JPH10227295A - Impeller for propeller fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a high fan performance and also reduce an air force noise effectively at every operation state, in the impeller for a propeller fan. SOLUTION: The section shape near an impeller outer periphery edge 3e in a first area W, of the range from the front edge side end part 3h of an impeller 3 upto 2/3 of the length of an impeller outer periphery edge 3e is formed in a nearly wedge shape consisting of a negative pressure surface 3a extending in a straight line, straight line surface part 10 extending toward a pressure surface side with a prescribed included angle between a tip edge of the negative pressure surface 3a and the negative pressure surface 3a and an arc surface part continuing smoothly by an arc expanding the straight line surface part 10 and the pressure surface to the pressure surface side. When air is sucked in from the impeller outer periphery edge 3e side in the first area W, air flows to the pressure surface side along the straight line surface part 10 hardly being affected by the change of the flow-in angle. The air flowing along the straight line surface part 10 flows to the pressure surface side along the arc surface part due to the Coanda effect of the arc surface part and a high ventilation performance is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade structure of an impeller for a propeller fan, and more particularly, to a shape of a blade near a blade outer peripheral edge and a pressure surface.

[0002]

2. Description of the Related Art FIGS. 16 and 17 show a conventional propeller fan 21. FIG. This propeller fan 21
An impeller 22 having a plurality of blades 23 provided at a predetermined pitch in the circumferential direction on the outer peripheral surface of the hub 24, and a fan guide 25 arranged on the outer peripheral side of the impeller 22. I have.

[0003] By the way, in such a propeller fan 21, as shown in FIG.
Is mounted with the end near the blade trailing edge 23d included in the fan guide 25. In this case, the separation of the air flow is suppressed regardless of the fluctuation of the air inflow angle (the so-called “air foil effect”). 18), the so-called "airfoil" in which the blades 23 are made thicker like an airplane wing or a bird's wing and distribution is given to the wall thickness in the chord length direction as shown in FIG. Wing structure "has been attempted.

On the other hand, in the propeller fan 21, as shown by an air flow line A in FIG. 17, air is sucked not only from the front side of each blade 23, 23,. Is also performed. For this reason, a propeller fan 21 having blades 23 having a thick airfoil wing structure
In this case, the shape of the blade outer peripheral edge 23e of the blade 23 greatly affects the fan performance.

[0005] From such a background, for example, Japanese Unexamined Patent Application Publication No.
Japanese Patent No. 47193 proposes that an arcuate surface 23j in which the corner of the blade outer peripheral edge 23e of the blade 23 on the pressure surface 23b side is smoothly cut into an arc shape as shown in FIG. By doing so, air near the blade outer peripheral edge 23e can be smoothly sucked into the impeller 22 side.

[0006] Generally, a blade 2 having an airfoil wing structure is used.
23, as shown in FIG.
e to the blade inner peripheral edge 23g on the outer peripheral surface 24a side of the hub 24 are set substantially the same.

[0007]

By the way, in the case of the blade structure as in the above-mentioned known example, as described below, the air flow at the blade outer peripheral edge 23e and the pressure surface 23b
Both of the above airflows had their own problems.

First, the problem in the blade outer peripheral edge 23e is as follows. That is, when the flow of air flowing from the blade outer peripheral edge 23e side of the blade 23 is viewed, as shown in FIGS. 20 and 21, the flow velocity V of the flowing air is directed toward the center of the impeller along the negative pressure surface 23a. And the axial velocity component Va from the negative pressure surface 23a to the pressure surface 23b. In this case, propeller fan 2
In the rated operation of No. 1 as shown in FIG. 20, since the axial velocity component Va is relatively large, the inflow air is
From the leading edge 23a ₁ of the suction surface 23a along an arcuate surface 23j that is continuous with the pressure surface 23b smoothly flows in 3e portions, good blowing performance is ensured.

However, when the load increases due to the increase of the ventilation resistance, the amount of air flowing in from the blade leading edge 23c side decreases with the decrease of the air flow. As a result, as shown in FIG. 21, the axial velocity component Va becomes smaller as compared with the rated operation, and the airflow flowing from the blade outer peripheral edge 23e collides with the arc surface 23j of the blade outer peripheral edge 23e, The large wing tip vortex B is generated on the pressure surface 23b side by peeling off from the arc surface 23j side, which causes a decrease in air blowing performance.
Such a problem is peculiar to the blade 23 having an airfoil blade structure having a thickness distribution in the chord length direction.
Fan guide 2 where the suction flow from the side is locally large
5 becomes more prominent near the entrance.

As shown in FIG. 22, in a portion where the suction flow from the blade outer peripheral edge 23e is not caused by being included in the fan guide 25, as shown in FIG. since the leakage flow to the side occurs, the shape of only the pressure surface 23b side provided with the arcuate surface 23j by cutting in an arc shape, tip and peeling leakage flow at the tip end 23a ₁ of the suction surface 23a The vortex B is emitted and the aerodynamic noise increases.

On the other hand, problems in the pressure surface 23b of the blade 23 are as follows. That is, when air is sucked into the impeller 22 side, of the suction air, the airflow flowing from the direction substantially perpendicular to the pressure surface 23 b of the blade 23 is a centrifugal force caused by the rotation of the impeller 22. Affected by Therefore, the pressure surface 23b side, as shown in FIG. 23 by air flow lines A _0, flow toward the blade outer peripheral edge 23e side from the blade inner peripheral edge 23g side (hereinafter, referred to as "centrifugal flow") that occurs become.

As a result, as shown in FIG. 24, when the blades 23 are viewed from the pressure surface 23b side, the air sucked from the vicinity of the front edge 23c of the blade front edge 23c and the blade outer peripheral edge 23e, Under the influence of the centrifugal flow, as shown by air flow lines A, A,..., The air is gradually deflected toward the blade outer peripheral edge 23e as approaching the blade trailing edge 23d. Therefore, the air can be actually sucked smoothly from the blade outer peripheral edge 23e side in the entire area of the blade outer peripheral edge 23e in the range of about 30 to 50% from the blade front edge 23c side. Also the above blade trailing edge 23d
In the closer part, the above-mentioned centrifugal flow impedes the air suction action.

If the suction of air is hindered on the blade outer peripheral edge 23e side, the leakage flow from the pressure surface 23b side to the negative pressure surface 23a side on the blade outer peripheral edge 23e side of the blade 23 is caused by this. Increases, and no effective ventilation work is performed in the vicinity of the hub 24 on the blade trailing edge 23d side. As a result, the aerodynamic performance of the impeller 22 is reduced, and the aerodynamic noise of the propeller fan 21 is extended. Will increase.

In view of the above-mentioned problems, the present invention has been made to provide a propeller fan impeller that can ensure high air blowing performance in all operating states and effectively reduce aerodynamic noise. It is.

[0015]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

According to the first aspect of the present invention, in a propeller fan impeller provided with a plurality of thick blades 3 at a predetermined pitch in a circumferential direction on an outer periphery of a hub 4 and arranged inside a fan guide 5, the blade outer peripheral edge 3 in the first region W ₁ located in a range from the leading edge side end portion 3h to 2/3 of the length of the blade outer peripheral edge 3e of the blade outer peripheral edge 3e of the blade 3
The e vicinity of the cross-sectional shape, and a negative pressure surface 3a extending straight, linearly extending toward the pressure surface 3b side with a predetermined included angle θa between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a The linear surface portion 10, the linear surface portion 10, and the pressure surface 3b
Are formed in a substantially wedge-like shape formed by an arc surface portion 14 which smoothly extends in an arc protruding toward the pressure surface 3b.

According to a second aspect of the present invention, there is provided an impeller for a propeller fan in which a plurality of thick blades 3 are provided at a predetermined pitch in a circumferential direction on an outer periphery of a hub 4 and are arranged inside a fan guide 5. the blade outer peripheral edge 3 in the first region W ₁ located in a range from the leading edge side end portion 3h to 2/3 of the length of the blade outer peripheral edge 3e of the blade outer peripheral edge 3e of the blade 3
The e vicinity of the cross-sectional shape, and a negative pressure surface 3a extending straight, linearly extending toward the pressure surface 3b side with a predetermined included angle θa between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a A bent surface portion including a first straight surface 12 and a second straight surface 13 which is continuous with the first straight surface 12 and forms a bent surface bulging toward the pressure surface 3b between the first straight surface 12. 1
1, and the second linear surface 13 and the pressure surface 3b of the bent surface portion 11 are formed in a substantially wedge shape comprising an arc surface portion 14 that smoothly continues with an arc bulging toward the pressure surface 3b. Features.

According to a third aspect of the present invention, in the impeller for a propeller fan according to the first aspect, the outer peripheral edge 3e of the blade 3 extends from the rear edge 3i to the outer peripheral edge 3e.
e in the range of up to 1/3 of the length and the fan guide 5
The blade outer peripheral edge 3 in the second region W ₂ not covered by
The e vicinity of the cross-sectional shape, and a negative pressure surface 3a extending straight, linearly extending toward the pressure surface 3b side with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a A linear surface portion 15, the linear surface portion 15, and the pressure surface 3b;
Substantially with the wedge shape, the included angle the suction surface 3a .theta.b a in the first region W ₁ and the straight line surface portion 10 formed of a circular surface 19 smoothly continuous with an arc that bulges bets to the pressure surface 3b side The angle is set to be smaller than the included angle θa.

According to a fourth aspect of the present invention, in the impeller for a propeller fan according to the second aspect, of the blade outer peripheral edge 3e of the blade 3 from the trailing edge 3i to the blade outer peripheral edge 3e.
e in the range of up to 1/3 of the length and the fan guide 5
The blade outer peripheral edge 3 in the second region W ₂ not covered by
The e vicinity of the cross-sectional shape, and a negative pressure surface 3a extending straight, linearly extending toward the pressure surface 3b side with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a A bent surface portion including a first straight surface 17 and a second straight surface 18 which is continuous with the first straight surface 17 and forms a bent surface bulging toward the pressure surface 3b between the first straight surface 17. 1
6, and the second linear surface 18 and the pressure surface 3b of the bent surface portion 16 are formed in a substantially wedge-like shape comprising an arc surface portion 19 that smoothly continues with an arc swelling toward the pressure surface 3b.
The suction surface 3 of the included angle θb of the first region W ₁
a is set to an angle smaller than the included angle θa between the “a” and the first straight surface 12 of the bent surface portion 11.

According to a fifth aspect of the present invention, in the impeller for a propeller fan according to the first aspect, the outer peripheral edge 3e of the blade 3 extends from the trailing edge 3i to the outer peripheral edge 3e.
e in the range of up to 1/3 of the length and the fan guide 5
The blade outer peripheral edge 3 in the second region W ₂ not covered by
The e vicinity of the cross-sectional shape, and a negative pressure surface 3a extending straight, linearly extending toward the pressure surface 3b side with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a A bent surface portion including a first straight surface 17 and a second straight surface 18 which is continuous with the first straight surface 17 and forms a bent surface bulging toward the pressure surface 3b between the first straight surface 17. 1
6, and the second linear surface 18 and the pressure surface 3b of the bent surface portion 16 are formed in a substantially wedge-like shape comprising an arc surface portion 19 that smoothly continues with an arc swelling toward the pressure surface 3b.
The suction surface 3 of the included angle θb of the first region W ₁
The angle is set to be smaller than the included angle θa between “a” and the straight surface portion 10.

