JP2007291902A - Diagonal flow blower impeller and air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low noise diagonal flow blower impeller excellent in fan efficiency. <P>SOLUTION: A leading edge 2 of an aerofoil 6 is formed by a concave curve to an upwind side in an outer circumference side of a section near a center point of a hub 4 and a tip 5 of the aerofoil 6 and by a convex curve in a hub 4 side of the section near the center point at a meridional plane. A section shape in a radial direction of the aerofoil 6 is formed by a concave curve to an upwind side in an outer circumference side of the section near the center point and by a convex curve in the hub 4 side of the section near the center point. A vertical hub 4b starting from a section near the minimum radius of a cone hub 4a and directly connecting in a direction roughly vertical to a pressure surface side of the aerofoil 6 is provided between the cone hub 4a directly connecting to a negative pressure surface side of the aerofoil 6, the cone hub 4a and the vertical hub 4b are continuously connected without a lacking part and a part in a downwind side of the vertical hub 4b is cut out with leaving a margin at step parts of the aerofoil 6, the cone hub 4a and the vertical hub 4b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mixed flow blower impeller used for an outdoor unit of an air conditioner and the like and an air conditioner using the same.

  A conventional mixed flow fan impeller of this type will be described with reference to FIGS.

11 to 13, a conventional mixed-flow fan impeller 30 is configured by providing a plurality of thin blades 35 on a substantially frustoconical hub 33, and a leading edge 31 of the blade 35 is connected to a meridian of the blade 35. On the surface, the curved surface is concave with respect to the windward side near the midpoint between the hub 33 and the tip 34 of the blade 35, and is convex with respect to the windward side near the midpoint on the hub 33 side. And the radial cross-sectional shape of the blades 35 is a concave curve with respect to the windward side from the vicinity of the midpoint, and the hub 33 side is convex with respect to the windward side from the midpoint. It is formed so as to have a curved shape, and is connected between the conical hub 33a directly connected to the suction surface side of the blade 35 and directly connected in the substantially vertical direction to the pressure surface side of the blade 35, starting from the vicinity of the minimum radius of the cone hub 33a. Vertical hub 33b is provided, conical hub 33a and vertical hub 33b The by connecting continuously, and is configured so as there is no missing portion of these hub 33 (e.g., see Patent Document 1).
Japanese Patent No. 2877536

  However, in the configuration of the conventional mixed flow blower impeller 30 described above, the generation of the blade tip vortex generated on the suction surface near the outer peripheral side of the blade 35 is generated by the leakage flow from the pressure surface of the blade 35 toward the suction surface. Noise can be reduced by promoting the concave curved portion. In addition, the convex curved portion of the wing 35 on the hub 33 side can smoothly flow in the radial direction in the high load region and simultaneously improve the static pressure. However, between the conical hub 33a directly connected to the suction surface side of the blade 35, there is provided a vertical hub 33b starting from the vicinity of the minimum radius of the conical hub 33a and directly connected to the pressure surface side of the blade 35 in a substantially vertical direction. Even if the hub 33a and the vertical hub 33b are continuously connected so that these hubs 33 have no missing portions, the vertical hub 33b gives a centrifugal component to the flow, so that the static pressure characteristics of the mixed flow fan impeller 30 can be obtained. Can be improved. However, when the flowing air flow is about to pass through the hub 33, the pressure inside the hub 33 is low, there is a flow that tries to go inside, and the vertical hub 33b serves to block the flow. . For this reason, the air flow state of the mixed flow blower impeller 30 cannot be optimized, and there are clear limits to noise reduction and fan efficiency improvement.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a mixed flow blower impeller with low noise and excellent fan efficiency.

