JP2000345995A - Fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a separation range in the blade negative pressure side of a fan for reducing blowing noise and improving blowing efficiency. SOLUTION: In this fan, which is rotated by a prescribed driving means and provided with blades 3, 3, 3 wherein pressure surfaces 3d, 3d, 3d and suction surfaces 3c, 3c, 3c are formed when driving, longitudinal vortex generation parts 4, 4, 4 generating longitudinal vortexes are formed in the direction of back edge parts 3b, 3b, 3b of the suction surfaces 3c, 3c, 3c of the blades 3, 3, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan blade structure.

[0002]

2. Description of the Related Art In an outdoor unit for an air conditioner, for example, a fan 1 such as a propeller fan as shown in FIG.

The fan 1 has a plurality of blades 3, 3, 3 on an outer peripheral surface of a cylindrical hub 2 fixed to a drive shaft of a fan motor via a boss (not shown) provided inside a central portion.
At a predetermined blade angle.

[0004]

The blades 3, 3, 3 of such a fan are generally formed in a shape as shown in FIG. 12, and the air flow is separated particularly near the trailing edge 3b on the negative pressure surface 3c side. Therefore, there is a problem that the blowing noise is generated at the time of rotation and the blowing efficiency is low.

[0005] The present invention has been made to solve such a problem, and an object of the present invention is to provide a fan which prevents the separation of the air flow to reduce the blowing noise and improve the blowing efficiency. Things.

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention is provided with the following means for solving the problems.

(1) The fan of the present invention is rotationally driven by a predetermined driving means, and at the time of driving, the blades 3 on which the pressure surfaces 3d, 3d, 3d and the suction surfaces 3c, 3c, 3c are formed. , 3,3, the suction surface 3c,
The vertical vortex generators 4, 4, 4 for generating vertical vortices in the direction of the trailing edges 3 b, 3 b, 3 b are provided on 3 c, 3 c.

Therefore, in the fan having the above configuration, during rotation, the vertical vortex generators 4, 4, 4 move from the rear edge 3b,
Vertical vortices are generated in the directions 3b, 3b, and the vertical vortices act to bring high-velocity airflows away from the blade suction surfaces 3c, 3c, 3c closer to the suction surfaces 3c, 3c, 3c. The amount of separation of the airflow in the vicinity of the trailing edges 3b, 3b, 3b of the pressure surfaces 3c, 3c, 3c is reduced, the blowing noise is reduced, and the blowing efficiency is improved.

(2) The fan according to the second aspect of the present invention is the fan according to the first aspect of the present invention, wherein the vertical vortex generators 4, 4, 4 are arranged such that the top d side is the front edge 3
A plurality of triangular pyramid-shaped projections 4a, 4a,... are arranged side by side from the hub side to the chip side in a state shifted toward the a side. .

Therefore, the vertical vortex generators 4, 4, having the above-described configuration are provided.
4, effective vertical vortices are generated on both the left and right sides of each of the projections 4a, 4a,... From the upper side to the lower blade negative pressure surface in the direction from the airflow upstream side to the downstream side. The vertical vortex acts so as to bring the airflow having a high flow velocity in a region away from the blade suction surfaces 3c, 3c, 3c close to the suction surfaces 3c, 3c, 3c, and the trailing edge of the suction surfaces 3c, 3c, 3c 3
b, 3b, the amount of airflow separation near the 3b is reduced, the blowing noise is reduced, and the blowing efficiency is improved.

(3) The fan according to the third aspect of the present invention is the fan according to the first or second aspect of the present invention, wherein the vertical vortex generators 4, 4, 4 are located slightly upstream of the separation area. It is characterized by being provided.

The flow on the side of the blade negative pressure surfaces 3c, 3c, 3c flows from the blade leading edges 3a, 3a, 3a to the trailing edges 3b, 3b.
The boundary layer of the flow gradually expands toward the b, 3b side direction, and a separation region is formed from a portion near the trailing edge portions 3b, 3b, 3b.

Therefore, the above-mentioned vertical vortex generators 4, 4, 4 are provided slightly upstream of the separation area. Then, at the position, the boundary layer to be expanded is destroyed and reduced, the separation area is reduced, and the generated vertical vortex is
Since the airflow on the downstream side is attracted to the blade surface side, the amount of separation can be reduced more effectively.

As a result, the blowing noise can be reduced more effectively and the blowing efficiency can be improved.

(4) The fan according to the fourth aspect of the present invention is the fan according to the second or third aspect of the invention, wherein the plurality of triangular pyramid-shaped projections 4a, 4a.
. Are characterized by being arranged side by side while maintaining a predetermined empty space between each other.

It is preferable that longitudinal vortices generated on both sides of each of the projections 4a, 4a... Do not interfere with each other. Therefore, as described above, a predetermined empty space is provided between them, so that the generated vertical vortex acts as effectively as possible to the trailing edge 3b side without being canceled by mutual interference. .