According to a sixth aspect of the present invention, in the impeller for a propeller fan according to the second aspect, of the blade outer peripheral edge 3e of the blade 3 from the trailing edge 3i to the blade outer peripheral edge 3e.
e in the range of up to 1/3 of the length and the fan guide 5
The blade outer peripheral edge 3 in the second region W ₂ not covered by
The e vicinity of the cross-sectional shape, and a negative pressure surface 3a extending straight, linearly extending toward the pressure surface 3b side with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a A linear surface portion 15, the linear surface portion 15, and the pressure surface 3b;
With a substantially wedge shape formed of the circular surface 19 smoothly continuous with the circular arc that bulges bets to the pressure surface 3b side, the suction surface 3a and the bent surface portions of the included angle θb of the first region W ₁ 11 and the included angle θa with the first linear surface 12
It is characterized in that it is set at an angle smaller than that.

According to a seventh aspect of the present invention, there is provided an impeller for a propeller fan in which a plurality of thick blades 3 are provided at a predetermined pitch in a circumferential direction on an outer periphery of a hub 4 and are arranged inside a fan guide 5. A third region W of the blade 3 from the trailing edge 3i of the blade outer edge 3e to one third of the length of the blade outer edge 3e and included in the fan guide 5.
The cross-sectional shape in the vicinity of the blade outer peripheral edge 3e in FIG. ₃ is a curved surface shape having the same curvature and having an arcuate surface portion 20 composed of arcuate surfaces 20a and 20b continuous with the suction surface 3a and the pressure surface 3b, respectively. Features.

In the eighth invention of the present application, the first, second,
In the propeller fan impeller according to the third, fourth, fifth or sixth aspect of the present invention, from the trailing edge 3i of the outer peripheral edge 3e of the blade 3 to one third of the length of the outer peripheral edge 3e. and the fan guide 5 the blade outer peripheral edge 3e near the cross-sectional shape in the third region W ₃ encompassed in a range of,
An arc surface portion 2 having the same curvature and having arc surfaces 20a and 20b continuous with the suction surface 3a and the pressure surface 3b, respectively.
It is characterized by having a curved surface shape with 0.

In the ninth invention of the present application, the first, second,
In the propeller fan impeller according to the third, fourth, fifth, sixth, seventh or eighth invention, the length of the blade camber at each radial position of the blade 3 and the front of the blade on the blade camber the thickness of the blade 3 in the point that the ratio of the distance from the edge 3c same each of the curves or straight lines L ₁ obtained by connecting each ratio, the circular surface 14, 19, 20 and the pressure The present invention is characterized in that the pressure surface 3b is curved so as to gradually decrease from the maximum thickness portion 3f in the vicinity of a continuous portion with the surface 3b toward the hub outer peripheral surface 4a.

According to a tenth aspect of the present invention, in the impeller for a propeller fan according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect of the present invention, above in each of the wing camber length and wings each curve camber vanes on previous obtained points to the ratio of the distance from the edge 3c same tie for each ratio or lines L ₁ at each radial position The thickness of the blade 3 is the maximum thickness portion 3 in the vicinity of a continuous portion between the arc-shaped surface portions 14, 19, 20 and the pressure surface 3b.
The pressure surface 3b of the blade 3 is curved so as to gradually decrease from f toward the hub outer peripheral surface 4a and increase again near the hub outer peripheral surface 4a.

According to an eleventh aspect of the present invention, in the propeller fan impeller according to the ninth or tenth aspect,
The range in which the pressure surface 3b of the blade 3 is bent is determined by the range of the blade 3
For the chord length S at each radial position, the blade leading edge 3c
Is set in a range from a position of 0.2S to a position of 0.9S.

In the twelfth invention of the present application, the ninth and the first aspects
In the impeller for a propeller fan according to the 0th or eleventh aspect, when the outer diameter of the impeller 2 is D ₀ and the outer diameter of the hub 4 is Dh, the blade camber at each radial position of the blade 3 is position of the maximum thickness portion 3f of the blade cross-section the point of the same ratio on each curve or a straight line L ₁ obtained by connecting each ratio of the distance from the blade leading edge 3c on the length and the wing camber Is set within a range defined by a diameter D ｛= ((D ₀ ² + Dh ² ) / 2) ^0.5と and an outer diameter D ₀ of the impeller 2.

According to a thirteenth aspect of the present invention, in the propeller fan impeller according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect of the present invention, Thickness,
From the thickest portion 3f near the continuation of the arc surface portions 14, 19, 20 and the pressure surface 3b, the hub outer peripheral surface 4a
It is characterized by being substantially the same toward.

In the fourteenth invention of the present application, the ninth and the first
The propeller fan impeller according to the 0th, eleventh, twelfth, or thirteenth invention is characterized in that the impeller 3 has a hollow structure having a cavity 6 inside its thickness.

In the fifteenth invention of the present application, the ninth and the first
In the propeller fan impeller according to the zeroth, eleventh, twelfth, or thirteenth invention, the impeller has a hollow structure formed by press-molding a sheet metal so as to have a hollow portion 6 inside its thickness. It is characterized by doing.

According to a sixteenth aspect of the present invention, in the propeller fan impeller according to the fifteenth aspect, the blades 3 are formed integrally with the hub 4 by press forming a sheet metal.

[0032]

According to the present invention, the following effects can be obtained by adopting such a configuration.

(A) The propeller fan impeller according to the first invention of the present application has a range from the leading edge side end 3h of the blade outer peripheral edge 3e of the blade 3 to 2/3 of the length of the blade outer peripheral edge 3e. The cross-sectional shape near the blade outer peripheral edge 3e in the first region W ₁ (that is, the region which is relatively close to the blade outer peripheral edge 3e and is not affected by the fan guide 5) has a negative pressure surface 3a extending linearly. And a leading edge 3a ₁ of the suction surface 3a.
And a linear surface portion 10 extending linearly toward the pressure surface 3b with a predetermined included angle θa between the pressure surface 3a and the negative pressure surface 3a, and the linear surface portion 10 and the pressure surface 3b bulge toward the pressure surface 3b. It has a substantially wedge shape composed of an arc surface portion 14 that smoothly continues in an arc.

[0034] If, according to such a configuration, the air from the blade outer peripheral edge 3e side in the first region W ₁ is sucked,
A tip edge 3a of the suction surface 3a at the outer peripheral edge 3e of the blade.
_Since the portion continuous to ₁ , that is, the portion corresponding first to the suction air is a straight surface portion 10 inclined with a predetermined included angle θa between itself and the suction surface 3a, the portion from the blade outer peripheral edge 3e is Even if the magnitude of the axial velocity component Vc of the intake air changes with a change in the load, the inflow angle of the intake air into the linear surface portion 10 is, for example, such that the outer peripheral edge 23 e of the blade is a negative pressure surface as in the above-mentioned known example. The leading edge 23a of 23a
_As compared with the case where the entire surface is formed as an arc from the _first side to the pressure surface 23b, the inflow air is hardly affected by a change in the inflow angle, and the inflow air follows the pressure surface It flows to the 3b side. Further, the air flowing along the linear surface portion 10 is further reduced by the linear surface portion 1.
Due to the Coanda effect of the arcuate surface portion 14 continuing to zero, the fluid flows smoothly toward the pressure surface 3b along the arcuate surface portion 14. As a result, the inflow air smoothly flows in without causing the tip vortex B from the blade outer peripheral edge 3e,
As a result, high air blowing performance is realized.

(B) The propeller fan impeller according to the second invention of the present application has a range from the leading edge side end 3h of the blade outer peripheral edge 3e of the blade 3 to 2/3 of the length of the blade outer peripheral edge 3e. The cross-sectional shape near the blade outer peripheral edge 3e in the first region W ₁ (that is, the region which is relatively close to the blade outer peripheral edge 3e and is not affected by the fan guide 5) has a negative pressure surface 3a extending linearly. And a leading edge 3a of the suction surface 3a.
₁ from the first straight line surface 12 and the first continuously in a linear surface 12 and the first straight face 12 extending linearly toward the pressure surface 3b side with a predetermined included angle θa between the negative pressure surface 3a A second linear surface 13 forming a bent surface bulging toward the pressure surface 3b side between the bent surface portion 11 and the second linear surface 13 and the pressure surface 3b of the bent surface portion 11 Surface 3b
It has a substantially wedge-like shape formed by an arc surface portion 14 that smoothly continues with an arc bulging to the side.

[0036] If, according to such a configuration, the air from the blade outer peripheral edge 3e side in the first region W ₁ is sucked,
A tip edge 3a of the suction surface 3a at the outer peripheral edge 3e of the blade.
Portion contiguous to _1, i.e., a portion corresponding to the first relative suction air, first straight surface extending linearly toward the pressure surface 3b side with a predetermined included angle θa between the suction surface 3a 12
Therefore, even if the magnitude of the axial velocity component Vc of the suction air from the blade outer peripheral edge 3e changes with the load, the inflow angle of the suction air into the first linear surface 12 is For example, as shown in the above-mentioned known example, the blade outer peripheral edge 23
e is the pressure surface 23b from the leading edge 23a ₁ side of the suction surface 23a.
The inflow air is hardly affected by a change in the inflow angle, and the second air continuous with the first straight surface 12 is hardly affected by the change in the inflow angle. It flows on the straight surface 13. Further, since the second linear surface 13 forms a bent surface bulging toward the pressure surface 3b between the first linear surface 12 and the first linear surface 12, for example, the first linear surface 12 and the second linear surface As compared with the case where the surface 13 extends linearly, the degree of deflection of the inflow air at the bent surface portion 11 becomes gentler, so that separation of the inflow air is further suppressed, and smooth air suction is realized. Further, the air flowing along the first straight surface 12 and the second straight surface 13 of the bent surface portion 11
Due to the Coanda effect of the arcuate surface portion 14 that continues to 3, the fluid flows smoothly toward the pressure surface 3b along the arcuate surface portion 14.

As a synergistic effect, the air sucked in from the blade outer peripheral edge 3e of the blade 3 flows in smoothly without generating the blade tip vortex B, thereby realizing high air blowing performance. .

[0038] (c) According to the third propeller fan impeller according to the invention of the present application, the addition to the effects in the first region W ₁ as described (a), the the following in the second region W ₂ Such a specific effect can be obtained. That is, this third
In the present invention, the second region W ₂ (from the trailing edge 3i of the blade outer peripheral edge 3e of the blade 3 to 1/3 of the length of the blade outer peripheral edge 3e and not included in the fan guide 5). in other words, the blade outer peripheral edge 3e near the cross-sectional shape in the area) near the inlet of the fan guide 5, a suction surface 3a extending linearly, between the leading edge 3a ₁ of the negative pressure surface 3a of the negative pressure surface 3a Pressure surface 3b with a predetermined included angle θb
A linear surface portion 15 extending linearly toward the side, and the linear surface portion 15 and the pressure surface 3b are formed in a substantially wedge shape having an arcuate surface portion 19 which is smoothly continuous with an arc bulging toward the pressure surface 3b. together, the included angle θa between the suction surface 3a and the linear surface portion 10 of the included angle θb of the first region W ₁
It is set to an angle smaller than.