In order to solve the above-mentioned conventional problems, the mixed flow fan impeller of the present invention is a mixed flow fan impeller in which a plurality of thin blades are provided on a substantially truncated cone-shaped hub. On the meridional surface of the wing, a curved curve that is concave with respect to the windward side from the vicinity of the midpoint between the hub and the tip of the wing, and from the vicinity of the midpoint to the windward side on the hub side. It is formed so as to have a convex curve, and the radial cross-sectional shape of the blade is a curved curve that is concave with respect to the windward side on the outer peripheral side from the vicinity of the midpoint, and the hub side is on the windward side from the vicinity of the midpoint. Between the conical hub directly connected to the suction surface side of the blade and the vertical direction from the pressure surface side of the blade. A vertical hub that is directly connected to the conical hub and the vertical hub. The conical and vertical hubs are constructed so that there are no missing parts, and the leeward side of the vertical hub is left with a margin for the stepped parts of the wings, the conical hub and the vertical hub. The generation of the blade tip vortex generated on the suction surface near the outer periphery of the blade is promoted by the concave curved portion of the blade due to the leakage flow from the blade pressure surface to the suction surface. In addition, it is the same for the smooth curved inflow in the high load region at the convex curved portion of the wing on the hub side. In addition, since the leeward part of the vertical hub is cut off, when the air flow is about to pass through the mixed flow fan impeller, the pressure inside the hub is low, Demonstrates the action induced by the notch of the vertical hub to optimize the flow state of the mixed flow fan impeller as a whole, and the generation of blade tip vortex generated on the suction surface near the outer periphery of the blade Combined with the effect of promoting the curved portion, the most complete air flow state can be realized in the mixed flow fan impeller, so that noise reduction and fan efficiency can be improved more than before. Further, since the vertical hub is cut out, the material used can be reduced correspondingly, and the cost can be reduced.

  The mixed flow blower impeller of the present invention can reduce noise and improve fan efficiency more than before, and since the vertical hub has a notch, it can reduce the material used and can be constructed at low cost.

  A first aspect of the present invention is a mixed flow fan impeller in which a plurality of thin blades are provided on a substantially frustoconical hub, the front edge of the blade being a meridian surface of the blade, and the hub and the blade. The tip is formed to have a concave curve with respect to the windward side on the outer peripheral side from the vicinity of the midpoint, and to have a convex curve with respect to the windward side on the hub side from near the midpoint. The radial cross-sectional shape is a curve that is concave with respect to the windward side on the outer peripheral side from the vicinity of the midpoint, and the hub side is formed with a convex curve with respect to the windward side from the vicinity of the midpoint, Between the conical hub that is directly connected to the suction surface side of the blade, a vertical hub that starts from the vicinity of the minimum radius of the conical hub and is directly connected to the pressure surface side of the blade in a substantially vertical direction is provided, and the conical hub and the vertical hub are provided. Connecting the hub continuously, these cones, vertical hubs are missing The wing, the conical hub, the stepped portion of the vertical hub, and the leeward side portion of the vertical hub is cut away from the stepped portion of the vertical hub. The generation of blade vortices generated on the suction surface near the outer periphery of the blade is promoted at the concave curved portion of the blade by the leakage flow toward the blade. In addition, it is the same for the smooth curved inflow in the high load region at the convex curved portion of the wing on the hub side. In addition, since the leeward part of the vertical hub is cut off, when the air flow is about to pass through the mixed flow fan impeller, the pressure inside the hub is low, The notch of the vertical hub induces the action to optimize the flow state of the entire mixed flow fan impeller, and the generation of the tip vortex generated on the suction surface near the outer periphery of the blade Combined with the effect of promoting the curved portion, the most complete air flow state can be realized in the mixed flow fan impeller, so that noise reduction and fan efficiency can be improved more than before. Further, since the vertical hub is cut out, the material used can be reduced correspondingly, and the cost can be reduced.

