in Japanese Utility Model Laid-Open No. 2-69097.

Hereinafter, the above-described conventional air conditioner will be described with reference to the drawings. FIG. 13 is a sectional view showing the structure of a conventional air conditioner, FIG. 14 is a sectional view showing the structure of an impeller of a centrifugal blower mounted on the conventional air conditioner, and FIG. It is AA sectional drawing which shows a shape.

In FIG. 1, reference numeral 1 denotes an impeller of a centrifugal blower, which includes a plurality of blades 2 and a circular main plate 3 to which the blades 2 are fixed.
And a side plate 4 having a suction port fixed to the end face of the blade plate 2 on the side opposite to the main plate. Reference numeral 5 denotes an electric motor directly connected to the impeller 1, and reference numeral 6 denotes a substantially annular heat exchanger disposed on the outlet side of the impeller 1, which is housed and fixed together with the impeller 1 in a casing 7. Reference numeral 8 denotes a suction ring fixed to the casing. The suction ring 8 is curved from an inlet end 8a to an outlet end 8b, and the outlet end 8b is connected to the impeller 1.
Is inserted into the side plate 4.

Further, the suction diameter Ds of the side plate 4 is
Is larger than D1 than the blade inlet diameter of the blade, and the cross-sectional shape obtained by cutting the blade plate 2 on the inner diameter side from the suction diameter Ds by a plane parallel to the rotation axis of the impeller 1 is as follows:
The height h1 of the upper end of the rotation direction surface 2a of the blade plate 2 is larger than the height h2 of the upper end of the counter rotation direction surface 2b.

Further, in the blade section orthogonal to the rotation axis of the impeller 1, the blade section in the vicinity of the main plate 3 to the blade section in the vicinity of the side plate 4 have substantially the same blade sectional shape.

The operation of the air conditioner configured as described above will be described below. First, when the impeller 1 rotates in a predetermined rotation direction by the driving force of the electric motor 5, air flows into the impeller 1 through the suction ring 8, and when passing between the plurality of impellers 2, a static pressure is applied. And a dynamic pressure, and further heated or cooled when passing through the heat exchanger 6,
The air is blown out from the air outlet 9 and functions to adjust the indoor temperature and the indoor humidity.

At this time, since the suction diameter Ds of the side plate 4 is set to be larger than the blade inlet diameter D1, the suction port area becomes large, and the flow velocity of the suction airflow decreases. Therefore,
The flow resistance (loss) into the impeller 1 and the flow resistance (loss) inside the impeller 1 are reduced, and the air volume is increased at the operating point where the pressure is low, so that the blowing performance is improved.

In the sectional shape obtained by cutting the blade plate 2 on the inner diameter side from the suction diameter Ds with a plane parallel to the rotation axis of the impeller 1, the height h1 of the upper end of the rotation direction surface 2a of the blade plate 2 is h1. Is larger than the height h2 of the upper end of the anti-rotational surface 2b, so that the angle of attack is set at the upper end of the blade 2 on the negative pressure surface side of the blade 2 with respect to the inflow airflow O shown in FIG. That is, the airflow O flowing from the upper end of the slat 2
Is attached to the negative pressure surface of the blade 2 at one end at the upper end of the blade 2,
After that, since the air flows along the blade 2, the separation of the airflow at the upper end of the blade 2 is suppressed.

[0011]

However, in the above configuration, the effect of preventing air flow separation at the upper end portion of the blade plate 2 is generated by the inclined shape of the negative pressure surface at the upper end portion of the blade plate 2. However, if the plate thickness is increased, the air flow passage area inside the impeller 1 decreases, and the air blowing performance of the impeller 1 is deteriorated. The airflow adhesion effect of the present embodiment only has a limited effect on the inflow airflow under the specific operating point condition of low static pressure, and the inflow airflow from the upper end of the blade 2 at the normal high static pressure operating point. Is the suction surface 2 at the upper end of the blade 2
It does not adhere to b and peels off, causing a decrease in air blowing performance and an increase in turbulent noise.

Furthermore, the direction of the airflow flowing into the impeller 1 changes from an axial flow at the suction port of the side plate 4 to a radial flow when flowing between the blade plates 2.
The closer to the side plate 4, the greater the curvature of the airflow and the lower the flow velocity. However, since the cross-sectional shape of the blade 2 near the main plate 3 is the same as the cross-sectional shape of the blade 2 near the side plate 4,
The action of the blades on the airflow is equivalent.