With this configuration, the second region W
The basically in _two same effects as in the first region W ₁ is obtained. That is, if the air is sucked from the portion corresponding to the second region W ₂ of the blade outer peripheral edge 3e, portion contiguous in該羽wishes periphery 3e to the tip end 3a ₁ of the suction surface 3a, i.e., the suction air On the other hand, the first corresponding part is a predetermined included angle θb with the negative pressure surface 3a.
, The axial velocity component Vc of the suction air from the outer peripheral edge 3 e of the blade.
Even if the size of the suction air changes with the change in load, the inflow angle of the suction air into the linear surface portion 15 is small,
Therefore, the inflow air is hardly influenced by the change in the inflow angle, and is compressed along the linear surface portion 15 by the pressure surface 3b.
Flowing to the side. Further, the air flowing along the linear surface portion 15 is further arcuately connected to the linear surface portion 15.
Owing to the Coanda effect described above, the fluid flows smoothly toward the pressure surface 3b along the arc surface portion 14.

On the other hand, the effects specific to the second region W ₂ are as follows. That is, the second area W ₂ is a part immediately before the entrance of the fan guide 5 and the first area W ₁
At the portion closer to the trailing edge 3d of the blade, the suction of air is prevented by the presence of the fan guide 5, so that a flow flows along the inlet of the fan guide 5 and immediately before the inlet of the fan guide 5. since the air is collected from a wide range at the site, the flow velocity becomes faster than the other portions in the portion corresponding to the second region W ₂ of the blade outer peripheral edge 3e. In this case, as described above, this second
The included angle θb in blade outer peripheral edge 3e corresponding to the region W ₂ with respect to the suction surface 3a of the linear surface portion 15, the first
To be smaller than the included angle θa at the site corresponding to the region W _1,該羽wishes thinner wall thickness of the blade 3 in the peripheral 3e, it is reduced as much as possible that much resistance to early intake air flow velocity, resulting In addition, the air blowing performance can be improved.

The (d) The According to the propeller fan impeller according to a fourth aspect of the present invention, in addition to the effects in the first region W ₁ as described in (b) above are unique effects as follows Kanade Can be done. That is, in the fourth aspect of the present invention, the blade outer peripheral edge 3e of the blade 3 ranges from the trailing edge 3i to one third of the length of the blade outer peripheral edge 3e and is not included in the fan guide 5. suction surface 3a of the blade outer peripheral edge 3e near the cross-sectional shape in the region W _2, extends straight
If, continuous with the first straight line surface 17 and the first straight face 17 extending linearly toward the pressure surface 3b side with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a And a second linear surface 18 forming a bent surface bulging toward the pressure surface 3b between the first linear surface 17 and the second linear surface of the bent surface portion 16. 18 and the above-mentioned pressure surface 3b with a substantially wedge shape formed of the circular surface 19 smoothly continuous with an arc that bulges to the pressure surface 3b side, the negative pressure surface of the included angle θb of the first region W ₁ An angle smaller than the included angle θa between 3a and the first straight surface 12 of the bent surface portion 11 is set.

With this configuration, the second region W
The basically in _two same effects as in the first region W ₁ is obtained.

[0043] That is, if the air is sucked from the blade outer peripheral edge 3e side in the second region W _2,該羽wishes rim 3
portion continuous from the leading end edge 3a ₁ of the suction surface 3a at e, i.e., a portion corresponding to the first relative suction air, toward the pressure surface 3b side with a predetermined included angle θb between the suction surface 3a linear Even if the magnitude of the axial velocity component Vc of the intake air from the blade outer peripheral edge 3e changes with the load variation,
The inflow angle of the suction air with respect to the first linear surface 17 is:
For example, as shown in the above known example, the blade outer peripheral edge 23e is
smaller than the case where there is a generally arcuate surface over the pressure surface 23b from the distal end 23a ₁ side of a, thus, the inflow air without being almost affected by changes in the inflow angle, said first straight line It flows along a surface 17 to a second linear surface 18 which follows it. Further, since the second linear surface 18 forms a bent surface bulging toward the pressure surface 3b side with the first linear surface 17, for example, the first linear surface 1
7 and the second linear surface 18 extend linearly, the degree of deflection of the inflow air at the bent surface portion 16 becomes gentler, so that separation of the inflow air is further suppressed, and smooth air suction is performed. Is realized. further,
The first straight surface 17 and the second straight surface 18 of the bent surface portion 16
The air that has flowed along the arc surface 14 smoothly flows toward the pressure surface 3b along the arc surface 14 due to the Coanda effect of the arc surface 14 continuing to the second linear surface 18.

As a synergistic effect, the air sucked from the blade outer peripheral edge 3e of the blade 3 flows in smoothly without generating the blade tip vortex B, whereby high air blowing performance is realized. .

On the other hand, the effects specific to the second region W ₂ are as follows. That is, the second area W ₂ is a part immediately before the entrance of the fan guide 5 and the second area W ₂
At the portion closer to the trailing edge 3d of the blade, the suction of air is prevented by the presence of the fan guide 5, so that a flow flows along the inlet of the fan guide 5 and immediately before the inlet of the fan guide 5. since the air is collected from a wide range at the site, the flow velocity becomes faster than the other portions in the portion corresponding to the second region W ₂ of the blade outer peripheral edge 3e. In this case, as described above, this second
The included angle θb in blade outer peripheral edge 3e corresponding to the region W ₂ with respect to the suction surface 3a of the first straight surface 17 is made smaller than the included angle θa at the site corresponding to the first region W _1,該羽wishes The thickness of the blades 3 at the peripheral edge 3e is reduced, and the resistance to the intake air having a high flow velocity is reduced as much as possible, and as a result, the blowing performance can be improved.

(E) The propeller fan impeller according to the fifth aspect of the present invention has the following specific effects in addition to the effects described in the above (a). That is, in the fifth aspect of the present invention, in the blade outer peripheral edge 3 e of the blade 3, the range from the trailing edge 3 i to one third of the length of the blade outer peripheral edge 3 e is not included in the fan guide 5. the blade outer peripheral edge 3e near the cross-sectional shape in the region W _2, the negative pressure surface 3a extending straight, the pressure surface 3 with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a
a first straight surface 17 extending linearly toward the side b, and a second surface which is continuous with the first straight surface 17 and forms a bent surface bulging toward the pressure surface 3b between the first straight surface 17; Straight surface 1
8 and an arc surface portion 19 that smoothly continues the second linear surface 18 and the pressure surface 3b of the bent surface portion 16 in an arc bulging toward the pressure surface 3b. And the included angle θb is set to the first region W
_The angle between the negative pressure surface 3a and the first linear surface 12 of the bent surface portion 11 is set smaller than the included angle θa.

[0047] With such a configuration, if the air is sucked from the blade outer peripheral edge 3e side in the second region W ₂ of the blade outer peripheral edge 3e,該羽wishes distal edge 3a of the negative pressure surface 3a at the periphery 3e ₁ , That is, the first portion corresponding to the suction air is a first linear surface 17 extending linearly toward the pressure surface 3b with a predetermined included angle θb between the suction surface and the suction surface 3a. Therefore, even if the magnitude of the axial velocity component Vc of the suction air from the blade outer peripheral edge 3e changes with a change in load, the inflow angle of the suction air into the first linear surface 17 is, for example, As shown in the known example, the outer peripheral edge 23e of the blade is the leading edge 2 of the suction surface 23a.
Overall from 3a ₁ side to the pressure surface 23b smaller than the case where there is a circular arc surface, therefore, the incoming air without being almost affected by changes in the inflow angle, first
It flows along a straight surface 17 to a second straight surface 18 that follows it. Further, the second linear surface 18 corresponds to the first linear surface 17.
Between the first linear surface 17 and the second linear surface 18 in a straight line. The degree of deflection of the inflow air at the bent surface portion 16 becomes gentle,
As a result, the separation of the inflow air is further suppressed, and a smooth suction of air is realized. Further, the bent surface portion 1
The air flowing along the first straight surface 17 and the second straight surface 18 of 6 is smoothly moved along the arc surface 14 by the Coanda effect of the arc surface 14 continuing to the second straight surface 18 on the pressure surface 3b side. Will flow to As a synergistic effect, the air sucked in from the blade outer peripheral edge 3e of the blade 3 smoothly flows in without causing the blade tip vortex B, thereby achieving high air blowing performance.

On the other hand, the second area W ₂ is a fan guide 5
A site immediately before the inlet of, and since the suction of air is prevented by the presence of the fan guide 5 at the blade trailing edge 3d side portion than the second region W _2, the inlet of the fan guide 5 along flow occurs to flow, moreover, the other part from the air gather from a wide range just before the site of the inlet of the fan guide 5, the portions corresponding to the second region W ₂ of the blade outer peripheral edge 3e The flow velocity is faster than In this case, as described above, this second
The included angle θb in blade outer peripheral edge 3e corresponding to the region W ₂ with respect to the suction surface 3a of the first straight surface 17 is made smaller than the included angle θa at the site corresponding to the first region W _1,該羽wishes The thickness of the blades 3 at the peripheral edge 3e is reduced, and the resistance to the intake air having a high flow velocity is reduced as much as possible, and as a result, the blowing performance can be improved.

(F) The propeller fan impeller according to the sixth aspect of the present invention has the following specific effects in addition to the effects described in the above (b). That is, in the sixth aspect of the present invention, the blade outer peripheral edge 3e of the blade 3 ranges from the trailing edge 3i to one third of the length of the blade outer peripheral edge 3e and is not included in the fan guide 5. the blade outer peripheral edge 3e near the cross-sectional shape in the region W _2, the negative pressure surface 3a extending straight, the pressure surface 3 with a predetermined included angle θb between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a
a substantially wedge shape comprising a linear surface portion 15 extending linearly toward the side b, and an arc surface portion 19 which smoothly connects the linear surface portion 15 and the pressure surface 3b with an arc bulging toward the pressure surface 3b side. as well as, the included angle θ between the suction surface 3a and the linear surface portion 10 of the included angle θb of the first region W ₁
The angle is set smaller than a.

[0050] With such a configuration, if the air is sucked from the portion corresponding to the second region W ₂ of the blade outer peripheral edge 3e, the suction surface 3 in該羽wishes periphery 3e
Since the portion continuous to the leading edge 3a ₁ of a, i.e., the portion corresponding first to the suction air, is a straight surface portion 15 inclined with a predetermined included angle θb between the suction air and the suction surface 3a. Even if the magnitude of the axial velocity component Vc of the suction air from the outer peripheral edge 3e of the blade changes with the load, the inflow angle of the suction air with respect to the linear surface portion 15 is small. The fluid flows to the pressure surface 3b along the straight surface portion 15 without being substantially affected by the change in the angle. Further, the air flowing along the linear surface portion 15 further smoothly flows toward the pressure surface 3b along the arc surface portion 14 due to the Coanda effect of the arc surface portion 14 continuing to the linear surface portion 15.