In the second invention, in particular, the number of the wings of the first invention is set to 2, the hub on the leading edge and the radius to the midpoint of the tip are r1 on the meridian surface of the wing, and the hub on the trailing edge And the radius to the midpoint of the tip is r2, and in the cross-sectional developed shape of the blade at the flow path centerline (centerline connecting r1 and r2) connecting the midpoint of each of the leading edge and the trailing edge The chord length is L, the radial length of the blade on the radius of R = (r1 + r2) / 2 is b, the aspect ratio is b / L ≦ 1.1, and the number of blades is two. Therefore, since the number of blades is the smallest, the blade area input is the smallest, and the fluid friction is small, the fluid friction per aerodynamic work is small, so that the fan efficiency is the highest. Further, since the aspect ratio b / L ≦ 1.1, the ratio of the blade area input is optimal, the blade is well balanced, and the noise can be reduced to the lowest. That is, when the number of blades is two and a part of the vertical hub is cut out and the cutout portion 4c is provided, as the most mixed flow fan impeller, the material input can be reduced, the cost can be reduced, and the fluid friction Fan efficiency is high.

  In the third invention, in particular, the thickness of the hub side of the first or second blade is set larger than the thickness of the tip side, and the weight of the blade on the outer peripheral side is small, so the centrifugal force applied to the hub is small, Even if the mixed flow fan impeller is rotated at a high speed, the risk of breakage from the hub portion can be reduced.

  4th invention rotationally drives an air conditioner to a heat exchanger, a compressor, the mixed-flow fan impeller of any one of Claims 1-3, and the mixed-flow fan impeller. It is equipped with a motor, and the fan efficiency of the mixed flow fan impeller is high, so the motor input can be reduced, the energy consumption efficiency (COP) as an air conditioner can be increased, and the operation of the air conditioner Noise can be reduced. Furthermore, the cost of the mixed flow blower impeller can be reduced and the air conditioner can be manufactured at a low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The mixed flow fan impeller in the 1st Embodiment of this invention is demonstrated using FIGS.

  1 is a meridional view of the mixed flow fan impeller of the present invention, FIG. 2 is a radial sectional view of the mixed flow blower impeller, FIG. 3 is a plan view of the mixed flow blower impeller, and FIG. FIG. 5 is a plan view seen from the leeward side of the mixed-flow fan impeller, and FIG. 6 is a schematic view showing a usage example of the mixed-flow fan impeller.

  In FIG. 1, a mixed-flow fan impeller 1 of the present invention includes a substantially truncated cone-shaped hub 4 and a plurality of thin blades 6 provided on the hub 4, and a leading edge 2 of the blade 6. On the meridional surface of the wing 6 on the outer peripheral side from the vicinity of the midpoint (BB) between the hub 4 and the tip 5 of the wing 6 in a concave curve with respect to the windward side, and the midpoint (BB ) On the hub 4 side from the vicinity, it is formed to have a convex curve with respect to the windward side.

  Further, as shown in FIG. 2, the radial cross-sectional shape of the blade 6 is a concave curve with respect to the windward side from the vicinity of the midpoint (BB) near the midpoint (BB). ) The hub 4 side is formed to have a convex curve with respect to the windward side. Furthermore, as shown in FIG. 3, on the plan view of the mixed flow fan impeller 1, the leading edge 2 is configured by a spiral curve. CC is the axial center line of the mixed flow fan impeller 1.

  Between the conical hub 4a directly connected to the suction surface side of the blade 6 (the upwind side surface of the blade 6 in FIG. 2), the pressure surface side of the blade 6 starts from the vicinity of the minimum radius of the conical hub 4a (the blade 6 in FIG. 2). The conical hub 4a and the vertical hub 4b are continuously connected to each other so that there is no missing portion in the hub 4, and the wing 6 In addition, a portion on the leeward side of the vertical hub 4b is cut out to form a cutout portion 4c, leaving a margin for the stepped portions of the conical hub 4a and the vertical hub 4b.

  Further, as shown in FIG. 2, when the blade thickness on the hub 4 side of the blade 6 is t1, and the blade thickness on the tip side is t2, the relationship is set so that the dimensional relationship of t1> t2.