Therefore, near the side plate 4, since the speed of the airflow flowing into the blade plate 2 is low, the airflow speed at the outlet of the blade plate 2 is also low. As shown in FIG. In addition, the flow velocity on the side plate 4 side is significantly lower than the flow velocity on the main plate 3 side. This tendency becomes more remarkable as the axial length of the impeller 1 is increased. Therefore, the amount of heat exchange of the heat exchanger 6 is reduced, and the blowing performance and the blowing efficiency of the centrifugal blower are reduced. There is a problem of causing separation and turbulence of the airflow of the turbulence and increasing turbulence noise.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention has been made in consideration of the above circumstances, and even when a centrifugal blower of an air conditioner is used under high static pressure conditions, the airflow flowing in from the upper end of the blade plate separates on the blade plate negative pressure surface and the airflow is turbulent. By increasing the airflow velocity on the side plate side to make the airflow velocity distribution at the impeller outlet uniform, thereby improving the ventilation performance and reducing turbulent noise. An object of the present invention is to provide an air conditioner capable of preventing a heat exchange amount of a heat exchanger from decreasing.

[0015]

In order to solve this problem, an air conditioner according to the present invention comprises a plurality of blades, a main plate to which the blades are fixed, and an end face of the blades opposite to the main plate. An impeller of a centrifugal blower formed by a side plate having a suction port, a suction ring inserted into the suction port of the side plate, a substantially annular heat exchanger disposed on an outlet side of the impeller, and the blade. In an air conditioner constituted by a casing in which a car, the suction ring, and the heat exchanger are housed, a front edge of an upper portion of a blade plate is extended from a front edge position of a blade in other portions, and The projection has a configuration in which the shape of the projection is substantially triangular.

With this configuration, even when the centrifugal blower of the air conditioner is used under the condition of high static pressure, the inflow airflow is divided into two at the substantially triangular protrusion at the upper end of the blade, and the airflow is divided into two. When each air flow wraps around and flows to the blade negative pressure surface side, by suppressing the separation of the blade negative pressure surface, the inflow airflow from the upper end of the blade plate is reduced without increasing the thickness of the blade plate. It is configured to adhere to the negative pressure surface and flow along the blade plate.

[0017] Thus, even when used under high static pressure conditions, the inflow airflow from the upper end of the blade can be reliably adhered to the blade negative pressure surface, thereby suppressing a reduction in air blowing performance and an increase in turbulent noise. Further, it is possible to prevent the heat exchange amount of the heat exchanger from being reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 comprises a plurality of blades, a main plate to which the blades are fixed, and a side plate having a suction port fixed to an end face of the blades on the side opposite to the main plate. A centrifugal blower, a suction ring inserted into a suction port of the side plate, a substantially annular heat exchanger disposed on an outlet side of the impeller, and the heat exchange between the impeller and the suction ring. In the air conditioner constituted by a casing in which the inside of the impeller is housed, the front edge of the upper part of the blade plate is extended from the front edge position of the blades of the other parts, and protrudes toward the inner diameter side of the impeller, and The air conditioner has a substantially triangular shape, and the inflow airflow is divided into two at the substantially triangular protrusion at the upper end of the blade, and the respective airflows wrap around the protrusion to the blade negative pressure side. When flowing in, acts to suppress the separation of the blade negative pressure surface Therefore, even when the centrifugal blower of the air conditioner operates under high static pressure conditions, the inflow airflow from the upper end of the blade plate adheres to the blade negative pressure surface and flows along the blade plate. Therefore, the inflow airflow from the upper end portion of the blade is made to adhere to the blade negative pressure surface, so that it is possible to suppress a decrease in the blowing performance and an increase in turbulent noise.

According to a second aspect of the present invention, in the blade section perpendicular to the rotation axis of the impeller, the blade exit angle of the blade section in the vicinity of the side plate is further calculated from the blade exit angle of the blade section in the vicinity of the main plate. It is an air conditioner in which the blade cross section from the main plate to the side plate is continuously changed, and the centrifugal blower of the air conditioner operates under a high static pressure condition, even if the centrifugal blower is operated under a high static pressure condition. By admitting the inflow airflow to the negative pressure surface of the blade, it is possible to suppress the deterioration of the blowing performance and the increase of turbulent noise, and furthermore, the blade outlet angle of the blade section near the side plate is made larger than the blade outlet angle of the blade section near the main plate. By increasing the work volume of the blades on the side plate side from the work volume of the blades on the main plate side, the flow velocity on the side plate side is increased and the airflow velocity distribution at the impeller outlet is made uniform. Therefore, it is possible to improve the air blowing performance on the side plate side, prevent a decrease in the heat exchange amount of the heat exchanger, and prevent a decrease in the air conditioning performance.