On the other hand, the second area W ₂ is a fan guide 5
In the area immediately before the entrance of the airbag and at a position closer to the blade trailing edge 3 d than the first area W ₁ , the suction of air is prevented by the presence of the fan guide 5. Flows, and
Since air is collected from a wide area immediately before the entrance of the fan guide 5, the second portion of the blade outer peripheral edge 3 e
Flow rate becomes faster than the other portions in the portion corresponding to the region W _2. In this case, as described above, the linear surface portion 1 in the blade outer peripheral edge 3e corresponding to the second region W ₂
5 of the included angle θb relative to the negative pressure surface 3a, to be smaller than the included angle θa at the site corresponding to the first region W _1,該羽wishes periphery becomes thinner wall thickness of the blade 3 in 3e, early much flow velocity The resistance to the intake air is reduced as much as possible, and as a result, the blowing performance can be improved.

(G) In the propeller fan impeller according to the seventh aspect of the present invention, a plurality of thick blades 3 are provided on the outer periphery of the hub 4 at a predetermined pitch in the circumferential direction and inside the fan guide 5. In the propeller fan impeller to be arranged, the trailing edge 3i of the outer peripheral edge 3e of the blade 3
Has and the negative pressure surface of and the fan guide 5 the blade outer peripheral edge 3e near the cross-sectional shape in the third region W ₃ encompassed by, the same curvature in the range of up to one third of the length of the blade outer peripheral edge 3e from It has a curved surface shape having an arc surface portion 20 composed of arc surfaces 20a and 20b continuous with the pressure surface 3a and the pressure surface 3b, respectively.

According to this configuration, the suction of the third region W ₃ from the outer peripheral edge 3 e of the blade 3 is prevented by the presence of the fan guide 5, and the portion of the outer peripheral edge 3 e of the blade 3 from the pressure surface 3 b side. A leakage flow to the suction surface 3a side occurs. In this case, the blade outer peripheral edge 3e is formed by an arc surface portion having the same curvature and being formed by arc surfaces 20a and 20b continuous with the suction surface 3a and the pressure surface 3b, respectively. 20
Is formed, the leak flow smoothly flows along the arc surface portion 20 due to the Coanda effect in the arc surface portion 20, and as a result, the tip vortex B at the blade outer peripheral edge 3e portion Is suppressed as much as possible, and aerodynamic noise is effectively reduced.

(H) According to the propeller fan impeller according to the eighth aspect of the present invention, (a), (b),
In addition to the effects described in (c), (d), (e), or (f), the following specific effects can be obtained. That is, this sixth
The invention, in the third region W ₃ encompassed and to the fan guide 5 in the range from among trailing edge end 3i of the blade outer peripheral edge 3e of the blade 3 to 1/3 of the length of the blade outer peripheral edge 3e The cross-sectional shape in the vicinity of the blade outer peripheral edge 3e is a curved surface shape having the same curvature and having an arcuate surface portion 20 composed of arcuate surfaces 20a and 20b continuous with the suction surface 3a and the pressure surface 3b, respectively.

According to this configuration, the third region W ₃ is prevented from being sucked from the blade outer peripheral edge 3 e of the blade 3 by the presence of the fan guide 5, and the blade outer peripheral edge 3 e is located from the pressure surface 3 b side. A leakage flow to the suction surface 3a side occurs. In this case, the blade outer peripheral edge 3e is formed by an arc surface portion having the same curvature and being formed by arc surfaces 20a and 20b continuous with the suction surface 3a and the pressure surface 3b, respectively. 20
In this case, the leakage flow smoothly flows along the arcuate surface 20 due to the Coanda effect in the arcuate surface 20. As a result, the blade tip vortex at the blade outer peripheral edge 3e is formed. Generation of B is suppressed as much as possible, and aerodynamic noise is effectively reduced.

(I) According to the propeller fan impeller according to the ninth invention of the present application, the above (a), (b),
In addition to the effects described in (c), (d), (e), (f), (g) and (h), the following specific effects can be obtained. That is, in the seventh invention, the point that the ratio between the length of the blade camber at each radial position of the blade 3 and the distance from the blade leading edge 3c on the blade camber is the same is determined for each ratio. connecting in the thickness of the blade 3 in each of the curves or straight lines L ₁ is obtained, the maximum thickness portion 3 in the vicinity of the continuous portion between the circular surface 14, 19, 20 and the pressure surface 3b
The pressure surface 3b is curved so as to gradually decrease from f toward the hub outer peripheral surface 4a.

With this configuration, when air flows into the pressure surface 3b of the blade 3 from a direction substantially perpendicular to the pressure surface 3b, the air flows between the inflow direction of the inflow air and the surface direction of the pressure surface 3b. From the angle relationship, the incoming air is
As a component of the reaction force received from the fan, a component orthogonal to the fan rotation axis and directed toward the fan rotation axis is generated. By this reaction force component, the centrifugal flow based on the centrifugal force caused by the rotation of the impeller 2 is suppressed, and the blade against the air sucked from the vicinity of the front edge 3 h of the blade front edge 3 c and the blade outer peripheral edge 3 e is extended. The deflection action toward the outer peripheral edge 3e is reduced as much as possible. As a result, the leakage flow toward the negative pressure surface 3a at the outer peripheral portion of the pressure surface 3b is reduced, and the air blowing work is promoted near the hub 4 on the blade trailing edge 3d side, so that the aerodynamic performance of the impeller 2 is correspondingly increased. And aerodynamic noise is reduced.

(J) According to the impeller for a propeller fan according to the tenth invention of the present application, the above (a), (b),
In addition to the effects described in (c), (d), (e), (f), (g) and (h), the following specific effects can be obtained. That is, in the eighth aspect, the point that the ratio of the length of the blade camber at each radial position of the blade 3 to the distance from the blade leading edge 3c on the blade camber is the same for each ratio. connecting in the thickness of the blade 3 in each of the curves or straight lines L ₁ is obtained, the maximum thickness portion 3 in the vicinity of the continuous portion between the circular surface 14, 19, 20 and the pressure surface 3b
The pressure surface 3b of the blade 3 is curved so as to gradually decrease from f toward the hub outer peripheral surface 4a and increase again near the hub outer peripheral surface 4a.

With this configuration, when air flows into the pressure surface 3b of the blade 3 from a direction substantially perpendicular to the pressure surface 3b, the air flows between the flow direction of the inflow air and the surface direction of the pressure surface 3b. From the angular relationship, the incoming air is
As a component of the reaction force received from the fan, a component orthogonal to the fan rotation axis and directed toward the fan rotation axis is generated. By this reaction force component, the centrifugal flow based on the centrifugal force caused by the rotation of the impeller 2 is suppressed, and the blade against the air sucked from the vicinity of the front edge 3 h of the blade front edge 3 c and the blade outer peripheral edge 3 e is extended. The deflection action toward the outer peripheral edge 3e is reduced as much as possible. As a result, the leakage flow toward the negative pressure surface 3a at the outer peripheral portion of the pressure surface 3b is reduced, and the air blowing work is promoted near the hub 4 on the blade trailing edge 3d side, so that the aerodynamic performance of the impeller 2 is correspondingly increased. And aerodynamic noise is reduced.

Further, the thickness of the blade 3 is adjusted to the outer peripheral surface 4 of the hub.
Since it is made to increase again in the vicinity of a,
For example, the thickness in the vicinity of the hub outer peripheral surface 4a is larger than that in the case where the thickness of the blade 3 is gradually reduced from the maximum thickness portion 3f toward the vicinity of the hub outer peripheral surface 4a. The rigidity of the blades 3 is high by that much, and the reliability of the blades 3 in terms of strength and, in turn, the reliability of the blades 2 in terms of strength are enhanced.

(K) According to the impeller for a propeller fan according to the eleventh aspect of the present invention, the following specific effects can be obtained in addition to the effects described in the above (i) or (j). That is, in the ninth aspect, the range in which the pressure surface 3b of the blade 3 is curved is set such that the distance from the blade front edge 3c to the chord length S at each radial position of the blade 3 is 0.2S. Is set in the range from the position to the position of 0.9S.

In this case, since the blade 3 has an airfoil blade structure, the thickness of the blade front edge 3c is originally large, and the thickness of the blade rear edge 3d is small. I have. For this reason, as described above, on the blade leading edge 3c side, which is the portion where the airfoil effect is obtained most with a large thickness, the pressure surface 3b is not curved and the thickness is maintained without curving the high airfoil. The effect is secured,
Further, in the blade trailing edge 3d, whose rigidity is lower than that of the blade leading edge 3c due to its small thickness, the rigidity is reduced by maintaining the wall thickness without bending the pressure surface 3b. As a synergistic effect of these, it is possible to achieve both the airfoil effect and the reliability of the blades 3 while reducing the aerodynamic noise of the fan.

(L) According to the impeller for a propeller fan according to the twelfth aspect of the present invention, in addition to the effects described in the above (i), (j) or (k), the following specific effects can be obtained. Can be played. That is, in the tenth aspect, when the outer diameter of the impeller 2 is D ₀ and the outer diameter of the hub 4 is Dh, the length of the blade camber at each radial position of the blade 3 and the blade camber Each curve or straight line L ₁ obtained by connecting points having the same ratio with the distance from the blade leading edge 3c above for each ratio
The position of the maximum thickness portion 3f of the blade cross section on the
｛= ((D ₀ ² + Dh ² ) / 2) ^0.5 It is set within the range defined by the angle {} and the outer diameter D ₀ of the impeller 2.

In this case, the diameter D is the so-called blade 23
Is the average radius viewed from the total work amount of the above, and the portion outside the average radius is a portion that performs a larger air blowing work than the inside portion. Therefore, by setting the maximum thickness portion 3f of the blade 23 within the outer diameter D ₀ of the diameter D and the impeller 2, a portion of a larger blast work, the highest airfoil effect obtained Will be polymerized,
As a result, the aerodynamic performance of the impeller 2 is further enhanced.

(M) According to the impeller for a propeller fan according to the thirteenth invention of the present application, the above (a), (b),
In addition to the effects described in (c), (d), (e), (f), (g) and (h), the following specific effects can be obtained.
That is, in the thirteenth aspect, the thickness of the blade 3 is increased from the maximum thickness portion 3f near the continuous portion between the arc surface portions 14, 19, and 20 and the pressure surface 3b toward the hub outer peripheral surface 4a. (N) According to the impeller for a propeller fan according to the fourteenth invention of the present application, in addition to the effects described in the above (i), (j), (k) or (l), Specific effects such as That is, this first
In the invention of the first aspect, since the blade 3 has a hollow structure having a hollow portion 6 inside its thickness, the weight of the blade 3 is reduced as compared with a case where the blade 3 has a solid structure, for example. Therefore, the required driving power of the impeller 2 can be reduced or the strength performance can be improved.