The usage example of the mixed flow fan impeller 1 will be described with reference to FIG. When the mixed flow blower impeller 1 is accommodated in an appropriate orifice 7 and the mixed flow blower impeller 1 is driven by the motor 8, the rotation exerts a blowing action. In each figure, the arrow indicates the direction of airflow. The swirling arrows in FIG. 2 indicate blade tip vortices generated on the suction surface of the blade 6.

  The operation and action of the mixed flow blower impeller 1 configured as described above will be described.

  Due to the leakage flow from the pressure surface of the blade 6 toward the suction surface, generation of a blade tip vortex generated on the suction surface (upper surface of the blade 6 in FIG. 2) near the outer peripheral side of the blade 6 is generated in the concave curved portion of the blade 6. To promote. Further, the convex curved portion of the blade 6 on the hub 4 side facilitates radial inflow in a high load region. Furthermore, since the leading edge 2 is formed by a spiral curve, the sharp intersection of the leading edge 2 and the tip 5 is a point that defines the generation of the blade tip vortex. It clearly defines the beginning of vortex generation and promotes the generation of tip vortices.

  Moreover, since the front edge 2 is comprised by the spiral curve, the timing cut off with air will shift | deviate more smoothly.

  As described above, the flow of the entire mixed-flow fan impeller 1 is achieved by the regulation and promotion of the generation of the blade tip vortex, the smooth inflow in the radial direction, and the front edge 2 smoothly cutting off the air. It is possible to optimize the condition, and to reduce noise and fan efficiency more than before.

  Further, since the cut-off portion 4c is formed by cutting out the leeward side portion of the vertical hub 4b, the pressure inside the hub 4 is low when the air flow is about to pass through the mixed flow fan impeller 1. The flow around the inside is exhibited by the cutout portion 4c of the vertical hub 4b to optimize the flow state of the mixed flow fan impeller 1 as a whole, and the suction surface near the outer peripheral side of the blade 6 In combination with the action of promoting the generation of the blade tip vortex generated in the concave curved portion of the blade 6, it is possible to realize the most complete air flow state in the mixed flow fan impeller 1, thereby reducing noise and fan efficiency. Can be improved more than before. In addition, since the vertical hub 4b has the cutout portion 4c, the material used can be reduced correspondingly, and the cost of the mixed flow blower impeller 1 can be reduced.

  Specifically, in an experiment conducted by mounting a mixed flow blower impeller with a fan diameter of 395 on an outdoor unit (not shown) of an air conditioner, there is no case where the vertical hub 4b has a cutout portion 4c. Compared to the case, the fan efficiency ratio was excellent by about 2%, and the noise was 0.3 dB lower.

  Further, when the mixed flow fan impeller 1 is made of resin or the like, since the cutout portion 4c is provided in the vertical hub 4b, the rotational strength of the blades 6 of the mixed flow fan impeller 1 is weakened. In the embodiment, since the thickness of the blade 6 is set so as to satisfy the relationship of t1> t2, the weight of the outer blade 6 is reduced, the centrifugal force applied to the hub 4 is small, and the mixed flow blower impeller 1 is used. Even if it is rotated at a high speed, the risk of breakage from the hub 4 portion can be reduced. Specifically, in the strength analysis of the Φ395 mixed flow fan impeller 1, when t1 = 4 mm and t2 = 2 mm, the deflection rate of the blades 6 is reduced to 1/3 compared to the case where the thickness is constant 3 mm. It was possible to reduce it.

(Embodiment 2)
The mixed flow fan impeller in the 2nd Embodiment of this invention is demonstrated using FIGS. In addition, about the same part as the mixed flow fan impeller in the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  FIG. 7 is a plan view of the mixed flow fan impeller in the present embodiment, FIG. 8 is a blade cross-sectional development view along the flow path center line (BB) of the mixed flow blower impeller, and FIG. It is a performance diagram of the aspect ratio and the air volume per noise in an outdoor unit of an air conditioner equipped with a mixed flow fan impeller having a diameter of Φ395.