According to a third aspect of the present invention, in addition to the first aspect of the present invention, the position of the connecting end between the side plate and the blade at the trailing edge of the blade is changed to the connecting end between the main plate and the blade. An air conditioner in which the rear edge of the blade plate from the main plate to the side plate is continuously changed by setting the position in the direction opposite to the rotation direction from the position of the part, and the inflow airflow from the upper end of the blade To the blade negative pressure surface, it is possible to suppress a decrease in ventilation performance and an increase in turbulent noise, and further, at a trailing edge portion of the blade plate, a position of a coupling end portion between the side plate and the blade plate is changed to a position between the main plate and the main plate. By setting the position opposite to the rotation direction from the position of the connection end with the blade, the action of the force acting on the airflow passing through the blade is only the component in the plane perpendicular to the rotation axis There is also a component that goes from the main plate side to the side plate side. Ri, will equalize the air velocity distribution at the impeller outlet is accelerated the flow rate of the side plate.
Therefore, by improving the blowing performance and preventing the heat exchange amount of the heat exchanger from decreasing, it is possible to prevent the air conditioning performance from decreasing. Furthermore, turbulence noise can be further reduced by suppressing separation and turbulence of the airflow near the side plate.

According to a fourth aspect of the present invention, in addition to the third aspect of the present invention, the shape of the blade of the centrifugal blower is substantially the same in the rotational direction position of the trailing edge of the blade at a predetermined height from the main plate. The air conditioner is a harmony machine, in which the inflow airflow from the upper end of the blade is attached to the blade negative pressure surface, which can suppress a decrease in the blowing performance and an increase in turbulent noise, and furthermore, at the trailing edge of the blade, the side plate and the blade By setting the position of the coupling end with the plate at a position opposite to the direction of rotation from the position of the coupling end with the main plate and the blade, the action of the force acting on the airflow passing through the blade is Because not only components in the plane perpendicular to the rotation axis but also components from the main plate side to the side plate side are generated, the airflow is deviated to the side plate side, the flow velocity on the side plate side is increased, and the airflow velocity distribution at the impeller outlet is uniform. Will be transformed. Therefore, by improving the blowing performance and preventing the heat exchange amount of the heat exchanger from decreasing, it is possible to prevent the air conditioning performance from decreasing. Furthermore, turbulence noise can be further reduced by suppressing separation and turbulence of the airflow near the side plate. Furthermore, by making the rotation direction position of the trailing edge portion of the blade plate substantially the same at a predetermined height from the main plate,
Prevents airflow of low flow velocity from concentrating on the negative pressure surface side of the trailing edge of the blade near the main plate, forming a stable airflow distribution near the main plate, and stable even if the operating point of the centrifugal blower changes Blow performance can be maintained.

Moreover, the blade plate and the main plate are molded integrally with resin,
When manufacturing by welding the blades to the resin side plate by ultrasonic vibration, the vibration when the main plate is vibrated by the vibrator is effectively transmitted to the side plate side through the vertical part of the blade plate. Thus, reliable welding can be performed, and productivity and rotational strength can be improved.

[0023]

(Embodiment 1) FIG. 1 shows a structure of an air conditioner according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of an impeller of a centrifugal blower mounted on the air conditioner in Embodiment 1 of FIG. FIG. 3 shows the structure of the impeller of the centrifugal blower according to the first embodiment shown in FIG.

In the figure, reference numeral 10 denotes an impeller of a centrifugal blower, and a plurality of blade plates 11 and a main plate 1 to which the blade plates 11 are fixed.
2 and a side plate 13 having a suction port fixed to the end surface of the blade plate 11 on the side opposite to the main plate. Reference numeral 5 denotes an electric motor directly connected to the impeller 10, and reference numeral 6 denotes a substantially annular heat exchanger disposed on the outlet side of the impeller 10, which is housed and fixed together with the impeller 10 in a casing 7. Reference numeral 8 denotes a suction ring fixed to the casing. The suction ring 8 is curved from an inlet end 8a to an outlet end 8b, and has an outlet end 8b.
b is inserted into the side plate 13 of the impeller 10.

The suction diameter Ds of the side plate 11 is set to be larger than the blade entrance diameter D1.
The leading edge of the upper portion of the first member 1 is extended from the leading edge position of the other portion of the blade, is projected toward the inner diameter side of the impeller, and the shape of the projection 11a is substantially triangular. The tip 11b of the substantially triangular projection 11a is connected to the rear edge of the blade 11 and the side plate 13a.
DD cross section parallel to the main plate 12 and the side plate 13
Is set between the suction ports 13a.

The operation of the centrifugal blower constructed as described above will be described below. First, when the impeller 10 rotates in a predetermined rotation direction by the driving force of the electric motor 5, air flows into the impeller 10 via the suction ring 8, and a static pressure is generated when passing between the plurality of blade plates 11. Further, it is heated or cooled when passing through the heat exchanger 6, and is blown out from the blow-out port 9 to adjust the room temperature and the room humidity.

Further, by making the suction diameter Ds of the side plate 13 larger than the blade inlet diameter D1 of the blade plate 11, the inflow air flows from the upper end of the blade. Lower, impeller 1
The inflow resistance to zero and the flow resistance (loss) inside the impeller 10 are reduced, and the air volume is increased at the operating point with low pressure, so that the blowing performance can be improved.