(O) According to the propeller fan impeller according to the fifteenth aspect of the present invention, the above (i), (j),
The following specific effects can be obtained in addition to the effects described in (k) or (l). That is, in the twelfth aspect, the blade 3 has a hollow structure formed by press-molding a sheet metal so as to have the hollow portion 6 inside the thickness thereof. Has a hollow portion 6 formed by press-molding a sheet metal so as to have a cavity 6 inside, so that a high airfoil effect can be obtained while maintaining the low cost characteristic of a sheet metal blade. is there.

(P) According to the propeller fan impeller according to the sixteenth aspect of the present invention, the following specific effects can be obtained in addition to the effects described in the above (o). That is, in the thirteenth aspect, the blade 3 is connected to the hub 4
Since it is formed integrally with the sheet metal by press molding,
By forming the blades 3 integrally with the hub 4 by press molding of a sheet metal, the cost of the impeller 2 composed of the blades 3 and the hub 4 is reduced, and the ease of handling of the impeller 2 is improved. It is realized.

[0068]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred embodiment of a propeller fan impeller according to the present invention will be described. First Embodiment FIG. 1 shows an impeller 2 according to a first embodiment of the present invention.
In the figure, reference numeral 3 denotes a blade, which will be described in detail later, and reference numeral 4 denotes a hub. On the outer peripheral surface 4a of the hub 4, the blade 3 is provided at a predetermined pitch in the circumferential direction. Are attached to form the impeller 2. A fan guide 5 is arranged on the outer peripheral side of the impeller 2, and the fan guide 5 and the impeller 2 constitute the propeller fan 1.

The blade 3 has a so-called airfoil blade structure, and is integrally formed of a resin material. In this embodiment, the plurality of blades 3,
Are integrally formed with the hub 4, but in other embodiments, for example, the blades 3, 3,... Are individually formed, and these blades 3, 3,. Each of the hubs 4 formed separately may be retrofitted.

The impeller 2 according to this embodiment has the greatest feature in the shape of the blade 3 in the vicinity of the blade outer peripheral edge 3e. Hereinafter, the shape of the blade outer peripheral edge 3e of the blade 3 will be specifically described. I do.

The blade 3 has an aerofoil blade structure as described above, and has a thickness distribution such that the thickness gradually decreases from the blade front edge 3c side to the blade rear edge 3d side. This thickness distribution (see FIG. 18) is the same on the blade outer peripheral edge 3e side. And, in the one having the distribution of the thickness in the chord length direction as described above, as shown in FIG.
The blade is divided into three regions in the chord length direction, and the shape of the blade outer peripheral edge 3e is set after each of these regions. Specifically, it is as follows.

[0072] That is, first, the blade outer peripheral edge 3e corresponding to the relative position between the fan guide 5 as described next, the first region W ₁ and the second region W ₂ three third regions W ₃ Divided into regions. The first region W _1, of the entire area of the blade outer peripheral edge 3e, the leading edge side end portion 3h, the distance from the front edge end portion 3h is the length of the blade outer peripheral edge 3e against (L) (2
/ 3L), which is a region relatively far away from the inlet of the fan guide 5 to the upstream side of the air and has a large air intake from the blade outer peripheral edge 3e side.

The second region W ₂ is a region which is continuous with the end near the trailing edge of the first region W _1.
e is a region which is located within (1 / 3L) of the length (L) of the blade outer peripheral edge 3e from the trailing edge 3i and not included in the fan guide 5 in the entire region of e.
That is, the second area W ₂ is located immediately before the entrance of the fan guide 5 and is located closer to the blade trailing edge 3 d than the second area W ₂ , so that the air is sucked by the fan guide 5. Has been blocked. Therefore, in the second region W _2, flow occurs to flow along the inlet of the fan guide 5, moreover, since the air is collected from a wide range just before the site of the inlet of the fan guide 5, in another area In comparison, the flow rate of the suction air is faster.

The third region W ₃ is a region that is continuous with the rear edge of the second region W ₂ near the trailing edge, and is the blade outer peripheral edge 3.
Of the entire region e, the region is located within (1 / 3L) of the length (L) of the blade outer peripheral edge 3e from the trailing edge 3i and is included in the fan guide 5. Thus, the third region W ₃ being a suction is prevented from blade outer peripheral edge 3e of the blade 3 by the presence of the fan guide 5, a region where the leakage flow from the pressure surface 3b side to the negative pressure surface 3a side occurs.

Next, the shape of the blade outer peripheral edge 3e in each of the regions W _{1 to} W ₃ is as follows.

[0076] In the first region W _1, as shown in FIGS. 1 and 2, the cross-sectional shape of the blade outer peripheral edge 3e, and the suction surface 3a extending straight, the tip end 3a of the negative pressure surface 3a _A linear surface portion 1 extending linearly toward the pressure surface 3b with a predetermined included angle θa between the pressure surface 3a and the negative pressure surface 3a.
0, the linear surface portion 10 and the pressure surface 3b
It has a substantially wedge-like shape composed of an arc surface portion 14 that smoothly continues with an arc bulging to the b side.

In the second region W ₂ , as shown in FIGS. 1 and 3, the cross-sectional shape of the outer peripheral edge 3 e of the blade is basically the same as the structure of the first region W ₁ , that is, linear. The suction surface 3a extending to the front surface, and a leading edge 3a _{1 of the} suction surface 3a
, And a linear surface portion 15 extending linearly toward the pressure surface 3b with a predetermined included angle θb between the pressure surface 3a and the negative pressure surface 3a, and the linear surface portion 15 and the pressure surface 3b bulge toward the pressure surface 3b. Although it has a substantially wedge shape formed by an arc surface portion 19 that smoothly continues in an arc, in addition to this, the included angle θb
And it is set to an angle smaller than the included angle θa between the suction surface 3a and the linear surface portion 10 in the first region W _1.

[0078] In the third region W ₃ being as shown in FIGS. 1 and 4, the cross-sectional shape of the blade outer peripheral edge 3e, respectively continuous to and has and the negative pressure surface 3a and the pressure surface 3b of the same curvature An arc surface portion 20 composed of arc surfaces 20a and 20b
In particular, in this embodiment, the radius of curvature of each of the arc surfaces 20a and 20b is set to １ ／ of the thickness of the blade 3 at the corresponding portion. Therefore, in the outer peripheral edge 3e of the blade, the arc surface portion 20 is an arc surface that is continuous from the suction surface 3a to the pressure surface 3b.

As described above, by setting the cross-sectional shape of the blade outer peripheral edge 3e in each of the regions W _{1 to} W ₃ ,
Each following such action effects in respective regions W ₁ to _W-3 is obtained.

[0080] portion for continuous case, in該羽wishes periphery 3e to the tip end 3a ₁ of the suction surface 3a of the air from the blade outer peripheral edge 3e side in operation and effect of the first region W ₁ in the first region W ₁ is sucked That is, since the portion corresponding first to the suction air is the linear surface portion 10 inclined with a predetermined included angle θa between the suction air and the negative pressure surface 3a, as shown in FIG. Even if the magnitude of the axial velocity component Vc (see FIG. 20) of the intake air changes with the fluctuation of the load, the inflow angle of the intake air into the linear surface portion 10 is, for example, as shown in the above-mentioned known example. The peripheral edge 23e is the leading edge 23a _{1 of the} negative pressure surface 23a.
From the side to the pressure surface 23b is smaller than the case where the entire surface is an arc surface, so that the inflow air A is hardly affected by the change of the inflow angle and is formed along the straight surface portion 10 along the pressure surface. It will flow to the 3b side. Further, the air flowing along the linear surface portion 10 is further smoothly compressed along the arc surface portion 14 by the Coanda effect of the arc surface portion 14 continuing to the linear surface portion 10.
It will flow to the b side. As a result, the inflow air A flows in smoothly from the blade outer peripheral edge 3e without causing the blade tip vortex B, thereby realizing high air blowing performance.

[0081] Since in the above-described operation and effect the second region W ₂ in the second region W _2, is basically that has the same cross-sectional shape and cross-sectional shape of the blade outer peripheral edge 3e of the first region W ₁ The same effect can be obtained. That is, if the air is sucked from the portion corresponding to the second region W ₂ of the blade outer peripheral edge 3e, portion contiguous in該羽wishes periphery 3e to the tip end 3a ₁ of the suction surface 3a, i.e., the suction air The first corresponding site,
Since the linear surface portion 15 is inclined with a predetermined included angle θb between the suction surface 3a and the negative pressure surface 3a, the magnitude of the axial velocity component Vc of the suction air from the blade outer peripheral edge 3e varies with the load. Even if it does, the inflow angle of the suction air with respect to the straight surface portion 15 is small, so that the inflow air flows along the straight surface portion 15 to the pressure surface 3b side with almost no influence by the change in the inflow angle. Also,
The air that has flowed along the linear surface 15 further flows smoothly to the pressure surface 3b along the circular surface 14 due to the Coanda effect of the circular surface 14 that is continuous with the linear surface 15.

In addition to the above basic functions and effects, the following specific functions and effects can be obtained. That is, the second area W ₂
Since the site is a by and blade trailing edge 3d side portion than the second region W ₂ immediately before the inlet of the fan guide 5 suction of air is prevented by the presence of the fan guide 5, the fan guide occurs stream flowing along the inlet 5, moreover, since the air is collected from a wide range just before the site of the inlet of the fan guide 5, the portions corresponding to the second region W ₂ of the blade outer peripheral edge 3e Has a higher flow velocity than other parts. In this case, as described above, an included angle θ at the blade outer peripheral edge 3e corresponding to the second region W ₂ with respect to the suction surface 3a of the linear surface portion 15
b is an included angle θ at a portion corresponding to the first region W _1.
By making it smaller than a, the thickness of the blade 3 at the blade outer peripheral edge 3e becomes thinner, and the resistance to the suction air with a high flow velocity is reduced as much as possible, and as a result, the blowing performance can be improved. is there.

[0083] functions and effects of the third region W ₃ in the third region W ₃ being as described above, the suction from the blade outer peripheral edge 3e of the blade 3 by the presence of the fan guide 5 is prevented,該羽wishes periphery The portion 3e is a region where a leakage flow from the pressure surface 3b side to the negative pressure surface 3a side occurs. In this case, as in this embodiment, the blade outer peripheral edge 3e is provided with a curved surface portion 20 having the same curvature and having an arcuate surface portion 20 composed of arcuate surfaces 20a and 20b continuous with the suction surface 3a and the pressure surface 3b, respectively. By adopting the shape, the leak flow smoothly flows along the arc surface portion 20 due to the Coanda effect in the arc surface portion 20, and as a result, the generation of the tip vortex B in the blade outer peripheral edge 3e portion is reduced. As much as possible, aerodynamic noise is effectively reduced.

As described above, the impeller 2 of this embodiment
In the propeller fan 1 provided with the above, it is possible to achieve both high air blowing performance in all operation regions and realization of quiet operation by reducing aerodynamic noise.