  7-9, the mixed-flow fan impeller 1 in this Embodiment is the radius r1 to the midpoint of the hub 4 on the front edge 2, and the chip | tip 5 in the meridian surface of the blade | wing 6 (refer FIG. 1). And a radius r2 (see FIG. 1) between the hub 4 on the rear edge 3 and the midpoint of the tip 5 (see FIG. 1), and a flow path center line BB (r1) connecting the midpoint of the front edge 2 and the midpoint of the rear edge 3 And a longitudinal chord length L (FIG. 8) in the cross-sectional developed shape of the center line connecting r2 and r2, and a radial length b (FIG. 1) of the blade 6 on a radius of R = (r1 + r2) / 2, and an aspect ratio b /L≦1.1, the number of blades is two, and the leading edge 2 is a spiral curve.

  FIG. 4 is a diagram in which the number of blades 6 is three, but if only the number of blades is replaced with two, the present embodiment can be applied. Between the conical hub 4a directly connected to the suction surface side of the blade 6 is provided a vertical hub 4b starting from the vicinity of the minimum radius of the conical hub 4a and directly connected to the pressure surface side of the blade 6 in a substantially vertical direction. The vertical hub 4b is connected to the vertical hub 4b so that these hubs 4 have no missing portions, and the vertical hub 4b leaves a margin for the step portions of the blades 6, the conical hub 4a, and the vertical hub 4b. The mixed-flow fan impeller 1 which cut off the part of the leeward side of this is provided.

  The operation and action of the mixed flow blower impeller 1 configured as described above will be described.

  Since the number of blades 6 is composed of two, the number of blades 6 is the smallest, the blade area input is the least, and the fluid friction is small, so the fluid friction per aerodynamic work due to the blade area is small, so the fan efficiency is the highest. Get higher. Further, since the aspect ratio b / L ≦ 1.1, the ratio of the blade area input is appropriate, the blade 6 is well balanced, and the lowest noise can be achieved.

  Specifically, as shown in FIG. 9, in the mixed flow blower impeller 1 having a fan diameter of Φ395, the air volume per 38 dB is high when the aspect ratio b / L ≦ 1.1, but the aspect ratio exceeds 1.1. The air volume will be significantly reduced. Further, since the leeward side portion of the vertical hub 4b is cut off, when the air flow is about to pass through the mixed flow fan impeller 1, the pressure inside the hub 4 is low, so that the air flows around the inside. The blade tip vortex generated on the suction surface near the outer peripheral side of the blade 6 can be achieved by optimizing the flow state of the mixed flow blower impeller 1 as a result of the action induced by the cutout portion 4c of the vertical hub 4b. Combined with the action of accelerating the generation of air at the concave curved portion of the blade 6, it is possible to realize the most complete air flow state in the mixed flow fan impeller 1, so that noise reduction and fan efficiency can be improved more than before. Is.

  That is, in the mixed flow blower impeller 1 in which the number of blades is two and the cutout portion 4c is provided in the vertical hub 4b, the material input is small, the fluid friction is low, and the fan efficiency is high. Further, since the cutout portion 4c is provided in the vertical hub 4b, the material can be reduced, and the cost of the mixed flow blower impeller 1 can be reduced. Specifically, in an experiment in which a mixed flow blower impeller with a fan diameter of Φ395 is mounted on an outdoor unit of an air conditioner, the case where the vertical hub 4b has the cutout portion 4c is compared with the case where there is no cutout portion 4c. Thus, the fan efficiency ratio is excellent by about 2%, and the noise is 0.3 dB lower.