Here, since the upper end of the blade plate 11 is formed as a substantially triangular protrusion 11a, the airflow P flowing from the upper end of the blade plate 11 is changed to the protrusion 11a as shown in FIG.
When the respective airflows wrap around the protrusion 11a and flow toward the blade negative pressure surface side, the separation of the blade negative pressure surface is suppressed, so that the thickness of the blade plate 11 is not increased. Then, the inflow airflow from the upper end of the blade plate adheres to the blade negative pressure surface and flows along the blade plate 11.

Thus, even when the centrifugal blower of the air conditioner is used under the condition of high static pressure, the inflow airflow from the upper end of the blade is surely adhered to the blade negative pressure surface, and the blade negative pressure surface of the blade plate 11 is used. Suppress the separation of the airflow.

Therefore, even when the impeller 10 is used under a condition of higher static pressure than the design operating point, the inflow airflow P from the upper end of the blade plate 11 adheres to the blade negative pressure surface and follows the blade plate 11. Flows. Therefore, the inflow airflow from the upper end portion of the blade plate 11 is made to adhere to the blade negative pressure surface, so that a decrease in the blowing performance and an increase in turbulent noise can be suppressed.

As described above, according to the present embodiment, the blade 1
1 is formed in a substantially triangular projection 11a, so that the airflow flowing from the upper end of the slat 11 is
1a, the airflow diverges around the protrusion 11a, and the respective airflows flow around and flow toward the blade negative pressure surface side. Therefore, separation of the airflow on the blade negative pressure surface can be suppressed, and the impeller 10
Can be suppressed at a high static pressure operating point, and a reduction in the blowing capacity can be suppressed, and an increase in turbulent noise due to flow separation can be suppressed.

In this embodiment, the upper end portion of the blade plate 11 is formed in a vertical shape with respect to the main plate 12.
As shown in FIG. 4 showing an E-section, the upper end of the blade 11 is inclined in the rotation direction of the impeller 10 so that the blade plate 10
Can effectively guide the inflow airflow P from the upper end of the blade to the blade negative pressure surface, further enhance the effect of preventing airflow separation on the blade negative pressure surface, and suppress turbulent noise.

Embodiment 2 FIG. 5 shows the structure of an impeller of a centrifugal blower mounted on an air conditioner in Embodiment 2 of the present invention, and FIG. 6 shows the structure of the impeller of the centrifugal blower in Embodiment 2 of FIG. FIGS. 7 and 8 are perspective views, and FIGS. 7 and 8 are sectional views taken along line EE of the impeller of the centrifugal blower according to the second embodiment shown in FIG.
It shows a cross section.

In the drawing, in addition to the air conditioner according to the first embodiment of the present invention, in the cross section of the blade plate 15 orthogonal to the rotation axis of the impeller 14, the blade exit angle βs in the cross section of the blade near the side plate 16 is changed to the blade near the main plate 17. The blade exit angle βh of the cross section is set to be larger, and the blade cross section from the main plate 17 to the side plate 16 is continuously changed.

The operation of the air conditioner configured as described above will be described below. First, when the impeller 14 rotates in a predetermined rotation direction by the driving force of the electric motor 5, air flows into the impeller 14 via the suction ring 8 and generates static pressure when passing between the plurality of blades 15. Further, it is heated or cooled when passing through the heat exchanger 6, and is blown out from the blow-out port 9 to adjust the room temperature and the room humidity.

Here, in the blade section orthogonal to the rotation axis of the impeller 14, the blade exit angle β of the blade section near the side plate 16
Since s is set to be larger than the blade exit angle βh of the blade section near the main plate 17 and the blade cross-sectional shape from the main plate 17 to the side plate 16 is continuously changed, the reduction in the work amount of the blade plate 15 on the side plate 16 side is reduced. Thus, the flow velocity on the side plate 15 side is increased, and the airflow velocity distribution at the outlet of the impeller 14 is made uniform. Therefore, it is possible to improve the air blowing performance and prevent the heat exchange amount of the heat exchanger 6 from being reduced.

When the impeller 14 of the centrifugal blower is used under conditions of higher static pressure than the design operating point, the blade exit angle βs of the blade section near the side plate 16 is set to be large,
Separation of airflow is likely to occur on the blade negative pressure surface on the side plate 16 side, and turbulence of airflow tends to increase. However, since the upper end of the blade plate 15 is formed in a substantially triangular projection 15a, the blade The airflow flowing from the upper end of the plate 15 is
a, and when the respective airflows flow around the protrusions 15a and flow toward the blade negative pressure surface side, by suppressing the separation of the blade negative pressure surface, the generation of turbulent noise due to the airflow separation is suppressed. The effect is obtained.