Second Embodiment FIGS. 8 to 10 show sectional shapes of a blade outer peripheral edge 3e of a blade 3 of an impeller 2 according to a second embodiment of the present invention. In addition, the said blade | wing 3 in this embodiment
Have basically the same structure as the blade 3 in the first embodiment, and are different from those of the first embodiment in that the blade outer peripheral edge in each of the regions W _{1 to} W ₃ is different. Only the sectional shape of 3e is shown. Therefore, here, only the cross-sectional shape of the blade outer peripheral edge 3e in each of these regions W ₁ to _W-3 described with reference to FIGS. 8 to 10, for the other configurations incorporated the relevant description in the first embodiment Shall be.

[0086] cross-sectional shape of the blade outer peripheral edge 3e portion in cross-section the first region W ₁ of each region, as shown in FIG. 8, the suction surface 3a extending linearly
If, continuous with the first straight line surface 12 and the first straight face 12 extending linearly toward the pressure surface 3b side with a predetermined included angle θa between the negative pressure surface 3a from the leading edge 3a ₁ of the negative pressure surface 3a And a second linear surface 13 forming a bent surface bulging toward the pressure surface 3b between the first linear surface 12 and the second linear surface of the bent surface portion 11. 13 and the pressure surface 3b are formed in a substantially wedge shape comprising an arc surface portion 14 smoothly bulging toward the pressure surface 3b.

[0087] vane outer edge 3e of the second region W ₂
Portion of the cross-sectional shape, as shown in FIG. 9, the suction surface 3a extending linearly from the tip end 3a ₁ of the negative pressure surface 3a to the pressure surface 3b side with a predetermined included angle θb between the negative pressure surface 3a First linear surface 17 extending linearly toward the first linear surface 1
7 and a second linear surface 18 forming a bent surface bulging toward the pressure surface 3b between the first linear surface 17 and the first linear surface 17; with a substantially wedge shape formed of the circular surface 19 smoothly continuous with the second linear surface 18 and the pressure surface 3b by an arc that bulges to the pressure surface 3b side, the included angle θb of the first region W ₁ The angle between the negative pressure surface 3a and the first straight surface 12 of the bent surface portion 11 is set smaller than the included angle θa.

[0088] vane outer edge 3e of the third region W ₃
As shown in FIG. 10, the cross-sectional shape of the portion has the same curvature as the cross-sectional shape of the outer peripheral edge 3e of the blade, and has a negative pressure surface 3a.
Arc surfaces 20a and 20 continuous with the pressure surface 3b and the pressure surface 3b, respectively.
b having a curved surface portion having an arc surface portion 20,
In particular, in this embodiment, each of the arc surfaces 20a, 2
The radius of curvature of 0b is both set to の of the thickness of the blade 3 at the site. Therefore, in the outer peripheral edge 3e of the blade, the arc surface portion 20 is an arc surface that is continuous from the suction surface 3a to the pressure surface 3b.

With such a configuration, each of the regions W
_1, but in-region W ₃ in which each is Sose peculiar functions and effects, these operational effects in the third region W ₃ being as the operation and effect of the third region W ₃ in the first embodiment Are identical. Also, the operation and effect in the second region W _2, the first addition to the advantages in the area W _1, included angle θa of the included angle θb in the first region W ₁
Operational effect due to the smaller than merely is added, yet this additional effects and advantages are the same as those described in the effects of the second region W ₂ in the first embodiment. Thus, here, with reference to FIG. 11, it describes only operation and effect in the first region W _1, operation and effect in the second region W ₂ are effects as the first embodiment in the first region W ₁ the aid of appropriate explanation of, and operational effects in the third region W ₃ being the first
The corresponding description in the embodiment is referred to.

[0090] operation and effect in the first region W ₁ is as follows. In other words, the blade outer peripheral edge 3 in the first region W ₁
When air is sucked in from the e side, a portion of the blade outer peripheral edge 3e that is continuous with the leading edge 3a ₁ of the negative pressure surface 3a;
That is, the first portion corresponding to the suction air is the first straight surface 12 extending linearly toward the pressure surface 3b with a predetermined included angle θa between the suction air and the suction surface 3a.
Axial velocity component Vc of suction air from blade outer peripheral edge 3e
Even if the size of the suction air changes with the variation of the load, the inflow angle of the suction air with respect to the first linear surface 12 is, for example, such that the outer peripheral edge 23 e of the blade 23 a ₁ From the side to the pressure surface 23b, it is smaller than the case where the entire surface is formed as an arc surface, so that the inflow air is hardly affected by a change in the inflow angle along the first straight surface 12. Flows to the second straight surface 13 which is continuous with. Further, the second straight surface 13 corresponds to the first linear surface 13.
Since a bent surface swelling toward the pressure surface 3b is formed between the first linear surface 12 and the linear surface 12,
And the second linear surface 13 extends linearly, the degree of deflection of the inflow air at the bent surface portion 11 becomes gentler, and the separation of the inflow air is further suppressed accordingly,
Smooth air suction is realized. Further, the air flowing along the first straight surface 12 and the second straight surface 13 of the bent surface portion 11 flows along the arc surface portion 14 due to the Coanda effect of the arc surface portion 14 continuing to the second straight surface 13. It will flow smoothly to the pressure surface 3b side.

As a synergistic effect, the air sucked in from the blade outer peripheral edge 3e of the blade 3 smoothly flows in without causing the blade tip vortex B, thereby realizing high air blowing performance. .

Third Embodiment In the third embodiment, similarly to the blades 3 in the first and second embodiments, the outer peripheral edge 3e is formed by the first region W ₁ , the second region W ₂ and the third region W ₂ . in those sections into three parts in the region W _3, the first region W in the first embodiment as the cross-sectional shape of the blade outer peripheral edge 3e in a first region W _1
1 , while the second region W ₂
The cross-sectional shape of the blade outer peripheral edge 3e in is to the same structure and the second region W ₂ of the cross-sectional shape in the second embodiment.

With this configuration, in the first region W ₁ of the outer peripheral edge 3 e of the blade, the same operation and effect as those of the first region W ₁ in the first embodiment can be obtained. in the second region W _2, so that the same action and effects in the second region W ₂ in the second embodiment can be obtained.

Fourth Embodiment In a fourth embodiment, similarly to the blades 3 in the first and second embodiments, the outer peripheral edge 3e is formed by a first region W ₁ , a second region W ₂ and a third region W ₂ . in those sections into three parts in the region W _3, the first region W in the second embodiment as the cross-sectional shape of the blade outer peripheral edge 3e in a first region W _1
1 , while the second region W ₂
The cross-sectional shape of the blade outer peripheral edge 3e in is to the same structure and the second region W ₂ of the cross-sectional shape in the first embodiment.

[0095] By such a configuration, in the first region W ₁ of the blade outer peripheral edge 3e, same action and effects of the first region W ₁ in the second embodiment can be obtained and in the second region W _2, so that the same action and effects in the second region W ₂ in the first embodiment can be obtained.

Fifth Embodiment FIG. 12 shows a main part of a propeller fan 1 having an impeller 2 according to a fifth embodiment of the present invention. In FIG. A plurality of the blades 3 attached at a predetermined pitch in the circumferential direction on an outer peripheral surface 4a of the hub 4 to form the impeller 2; The propeller fan 1 is constituted by the fan guide 5 and the impeller 2, and the basic structure is the same as that of each of the above embodiments.

The impeller 2 according to the fifth embodiment includes:
The shape of the blade outer peripheral edge 3e and the pressure surface 3b of the blade 3 has the greatest feature, and the shape of the blade 3 will be specifically described below.

First, the shape of the blade outer peripheral edge 3e is the same as the shape of the blade outer peripheral edge 3e in the first embodiment in this embodiment. That is, as shown in FIG. 12 and FIG.
₁ and the second region W ₂ divided into three regions of the third region W _3, although and at different respective regions W ₁ to _W-3 shape for each cross section of each of these regions W ₁ to _W-3 shape are both identical to the cross-sectional shape of each region W ₁ to _W-3 of the first embodiment (shown cross-sectional shape of the first region W ₁ moiety is in Figure 13). Accordingly, each region W ₁ in the blade outer peripheral edge 3e is set.
Description of the cross-sectional shape of to _W-3, and with the aid of appropriate description of the first embodiment is operational effects based thereon will not be described here, in the following, only the shape of the pressure surface 3b of the blade 3 Will be described.

[0099] Description above blade 3 about the shape of the pressure surface 3b is a one having an airfoil blade structure as described above, in the section along the curve L ₁ in Figure 12, cross section as shown in FIG. 13 It is shaped. That is,
If it corresponds to the basic structure of conventional airfoil blades,
The negative pressure surface 3a of the blade 3 extends substantially linearly, and the pressure surface extends from the thickest portion 3f, which is the end of the arc surface portion 14 on the pressure surface 3b side, as indicated by a chain line 3b ', to the hub 4.
And extend in a substantially straight line with the same thickness toward the outer peripheral surface 4a.

However, in the blade 3 of this embodiment, the shape of the pressure surface 3b is applied from the maximum thickness portion 3f to the hub outer peripheral surface 4a as shown by a solid line in FIG. Curved. In particular,
After the thickness of the blade 3 at the cross-sectional position on the curve L ₁ is decreased gradually changes with the towards the blade in the periphery 3g side from the maximum thickness portion 3f from the blade outer peripheral edge 3e,
The pressure surface 3b is curved in a substantially S-shape so as to turn to increase in the vicinity of the inner peripheral edge 3g of the blade.

Here, the curve L ₁ connects points where the ratio of the length of the blade camber at each radial position of the blade 3 to the distance from the blade leading edge 3 c on the blade camber is the same. It is obtained and is set for each ratio.
Therefore, the blade 3 has a sectional shape as shown in FIG. 13 at positions corresponding to the respective curves L ₁ , L ₁ ,... Over the entire area from the blade leading edge 3c to the blade trailing edge 3d. Will have.

The impeller 2 provided with the blade 3 having the pressure surface 3b curved as described above has the following specific effects. That is, in the impeller 2, when air flows into the pressure surface 3b of the blade 3 from a direction substantially perpendicular to the pressure surface 3b, the pressure surface 3b moves from the maximum thickness portion 3f to the blade inner peripheral edge 3g. Since it is curved so as to gradually approach the negative pressure surface 3a as it goes, one of the components of the reaction force that the inflow air receives from the pressure surface 3b is orthogonal to the axis of the hub 4 and in the axial direction. A reaction force component is generated, but this reaction force component acts in a direction opposite to the direction of the centrifugal force accompanying the rotation of the impeller 2. Therefore, the centrifugal flow A based on the centrifugal force caused by the rotation of the impeller 2 is generated by the reaction force component.
₀ (see FIG. 13) is suppressed as much as possible, and as shown by the air flow line A in FIG. 12, air sucked in from the vicinity of the leading edge 3c of the blade 3 and the leading edge 3h of the blade outer peripheral edge 3e. It is the centrifugal flow a ₀ without receiving much influence of the deflection action on the blade outer peripheral edge 3e close by, in the case of the conventional blade 33 in comparison with (see Figure 24), as much as possible the flow close to a straight line It will flow to the blade trailing edge 3d side. In other words, of the blade outer peripheral edge 3 e of the blade 3, the range in which air can be sucked in smoothly is smaller than that of the conventional blade 33.
It is to be expanded.