(Embodiment 3)
FIG. 10 is a cross-sectional view of an air conditioner according to the third embodiment of the present invention. In addition, about the same part as the mixed flow fan impeller in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 10, the air conditioner in the present embodiment includes a compressor 20, a heat exchanger 21, a mixed-flow fan impeller 1 detailed in the above-described embodiment, and a mixed-flow fan impeller 1. , A front grille 24, and an orifice 23, and air is sent to the heat exchanger 21 by the mixed flow fan impeller 1, and the fan efficiency of the mixed flow fan impeller 1 is improved. Since it is high, the input of the motor 22 can be reduced, the energy consumption efficiency (COP) as an air conditioner can be increased, and the operating noise of the air conditioner can be reduced. Furthermore, since the mixed flow fan impeller 1 is inexpensive, an air conditioner can be manufactured at a low cost.

  As described above, the mixed flow fan impeller according to the present invention is low in noise, excellent in fan efficiency, and has a cutout portion in the vertical hub, so that the material used can be reduced and can be formed at low cost. It can be widely applied to various industrial products using a fan, such as an air conditioner, a fan, a ventilation fan, and a fan for cooling a CPU of a computer.

Meridian view of mixed flow fan impeller in Embodiment 1 of the present invention Radial cross section of the mixed flow fan impeller Top view of the mixed flow fan impeller Perspective view of the mixed flow fan impeller Plan view seen from the leeward side of the mixed flow fan impeller Schematic showing the usage example of the mixed flow fan impeller The top view of the mixed flow fan impeller in Embodiment 2 of this invention Blade cross-sectional development view at the flow path center line of the mixed flow fan Performance diagram of aspect ratio and air volume per noise in outdoor unit of air conditioner equipped with same mixed flow fan impeller Cross-sectional view of an air conditioner according to Embodiment 3 of the present invention Meridian view of conventional mixed-flow fan impeller Perspective view of the mixed flow fan impeller Plan view from the leeward side of the mixed flow fan impeller

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diagonal-flow blower impeller 2 Front edge 3 Rear edge 4 Hub 4a Conical hub 4b Vertical hub 4c Cutout part 5 Tip 6 Wing 8, 22 Motor 20 Compressor 21 Heat exchanger 22 Fan motor 23 Orifice 24 Front grille

Claims (4)

In a mixed flow fan impeller comprising a plurality of thin blades provided on a substantially frustoconical hub, the leading edge of the blade is the midpoint of the hub and the tip of the blade on the meridian surface of the blade. A curved shape that is concave with respect to the windward side on the outer peripheral side from the vicinity, and a curved curve that is convex with respect to the windward side on the hub side from the vicinity of the midpoint, and the radial sectional shape of the blade is A curve that is concave with respect to the windward side from the vicinity of the midpoint, and a curve that is convex with respect to the windward side from the vicinity of the midpoint, is formed on the suction side of the blade. Between the conical hubs directly connected to each other, a vertical hub that starts from the vicinity of the minimum radius of the conical hub and is directly connected to the pressure surface side of the blade in a substantially vertical direction is provided, and the conical hub and the vertical hub are continuously connected. Connect these cones and vertical hubs so that there are no missing parts. Together, the wing and the conical hub, leaving the cash against the stepped portion of the vertical hub, diagonal flow fan impeller cut out portion of the leeward side of the vertical hub. The number of wings is 2, and the radius between the hub on the leading edge and the midpoint of the tip is r1 on the meridian surface of the wing, and the radius between the hub on the trailing edge and the midpoint of the tip is r2. L = (r1 + r2) / R = (r1 + r2) / where L is a chord length in a cross-sectional developed shape of the blade at a flow path center line (center line connecting r1 and r2) connecting the midpoints of the leading edge and the trailing edge. The mixed flow blower impeller according to claim 1, wherein the radial length of the blade on the radius of 2 is b, and the aspect ratio is b / L ≦ 1.1. The mixed flow blower impeller according to claim 1 or 2, wherein the thickness of the blade on the hub side is set larger than the thickness on the tip side. An air conditioner comprising a heat exchanger, a compressor, the mixed flow blower impeller according to any one of claims 1 to 3, and a motor that rotationally drives the mixed flow blower impeller.

Images