Therefore, even when the impeller 14 is used under conditions of higher static pressure than the design operating point, the inflow airflow from the upper end of the blade plate 15 adheres to the blade negative pressure surface and flows along the blade plate 15. Then, the inflow airflow from the upper end of the blade plate 15 is adhered to the blade negative pressure surface, and the work volume of the blade plate 15 on the side plate 16 side is increased from the blade work volume on the main plate 17 side to increase the flow velocity on the side plate 15 side. And the airflow velocity distribution at the outlet of the impeller 14 can be made uniform. Therefore, it is possible to improve the air blowing performance, reduce the turbulent noise by suppressing the separation and turbulence of the air flow near the side plate 16, and further prevent the heat exchange amount of the heat exchanger 6 from decreasing.

As described above, according to the present embodiment, the impeller 1
4, the blade outlet angle βs of the blade cross section near the side plate 16 is set to be larger than the blade outlet angle βh of the blade cross section near the main plate 17,
By continuously changing the blade cross-sectional shape up to
By increasing the work amount of the blade plate 15 on the side plate 16 side than the work amount of the blade plate on the main plate 17 side, the air flow velocity distribution at the outlet of the impeller 14 can be made uniform, so that the blowing performance is improved. Is used under a higher static pressure condition than the design operating point, the inflow airflow from the upper end of the blade plate 15 adheres to the blade negative pressure surface by the action of the projection 15a, and the side plate 1
By suppressing separation and turbulence of the airflow near the turbulence 6, turbulent noise can be reduced, and furthermore, the amount of heat exchange of the heat exchanger 6 can be prevented from being reduced.

In this embodiment, the upper end of the blade plate 15 is formed vertically with respect to the main plate 17, but by tilting the upper end of the blade 15 in the rotation direction of the impeller 14,
The inflow airflow from the upper end of the blade plate 15 can be effectively guided to the blade negative pressure surface, the effect of preventing airflow separation on the blade negative pressure surface can be enhanced, and the turbulent noise can be suppressed low.

(Embodiment 3) FIG. 9 shows the structure of an impeller of a centrifugal blower mounted on an air conditioner in Embodiment 3 of the present invention, and FIG. 10 shows the structure of the impeller of the centrifugal blower in Embodiment 3 of FIG. FIG. 11 is a perspective view, and FIG. 11 is a partial front view of the impeller of the centrifugal blower according to the third embodiment in FIG.

In the drawing, the position of the connecting end 18 s between the side plate 19 and the blade 18 at the rear edge of the impeller 18 is further changed from the air conditioner according to the first embodiment of the present invention to the main plate 2.
A position opposite to the rotation direction is set to a position opposite to the rotation direction from the position of the coupling end 18 h between the zero and the blade 18, and the rear edge of the blade 18 from the main plate 20 to the side plate 19 is continuously changed.

The operation of the air conditioner configured as described above will be described below. First, when the impeller 21 rotates in a predetermined rotation direction by the driving force of the electric motor 5, air flows into the impeller 21 through the suction ring 8, and when passing between the plurality of impellers 18, static pressure is applied. Further, it is heated or cooled when passing through the heat exchanger 6, and is blown out from the blow-out port 9 to adjust the room temperature and the room humidity.

Here, at the rear edge of the blade plate 18, the position of the connecting end 18s between the side plate 19 and the blade plate 18 is determined by the main plate 2
Since the rotation direction is set to a position opposite to the direction of rotation from the position of the coupling end 18h between the zero and the blade 18 and the rear edge of the blade 18 from the main plate 20 to the side plate 19 is continuously changed. The action of the force acting on the airflow passing through the plate 18 includes not only a component in a plane perpendicular to the rotation axis but also a component directed from the main plate 20 side to the side plate 19 side. The flow velocity on the 19th side is increased, and the airflow velocity distribution at the exit of the impeller 21 is made uniform. for that reason,
It is possible to improve the blowing performance and prevent the heat exchange amount of the heat exchanger 6 from being reduced.

When the impeller 21 of the centrifugal blower is used under a condition of higher static pressure than the design operating point, the connecting edge 18 between the side plate 19 and the blade plate 18 is provided at the rear edge of the blade plate 18.
When the position of s is set to a position opposite to the rotation direction from the position of the coupling end 18h of the main plate 20 and the blade plate 18, airflow separation easily occurs on the blade negative pressure surface on the side plate 19 side,
Although the turbulence of the airflow tends to increase, the upper end of the blade plate 18 is formed in the substantially triangular protrusion 18a, so that the airflow flowing from the upper end of the blade plate 18 is divided into two by the protrusion 18a. When the respective airflows wrap around the projection 18a and flow toward the blade negative pressure surface side, by suppressing the separation of the blade negative pressure surface, an effect of suppressing the generation of turbulent noise due to the airflow separation can be obtained.