As described above, the fact that air can be smoothly sucked in from a wider range of the blade outer peripheral edge 3e of the blade 3 means that the air is turned to the negative pressure surface 3a side of the outer peripheral portion of the pressure surface 3b. This means that the leakage flow is reduced. Also, high air blowing work can be obtained in the vicinity of the hub 4 on the blade trailing edge 3d side. As a synergistic action of these two, the blade 3 and thus the impeller 2
The aerodynamic performance is improved, and the aerodynamic noise is reduced accordingly.

Further, the thickness gradually decreasing from the maximum thickness portion 3f toward the inner peripheral edge 3g is changed to the inner peripheral edge 3g.
The curved shape of the pressure surface 3b is set so as to increase again in the vicinity of the blade. Therefore, for example, without increasing the thickness of the blade 3 near the inner peripheral edge 3g of the blade, the pressure from the maximum thickness portion 3f remains unchanged. The rigidity of the blade 3 is increased by an increase in the thickness in the vicinity of the blade inner peripheral edge 3g (that is, the continuous portion with the hub 4) as compared with the configuration in which the blade inner peripheral edge is gradually reduced to 3g. Thus, the reliability of the blades 3 in terms of strength and, in turn, the reliability of the blades 2 in terms of strength are improved.

[0105] Such impeller 2 in the embodiment 6 of the sixth embodiment, in the fifth blades 3 of such impellers 2 in embodiment shown in FIG. 12, the pressure surface 3b of the blade 3 as described above Is to specify a region in which is curved. That is, in FIG.
Line Lf set near blade leading edge 3c and blade leading edge 3
The pressure surface 3b is curved as shown in FIG. 13 only in a range surrounded by the region line Lr set closer to c. Further, the leading edge 3c of the blade is larger than the area line Lf.
In the range located closer to the blade, and in the range located closer to the trailing edge 3d of the blade than the area line Lr, the set thickness based on the airfoil blade structure (the portion indicated by the chain line in FIG.
b ')) is kept constant from the maximum thickness portion 3f to the blade inner peripheral edge 3g.

Here, the area line Lf and the area line Lr are
The chord length S at each radius of the blade 3 has the following relationship. In other words, the area line Lf near the blade leading edge 3c is a continuous line of points where the distance from the blade leading edge 3c on the chord length at each radius is "0.2S". The region line Lr near the blade trailing edge 3d is a line in which points at a distance from the blade leading edge 3c on the chord length at each radius are "0.9S".

With such a configuration, the pressure surface 3b
In a region surrounded by the region line Lf and the region line Lr, which is formed by bending, the same operation and effect as those of the third embodiment can be obtained, but it does not have such a curved structure. The following specific effects can be obtained in each of the regions, that is, the region closer to the blade front edge 3c than the region line Lf and the region closer to the blade rear edge 3d than the region line Lr. That is, since the blade 3 has an airfoil blade structure, as shown in FIG. 18, the blade front edge 3c side has a large wall thickness and the blade rear edge 3d side has a small wall thickness. . For this reason, on the blade leading edge 3c side, which is a portion having a large thickness and obtaining the airfoil effect most, the high airfoil effect is achieved by maintaining the thickness without bending the pressure surface 3b. You. Further, in the blade trailing edge 3d whose rigidity is lower than that of the blade leading edge 3c due to its small thickness, the rigidity is maintained by maintaining the thickness without bending the pressure surface 3b. Reduction is prevented. Therefore, as a synergistic effect, it is possible to achieve both the airfoil effect and the strength performance of the blade 3 while reducing the aerodynamic noise of the propeller fan 1.

Seventh Embodiment The impeller 2 according to the seventh embodiment is different from the impeller 2 according to the fifth embodiment shown in FIG. 12 in the pressure surface 3b of the impeller 3 as described above. The position of the maximum thickness portion 3f, which is a reference point when the is curved, is specified on the blade 3. That is, in FIG. 12, the maximum thickness portion 3f is provided in a range surrounded by the blade outer peripheral edge 3e of the blade 3 and the region line La. Note that, as described above, the maximum thickness portion 3f is
This corresponds to the end of the arc surface portion 14 on the pressure surface 3b side in e.

Here, the area line La corresponds to the impeller 2
Is an arc defined by a diameter D = {((D ₀ ² + Dh ² ) / 2) ^0.5 }, where D _{0 is} the outer diameter of D and Dh is the outer diameter of the hub 4. The diameter D corresponds to the average radius of the blades 23 when viewed from the total work amount. Therefore, the portion outside the region line La performs a larger blowing work than the inside portion.

In the impeller 2 of this embodiment, it is needless to say that the same effect as that of the fifth embodiment can be obtained by curving the pressure surface 3b. By setting the position of the maximum thickness portion 3f as described above, the following specific operation and effect can be obtained. That is, by setting the maximum thickness portion 3f of the blade 23 within the outer diameter D ₀ of the diameter D and the impeller 2,
The part that performs the larger air blowing work and the part that provides the highest airfoil effect overlap, and the impeller 2
The aerodynamic performance of the vehicle will be further enhanced.

[0111] impeller 2 according to Embodiment No. 8 of the eighth embodiment is obtained by combining the characteristic configuration of the fifth to seventh embodiment.
That is, the pressure surface 3b of the blade 3 in the third embodiment
Is set in a region surrounded by the region line Lf and the region line Lr specified in the sixth embodiment, and the position of the maximum thickness portion 3f serving as a bending reference point of the pressure surface 3b is determined. This is set within a range surrounded by the diameter D specified in the seventh embodiment and the blade outer peripheral edge 3e of the blade 3.

Therefore, with this configuration, the blade 3
The curved shape on the pressure surface 3b is specified only in a substantially fan-shaped region surrounded by the region lines Lf, the region lines Lr, and the region lines La. In this region, the pressure surface 3b is in the other region. Will be in a state of being depressed. With such a configuration, the same operation and effect as obtained in each of the above embodiments can be obtained at the same time.

[0113] impeller 2 according to a ninth embodiment ninth embodiment, as the chain line shown in FIG. 13, which the blade 3 is made of resin and hollow structure with a cavity 6 therein It is. With this structure, in addition to obtaining the same operation and effect as in each of the above-described embodiments, in addition to the case where the blade 3 has a solid structure, for example, it corresponds to the portion where the hollow portion 6 is formed. The weight of the blade 3 can be reduced by that much, and the required driving power of the impeller 2 can be reduced or the strength performance can be improved accordingly.

The hollow structure of the blade is not limited to the one having the configuration in which the thickness of the blade 3 changes in the radial direction as in this embodiment, but is the same as the blade 3 in the first and second embodiments. It is needless to say that the present invention can be applied to a structure having a thickness that is substantially constant in the radial direction.

Tenth Embodiment FIGS. 14 and 15 show a part of an impeller 2 according to a tenth embodiment. The impeller 2 of this embodiment is obtained by forming the impeller 3 and the hub 4 integrally by press forming a sheet metal, while the impeller 2 of each of the above embodiments uses a resin molded product. . That is, on the outer peripheral side of the hub 4 drawn and formed in a hat shape, a sheet metal portion continuous from the hub 4 is bent into two by bending, and one surface thereof is formed into a substantially flat plate shape. Is a negative pressure surface 3a, and the other surface is
And The pressure surface 3b is connected to the outer peripheral edge 3 of the blade.
e, the straight surface portion 10 and the arc-shaped surface portion 14 are formed in the range from the maximum thickness portion 3f to the maximum thickness portion 3f, and the range from the maximum thickness portion 3f to the hub outer peripheral surface 4a is on the axial center side of the hub 4. It is formed in an arc shape so that the distance from the negative pressure surface 3a gradually decreases toward it. Therefore,
The blade 3 has a hollow airfoil blade structure having a cavity 6 therein.

FIG. 14 shows a structure in which the suction surface 3a of the blade 3 is connected to the hub 4 and one end of the pressure surface 3b is welded and fixed to the suction surface 3a after molding.
15 shows a structure in which the pressure surface 3b side of the blade 3 is connected to the hub 4 and one end of the negative pressure surface 3a is welded and fixed to the pressure surface 3b side after molding. Although the same operation and effect as those of the sheet metal of each embodiment can be obtained, the following specific operation and effect can also be obtained in addition thereto.

That is, the impeller 2 in this embodiment is
Since the blade 3 has a hollow structure formed by press-molding a sheet metal so as to have a hollow portion 6 in the inside of its thickness, while maintaining the low cost characteristic of the sheet metal blade,
A high airfoil effect can be obtained.
Further, since the blades 3 are formed integrally with the hub 4 by press molding of a sheet metal, the cost of the impeller 2 including the blades 3 and the hub 4 is reduced, and the ease of handling of the impeller 2 is improved. Is realized.

The hollow structure of the blade is not limited to the one having the configuration in which the thickness of the blade 3 changes in the radial direction as in this embodiment, but is the same as the blade 3 in the first and second embodiments. It is needless to say that the present invention can be applied to a structure having a thickness that is substantially constant in the radial direction.

[Brief description of the drawings]

FIG. 1 is a front view of a blade of a propeller fan impeller according to the present invention, as viewed from a pressure surface side.

FIG. 2 is an enlarged sectional view taken along the line II-II in FIG.

FIG. 3 is an enlarged sectional view taken along the line III-III in FIG. 1;

FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG.

FIG. 5 is an explanatory diagram of an air flow at a blade outer peripheral edge portion of the blade shown in FIG. 2;

FIG. 6 is an explanatory diagram of an air flow at a blade outer peripheral edge portion of the blade shown in FIG. 3;

FIG. 7 is an explanatory diagram of an air flow at a blade outer peripheral edge portion of the blade shown in FIG. 4;

FIG. 8 is a sectional view showing a modification of the sectional structure of the outer peripheral edge of the blade shown in FIG. 2;

9 is a cross-sectional view showing a modification of the cross-sectional structure of the outer peripheral edge of the blade shown in FIG.

FIG. 10 is a sectional view showing a modification of the sectional structure of the outer peripheral edge of the blade shown in FIG. 4;

FIG. 11 is an explanatory diagram of an air flow in a blade outer peripheral edge portion of the blade shown in FIG. 8;

FIG. 12 is an explanatory view of an air flow on a pressure surface of a blade in a propeller fan impeller according to the present invention.

FIG. 13 is an enlarged sectional view taken along the line XIII-XIII of FIG.

FIG. 14 is a sectional view showing another example of the structure of the blade.

FIG. 15 is a sectional view showing another example of the structure of the blade.

FIG. 16 is a front view of a conventional propeller fan impeller.

FIG. 17 is a sectional view taken along line XVII-XVII of FIG. 16;

FIG. 18 is an enlarged sectional view taken along the line VIII-VIII of FIG.

19 is an enlarged cross-sectional view taken along the line XIX-XIX of FIG.

FIG. 20 is an explanatory diagram of an air flow at a blade outer peripheral edge of a conventional blade.

FIG. 21 is an explanatory diagram of an air flow at a blade outer peripheral edge of a conventional blade.