Therefore, even when the impeller 21 is used under a condition of higher static pressure than the design operating point, the inflow airflow from the upper end of the blade plate 18 adheres to the blade negative pressure surface 18a and the blade plate 18
Flows along the upper surface of the blade plate 18 and adheres to the blade negative pressure surface 18a. Further, the action of the force acting on the air flow passing through the blade plate 18 is changed from the main plate 20 side to the side plate 19 side. Since an airflow component also occurs, the airflow is deviated to the side plate 19 side to increase the flow velocity on the side plate 19 side, and the airflow velocity distribution at the exit of the impeller 21 is made uniform. for that reason,
By improving the air blowing performance and suppressing the separation and turbulence of the airflow near the side plate 19, the turbulent noise can be reduced, and the heat exchange amount of the heat exchanger 6 can be prevented from lowering.

As described above, according to the present embodiment, the blade 1
8, the position of the connection end 18 s between the side plate 19 and the wing plate 18 is changed to the connection end 1 between the main plate 20 and the wing plate 18.
8h is set at a position opposite to the rotation direction from the position of rotation, and the trailing edge of the blade plate 18 from the main plate 20 to the side plate 19 is continuously changed so that the impeller 21 can be used under high static pressure conditions. Even in this case, the inflow airflow from the upper end of the blade plate 18 adheres to the blade negative pressure surface 18a, and the action of the force acting on the airflow passing through the blade plate 18 goes from the main plate 20 side to the side plate 19 side. Since the components also occur, the airflow velocity distribution at the exit of the impeller 21 is made uniform. Therefore, it is possible to improve the air blowing performance, reduce the turbulence noise by suppressing the separation and turbulence of the air flow near the side plate 19, and further prevent the heat exchange amount of the heat exchanger 6 from decreasing.

Fourth Embodiment FIG. 12 is a perspective view of an impeller of a centrifugal blower mounted on an air conditioner according to a fourth embodiment of the present invention.

In FIG. 12, in addition to the structure of the first embodiment, the position of the connection end 22s between the side plate 23 and the blade 22 at the rear edge of the blade 22 is changed to the connection end between the main plate 24 and the blade 22. The rotation direction is set to a position opposite to the rotation direction from the position of 22h. The difference from the third embodiment is that the rotation position of the rear edge portion of the blade plate 22 is substantially the same from the main plate 24 to a predetermined height h0. And from the height h0 to the side plate 23, the blade plate 22
Is that the trailing edge is continuously changed.

The operation of the air conditioner configured as described above will be described below. First, when the impeller 25 rotates in a predetermined rotation direction by the driving force of the electric motor 5, air flows into the impeller 21 via the suction ring 8, and when passing between the plurality of blade plates 18, the static pressure is generated. Further, it is heated or cooled when passing through the heat exchanger 6, and is blown out from the blow-out port 9 to adjust the room temperature and the room humidity.

Here, as in the third embodiment, the side plate 23 is simply formed.
When the trailing edge of the blade plate 22 is continuously changed up to that, the discharge airflow velocity at the trailing edge of the blade plate 22 is changed from the main plate 24 to the side plate 2.
3, the airflow at a low flow velocity tends to concentrate on the negative pressure surface side of the trailing edge of the blade near the main plate 24. In particular, the operating point of the centrifugal blower has a high static pressure. Although the blowing performance may be reduced under the operating point condition, the rotation of the main plate 2 from the main plate 24 to the predetermined height h0 is substantially the same at the rear edge of the blade plate 22 in the rotational direction.
Since the flow velocity distribution at the trailing edge of the blade near 4 is not displaced in the rotational direction, the airflow of the low flow velocity is prevented from concentrating on the suction surface side of the trailing edge of the blade near the main plate 24, A stable air flow distribution can be formed, and a stable air blowing performance can be maintained even if the operating point of the centrifugal blower changes.

Further, a predetermined height h0 from the main plate 24 is set.
Up to this point, the rotation direction position of the rear edge portion of the blade plate 22 is made substantially the same, so that the blade plate 22 and the main plate 24 are integrally molded with resin, and the blade plate 22 is welded to the resin side plate by ultrasonic vibration. In the case of manufacturing, the vibration when the main plate 24 is vibrated by the vibrator can be effectively transmitted to the side plate 22 side through the vertical portion of the blade plate 22, and reliable welding can be performed.

As described above, according to the present embodiment, the blade 2
2, the position of the joint end 22 s between the side plate 23 and the blade plate 22 is changed to the joint end 2 between the main plate 24 and the blade plate 22.
2h, the rotation direction is set to a position opposite to the rotation direction. Further, from the main plate 24 to a predetermined height h0, the rotation direction position of the rear edge of the blade plate 22 is made substantially the same.
3, the trailing edge of the blade plate 22 is continuously changed, so that even when the impeller 25 is used under high static pressure conditions, the inflow airflow from the upper end of the blade plate 22 causes the blade negative pressure surface 2
2a, the component of the force acting on the airflow passing through the impeller plate 22 also has a component directed from the main plate 24 side to the side plate 23 side, so that the airflow velocity distribution at the exit of the impeller 25 is made uniform. Become. Therefore, the air blowing performance is improved, the turbulence noise is reduced by suppressing the separation and turbulence of the airflow near the side plate 23, and the heat exchange amount of the heat exchanger 6 can be prevented from lowering. Moreover, the main plate 2
4 prevents the airflow of low flow velocity from concentrating on the negative pressure surface side of the trailing edge of the blade in the vicinity, and can form a stable airflow distribution near the main plate, and is stable even when the operating point of the centrifugal blower changes. Blow performance can be maintained.

Furthermore, when the blade plate 22 and the main plate 24 are integrally molded with resin and the blade plate 22 is welded to the resin side plate by ultrasonic vibration, the main plate 24 is vibrated by a vibrator. The vibration of the side plate 2 is effectively transmitted through the vertical portion of the blade plate 22.
It can be transmitted to the two sides, reliable welding can be performed, and productivity and rotational strength can be improved.

In the first, second, third, and fourth embodiments, the vertical blade cross section of the impeller of the centrifugal blower has a substantially flat plate shape. By adopting the mold shape, the air blowing performance can be further improved, and the turbulent noise can be further reduced.

In the second, third, and fourth embodiments, the upper end of the blade plate is vertically formed with respect to the main plate.
As shown in FIG. 4 of the first embodiment, the vertical cross section of the blade is inclined at the upper end of the blade in the rotation direction of the impeller, thereby effectively guiding the inflow airflow from the upper end of the blade to the negative pressure surface of the blade. In addition, the effect of preventing airflow separation on the blade negative pressure surface can be enhanced, and turbulent noise can be suppressed low.

[0057]

As described above, the invention according to claim 1 is
A plurality of blade plates, a main plate to which the blade plates are fixed, and an impeller of a centrifugal blower formed by a side plate having a suction port fixed to an end surface on the side opposite to the main plate of the blade plates, and a suction port of the side plate. An air conditioner comprising an inserted suction ring, a substantially annular heat exchanger disposed on the outlet side of the impeller, and a casing containing the impeller, the suction ring, and the heat exchanger inside. In the above, the front edge of the upper part of the blade plate is extended from the front edge position of the blades of the other parts, and protrudes toward the inner diameter side of the impeller, and the shape of the protrusion is substantially triangular. In order to deflect the inflow air flow and guide the air flow to the blade negative pressure surface, and to further guide the stable air flow to the blade negative pressure surface in the substantially vertical portion of the downstream blade plate, the separation of the air flow at the blade negative pressure surface is suppressed. Operating the impeller at a high static pressure operating point. It suppresses a reduction in blowing capacity even if it is possible to suppress an increase in turbulence noise caused by flow separation.

The invention described in claim 2 is the same as the claim 1.
Further, in the blade section orthogonal to the rotation axis of the impeller, the blade exit angle of the blade section near the side plate is set to be larger than the blade exit angle of the blade section near the main plate, and the blade section from the main plate to the side plate. Since the shape is continuously changed, the work volume of the blades on the side plate side should be increased from the work volume of the blades on the main plate side to increase the flow velocity on the side plate side and make the airflow velocity distribution at the exit of the impeller uniform. Therefore, the air blowing performance is improved, the turbulence noise is reduced by suppressing the separation and turbulence of the air flow near the side plate, and the heat exchange amount of the heat exchanger is prevented from decreasing, and the air conditioning performance is reduced. Can be prevented from decreasing.

Further, the invention described in claim 3 is the first invention.
Further, from the invention described in the above, at the trailing edge of the blade plate, the position of the coupling end between the side plate and the blade plate is in a position opposite to the rotational direction from the position of the coupling end between the main plate and the blade plate. Setting, since the trailing edge of the blade plate from the main plate to the side plate is continuously changed, the airflow is biased to the side plate side,
Since the flow velocity on the side plate side is increased and the air flow velocity distribution at the impeller outlet is made uniform, the air blowing performance is improved, and the turbulence noise is reduced by suppressing the separation and turbulence of the air flow near the side plate, Further, it is possible to prevent the heat exchange amount of the heat exchanger from being reduced, and to prevent the air conditioning performance from being lowered.

The invention described in claim 4 is the first invention.
Further, from the invention described in the above, at the trailing edge of the blade plate, the position of the coupling end between the side plate and the blade plate is in a position opposite to the rotational direction from the position of the coupling end between the main plate and the blade plate. Since the rotation position of the trailing edge of the blade plate at the predetermined height from the main plate is substantially the same, and the trailing edge of the blade plate is continuously changed from the predetermined height to the side plate, Skewed to the side plate side, increasing the flow velocity on the side plate side and uniforming the airflow velocity distribution at the impeller outlet, thus improving the air blowing performance and suppressing turbulence by suppressing air flow separation and turbulence near the side plate. It is possible to reduce the flow noise, prevent the heat exchange amount of the heat exchanger from decreasing, and prevent the air conditioning performance from decreasing. Moreover, it is possible to prevent the airflow of low flow velocity from being concentrated on the negative pressure surface side of the trailing edge of the blade near the main plate, to form a stable airflow distribution near the main plate, and to change the operating point of the centrifugal blower. Stable ventilation performance can be maintained.