FIG. 22 is an explanatory diagram of an air flow at a blade outer peripheral edge of a conventional blade.

FIG. 23 is an explanatory diagram of an air flow in a cross section direction in a conventional blade.

FIG. 24 is an explanatory diagram of an air flow in a plane direction in a conventional blade.

[Explanation of symbols]

1 propeller fan, 2 impeller 3 blades, 3a negative pressure surface, 3a ₁ of the suction surface 3a leading edge, 3b pressure surface, 3
c is the leading edge of the blade, 3d is the trailing edge of the blade, 3e is the outer peripheral edge of the blade, 3
f is the maximum thickness, 3g is the inner edge of the blade, 3h is the leading edge, 3i is the trailing edge, 4 is the hub, 5 is the fan guide,
6 is a hollow portion, 10 is a linear surface portion, 11 is a bent surface portion, 12 is a first linear surface, 13 is a second linear surface, 14 is an arc surface portion, 15
Is a linear surface portion, 16 is a bent surface portion, 17 is a first linear surface, 18
Is a second linear surface, 19 is an arc surface portion, 20 is an arc surface, Q is an impeller center, W ₁ is a first region, W ₂ is a second region, and W ₃ is a _third region.
Area.

Claims (16)

[Claims] 1. A propeller fan impeller comprising a plurality of thick blades (3) provided on an outer periphery of a hub (4) at a predetermined pitch in a circumferential direction and arranged inside a fan guide (5). The first region (W) located in the range from the leading edge side end (3h) of the blade outer peripheral edge (3e) of the blade (3) to (2/3) the length of the blade outer peripheral edge (3e). The cross-sectional shape in the vicinity of the outer peripheral edge (3e) of the blade in ( ₁ ) is linearly formed between the suction surface (3a) extending from the leading edge (3a ₁ ) of the suction surface (3a) and the suction surface (3a). A linear surface portion (10) extending linearly toward the pressure surface (3b) side at a predetermined included angle (θa), and the linear surface portion (10) and the pressure surface (3b).
And a substantially wedge-shaped arc surface portion (14) smoothly extending with an arc bulging toward the pressure surface (3b) side. 2. A propeller fan impeller comprising a plurality of thick blades (3) provided at a predetermined pitch in a circumferential direction on an outer periphery of a hub (4) and arranged inside a fan guide (5). The first region (W) located in the range from the leading edge side end (3h) of the blade outer peripheral edge (3e) of the blade (3) to (2/3) the length of the blade outer peripheral edge (3e). The cross-sectional shape in the vicinity of the outer peripheral edge (3e) of the blade in ( ₁ ) is linearly formed between the suction surface (3a) extending from the leading edge (3a ₁ ) of the suction surface (3a) and the suction surface (3a). A first linear surface (12) extending linearly toward the pressure surface (3b) side with a predetermined included angle (θa), and a first linear surface (12) continuous with the first linear surface (12). And a second straight surface (13) forming a bent surface swelling toward the pressure surface (3b). ), And the second linear surface (13) and the pressure surface (3b) of the bent surface portion (11) smoothly continue with an arc bulging toward the pressure surface (3b) side with an arc surface portion (14). An impeller for a propeller fan, wherein the impeller has a substantially wedge shape. 3. A range from a trailing edge (3i) of a blade outer peripheral edge (3e) of the blade (3) to (１ ／) of a length of the blade outer peripheral edge (3e). A negative pressure surface (3a) extending linearly in cross section near the blade outer peripheral edge (3e) in a second region (W ₂ ) not included in the fan guide (5); From the leading edge (3a ₁ ) to the suction surface (3a)
And a linear surface portion (15) extending linearly toward the pressure surface (3b) side with a predetermined included angle (θb) between the pressure surface (3b) and the pressure surface (3b). 3b)
An arc surface part (19) that smoothly continues with an arc bulging to the side
And the included angle (θb) is set to an angle smaller than the included angle (θa) between the negative pressure surface (3a) and the linear surface portion (10) in the first region (W ₁ ). An impeller for a propeller fan, which is set. 4. A range from the trailing edge (3i) of the outer peripheral edge (3e) of the blade (3) to (1/3) the length of the outer peripheral edge (3e) of the blade (3). A negative pressure surface (3a) extending linearly in a cross-sectional shape near the outer peripheral edge (3e) of the blade in a second region (W ₂ ) not included in the fan guide (5); From the leading edge (3a ₁ ) to the suction surface (3a)
And a first linear surface (17) extending linearly toward the pressure surface (3b) side with a predetermined included angle (θb), and the first linear surface (17) being continuous with the first linear surface (17). 17), a second straight surface (18) forming a bent surface bulging toward the pressure surface (3b), and the second surface of the bent surface (16). The linear surface (18) and the pressure surface (3b) have a substantially wedge shape formed by an arc surface portion (19) smoothly bulging toward the pressure surface (3b) and having the arc angle (θb). ) Is set to an angle smaller than the included angle (θa) between the negative pressure surface (3a) in the first region (W ₁ ) and the first straight surface (12) of the bent surface portion (11). Characteristic impeller for propeller fan. 5. The blade according to claim 1, wherein a range from a trailing edge (3i) of the blade outer peripheral edge (3e) of the blade (3) to (１ ／) of a length of the blade outer peripheral edge (3e). A negative pressure surface (3a) extending linearly in cross section near the blade outer peripheral edge (3e) in a second region (W ₂ ) not included in the fan guide (5); From the leading edge (3a ₁ ) to the suction surface (3a)
And a first linear surface (17) extending linearly toward the pressure surface (3b) side with a predetermined included angle (θb), and the first linear surface (17) being continuous with the first linear surface (17). 17), a second straight surface (18) forming a bent surface bulging toward the pressure surface (3b), and the second surface of the bent surface (16). The linear surface (18) and the pressure surface (3b) have a substantially wedge shape formed by an arc surface portion (19) smoothly bulging toward the pressure surface (3b) and having the arc angle (θb). ) Is set to an angle smaller than the included angle (θa) between the negative pressure surface (3a) and the linear surface portion (10) in the first area (W ₁ ). 6. The blade (3) according to claim 2, wherein the outer peripheral edge (3e) of the blade (3) ranges from a trailing edge side end (3i) to (１ ／) of the length of the outer peripheral edge (3e). A negative pressure surface (3a) extending linearly in cross section near the blade outer peripheral edge (3e) in a second region (W ₂ ) not included in the fan guide (5); From the leading edge (3a ₁ ) to the suction surface (3a)
And a linear surface portion (15) extending linearly toward the pressure surface (3b) side with a predetermined included angle (θb) between the pressure surface (3b) and the pressure surface (3b). 3b)
An arc surface part (19) that smoothly continues with an arc bulging to the side
And the included angle (θb) between the negative pressure surface (3a) and the first linear surface (12) of the bent surface portion (11) in the first region (W ₁ ). An impeller for a propeller fan, wherein the angle is set smaller than the included angle (θa). 7. A propeller fan impeller comprising a plurality of thick blades (3) provided at a predetermined pitch in a circumferential direction on an outer periphery of a hub (4) and arranged inside a fan guide (5). The fan guide (5) has a range from the trailing edge (3i) of the blade outer peripheral edge (3e) of the blade (3) to (1/3) the length of the blade outer peripheral edge (3e). The cross-sectional shape of the third region (W ₃ ) in the vicinity of the outer peripheral edge (3e) of the blade is a circular arc surface having the same curvature and continuous with the negative pressure surface (3a) and the pressure surface (3b). 20a),
An impeller for a propeller fan, wherein the impeller has a curved shape provided with an arc surface portion (20) made of (20b). 8. The blade according to claim 1, 2, 3, 4, 5, or 6, wherein a length of the blade outer peripheral edge (3e) from the trailing edge side end (3i) of the blade outer peripheral edge (3e). In the third area (W ₃ ) included in the fan guide (5), the cross-sectional shape near the outer peripheral edge (3e) of the blade having the same curvature and a negative Arc surfaces (20a) continuous with the pressure surface (3a) and the pressure surface (3b),
An impeller for a propeller fan, wherein the impeller has a curved shape provided with an arc surface portion (20) made of (20b). 9. The blade camber length at each radial position of the blade (3) and a blade leading edge on the blade camber according to claim 1, 2, 3, 4, 5, 6, 7, or 8. The thickness of the blade (3) in each curve or straight line (L ₁ ) obtained by connecting points having the same ratio to the distance from 3c) for each ratio is as follows:
The maximum thickness portion (3) in the vicinity of a continuous portion between the arc surface portions (14), (19), (20) and the pressure surface (3b).
The impeller for a propeller fan, wherein the pressure surface (3b) is curved so as to gradually decrease from (f) toward the hub outer peripheral surface (4a). 10. The blade camber length at each radial position of the blade (3) and a blade leading edge on the blade camber according to claim 1, 2, 3, 4, 5, 6, 7, or 8. The thickness of the blade (3) in each curve or straight line (L ₁ ) obtained by connecting points having the same ratio to the distance from 3c) for each ratio is as follows:
The maximum thickness portion (3) in the vicinity of a continuous portion between the arc surface portions (14), (19), (20) and the pressure surface (3b).
f) The pressure surface (3b) of the blade (3) is curved so as to gradually decrease from the outer peripheral surface (4a) to the hub outer peripheral surface (4a) and increase again near the hub outer peripheral surface (4a). Impeller for propeller fan. 11. The range in which the pressure surface (3b) of the blade (3) is curved, according to claim 9 or 10,
With respect to the chord length (S) at each radial position of the blade (3), the distance from the blade leading edge (3c) is set in a range from the position (0.2S) to the position (0.9S). An impeller for a propeller fan. 12. The blade (3) according to claim 9, 10 or 11, wherein the outer diameter of the impeller (2) is (D ₀ ) and the outer diameter of the hub (4) is (Dh). Each curve or straight line (L ₁₎ obtained by connecting points at which the ratio of the length of the blade camber at each radial position to the distance from the blade leading edge (3c) on the blade camber is the same for each ratio ), The position of the maximum thickness portion (3f) of the blade cross section is represented by a diameter D ｛= ((D ₀ ²
+ Dh ² ) / 2) An impeller for a propeller fan, which is set within a range defined by ^0.5 ° and an outer diameter (D ₀ ) of the impeller (2). 13. The blade according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the thickness of the blade (3) is
9) The propeller fan, which is substantially the same from the maximum thickness portion (3f) in the vicinity of the continuous portion between the pressure surface (3b) and the pressure surface (3b) toward the hub outer peripheral surface (4a). Impeller. 14. The method of claim 9, 10, 11, 12, or 13.
The impeller for a propeller fan according to any one of claims 1 to 3, wherein the impeller (3) has a hollow structure having a hollow portion (6) inside its thickness. 15. The method of claim 9, 10, 11, 12, or 13.
3. The impeller for a propeller fan according to claim 1, wherein the blade (3) has a hollow structure formed by pressing a sheet metal so as to have a hollow portion (6) inside its thickness. 16. The propeller fan impeller according to claim 15, wherein the blade (3) is formed integrally with the hub (4) by press-molding a sheet metal.