Furthermore, when the blade plate and the main plate are integrally formed of resin and the blade plate is welded to the resin side plate by ultrasonic vibration, the vibration when the main plate is vibrated by the vibrator is caused by the vibration of the blade. Power can be effectively transmitted to the side plate through the vertical portion of the plate, reliable welding can be performed, and productivity can be improved and rotational strength can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an impeller of a centrifugal blower mounted on the air conditioner according to the first embodiment of the present invention.

FIG. 3 is a detailed view of a main part of an impeller of a centrifugal blower mounted on the air conditioner according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part of the impeller of the centrifugal blower mounted on the air conditioner according to the first embodiment of the present invention along line EE.

FIG. 5 is a detailed view of a main part of an impeller of a centrifugal blower mounted on an air conditioner according to a second embodiment of the present invention.

FIG. 6 is a perspective view of an impeller of a centrifugal blower mounted on an air conditioner according to Embodiment 2 of the present invention.

FIG. 7 is a cross-sectional view of a main part of an impeller of a centrifugal blower mounted on an air conditioner according to a second embodiment of the present invention, taken along line FF.

FIG. 8 is a cross-sectional view of a main part of a centrifugal blower mounted on the air conditioner according to a second embodiment of the present invention, taken along line GG.

FIG. 9 is a detailed view of a main part of an impeller of a centrifugal blower mounted on an air conditioner according to a third embodiment of the present invention.

FIG. 10 is a perspective view of an impeller of a centrifugal blower mounted on an air conditioner according to Embodiment 3 of the present invention.

FIG. 11 is a partial front view of an impeller of a centrifugal blower mounted on an air conditioner according to Embodiment 3 of the present invention.

FIG. 12 is a perspective view of an impeller of a centrifugal blower mounted on an air conditioner according to Embodiment 4 of the present invention.

FIG. 13 is a sectional view of a conventional air conditioner.

FIG. 14 is a detailed view of a main part of an impeller of a centrifugal blower mounted on a conventional air conditioner.

FIG. 15 is a cross-sectional view of a main part taken along line AA of an impeller of a centrifugal blower mounted on a conventional air conditioner.

FIG. 16 is a schematic diagram showing an airflow velocity distribution at an impeller outlet of a centrifugal blower mounted on a conventional air conditioner.

[Explanation of symbols]

10, 14, 21, 25 Impeller 11, 15, 18, 22 Impeller 11a, 15a, 18a, 22a Protrusion of impeller 12, 17, 20, 24 Main plate 13, 16, 19, 23 Side plate 18h Main plate side connection End 18s Side plate side combined end β _h Main plate side blade exit angle β _s side plate side blade exit angle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Tatsui 4-5-2-5 Takaidahondori, Higashiosaka-shi, Osaka Matsushita Refrigerator Co., Ltd. F-term (reference) 3L049 BB07 BC03 BD01

Claims (4)

[Claims] An impeller of a centrifugal blower formed of a plurality of blades, a main plate to which the blades are fixed, and a side plate having a suction port fixed to an end surface of the blades on a side opposite to the main plate, and A suction ring inserted into the suction port, a substantially annular heat exchanger disposed on the outlet side of the impeller, and a casing containing the impeller, the suction ring, and the heat exchanger therein. In the air conditioner, the front edge of the upper portion of the blade plate is extended from the front edge position of the other portion of the blade, protrudes toward the inner diameter side of the impeller, and the shape of the protrusion is substantially triangular. 2. The air conditioner according to claim 1, wherein a blade exit angle of the blade section near the side plate is set to be larger than a blade exit angle of the blade section near the main plate in a blade section orthogonal to a rotation axis of the impeller. 3. A rear edge portion of the blade plate, wherein a position of a joint end between the side plate and the blade plate is set to a position opposite to a rotational direction from a position of a joint end between the main plate and the blade plate. The air conditioner according to claim 1, wherein a trailing edge of the blade from the main plate to the side plate is continuously changed. 4. A rear edge portion of the blade plate, wherein a position of a connection end between the side plate and the blade plate is set to a position opposite to a rotational direction from a position of a connection end portion of the main plate and the blade plate. 2. The air conditioner according to claim 1, wherein, in a blade cross section orthogonal to a rotation axis of the impeller, a position in a rotation direction of a rear edge of the blade plate is substantially the same at a predetermined height from the main plate.