(5) The fan according to the fifth aspect of the present invention is the fan according to the fourth aspect of the present invention, wherein the plurality of triangular pyramid-shaped projections 4a, 4a,. A plurality of rows 4, 4 are provided at predetermined intervals before and after the rotation direction of the wings 3, 3, 3.

As described above, each triangular pyramid-shaped projection 4
The longitudinal vortices generated on both sides of a, 4a,... also gradually attenuate toward the downstream side, such as in a wing structure having a long chord length.

Therefore, a plurality of rows are provided at predetermined intervals before and after the blades 3, 3, and 3 in the rotation direction, and the trailing edge portions 3b,
The vertical vortex is reliably applied to 3b and 3b.

(6) The invention according to claim 6 is a fan according to the invention according to claim 4 or 5, wherein a plurality of rows of the fans are provided in a plurality of rows before and after in the rotational direction of the blades 3, 3, and 3. Triangular pyramid shaped projections 4a, 4a ...
.., 4a, 4a,.
Are arranged between the plurality of protrusions 4a, 4a... On the front row side.

It is preferable that the vertical vortex formed by the front row side projections 4a, 4a... And the vertical vortex formed by the rear row side projections 4a, 4a. .

Therefore, the rear row side projections 4a, 4a,.
Are arranged in a staggered manner so as to be located between the front row-side projections 4a, 4a,... So that each vertical vortex acts effectively as far as possible to the most downstream side.

[0023]

As described above, according to the fans of the present invention, it is possible to provide a blower with low blow noise and high blow efficiency in any of the fans.

[0024]

(Embodiment 1) First, FIGS.
1 shows the whole fan and the configuration of each part according to the first embodiment of the present invention.

FIG. 1 shows an overall configuration of a fan portion when a propeller fan 1 is employed as a fan. In FIG. 1, reference numeral 2 denotes a hub, 3 denotes a wing, 3a denotes a leading edge of the wing 3, 3b denotes a trailing edge of the wing 3, and the wing 3 has a sectional structure as shown in FIG. -B section). If the fan 1 is driven to rotate in the direction of the dashed line in FIG. 1, for example, a pressure surface 3d and a suction surface 3c are formed on the blade 3 and the airflow flowing as indicated by the arrow in FIG. In the conventional case, the trailing edge 3b on the negative pressure surface 3c side
A peeling area is generated over a wide area on the side (see FIG. 12 described above).

However, in the case of the present embodiment, as shown in the drawing, the suction surfaces 3c, 3c, 3c of the blades 3, 3, 3 are shown.
Are provided with vertical vortex generators 4, 4, 4 for generating vertical vortices in the direction of the trailing edges 3b, 3b, 3b.

Therefore, in the propeller fan 1 having the above configuration, during the rotation, the vertical vortex as shown in FIG. 2 is generated from the vertical vortex generators 4, 4, 4 toward the trailing edges 3b, 3b, 3b. The vertical vortex is generated, and the airflow having a high flow velocity in a region away from the blade suction surfaces 3c, 3c, 3c is generated by the blade suction surfaces 3c, 3c.
c, 3c so that the blade suction surfaces 3c, 3c
The amount of separation of the airflow in the vicinity of the trailing edges 3b, 3b, 3b of c, 3c is greatly reduced, and the blowing noise is reduced and the blowing efficiency is improved.

Further, as shown in FIGS. 3 and 4, the vertical vortex generators 4, 4, 4 have their tops d facing the front edge 3 as shown in FIG.
A plurality of triangular pyramid-shaped projections 4a, 4a,... arranged side by side from the hub 2 side to the chip side in a state approaching the a, 3a side.

Therefore, the longitudinal vortex generators 4, 4 and 4 are arranged side by side from the hub 2 side to the chip side, and the top d is
Each of the triangular pyramid-shaped projections 4a, 4a,.
Side from the upper side to the lower side, and from the upper side to the lower side negative pressure surface 3 on the left and right both sides (a, d, c surfaces and a, d, b surfaces)
c, 3c, 3c, an effective longitudinal vortex that tries to wrap around is generated, and the longitudinal vortex is generated by the blade suction surfaces 3c, 3c,
The airflow having a high flow velocity in a region distant from the suction surfaces 3c, 3c
c, 3c so that the suction surfaces 3c, 3c,
3c, the amount of air separation near the trailing edges 3b, 3b, 3b is reduced, and the blowing noise is more effectively reduced and the blowing efficiency is improved (see FIG. 3).

In this case, the triangular pyramid-shaped projection 4 is used.
The vertical vortex generators 4, 4, 4 composed of a, 4a,... are provided slightly upstream of the separation area (start area) on the trailing edge 3b, 3b, 3b side.

Generally, the flow on the side of the blade negative pressure surfaces 3c, 3c, 3c flows from the blade leading edges 3a, 3a, 3a to the trailing edges 3b, 3b.
The boundary layer of the flow gradually expands toward the sides 3b, 3b, and a separation region is formed from a portion near the trailing edges 3b, 3b, 3b.

Therefore, the vertical vortex generator 4, having the above-described structure, is located slightly upstream of the separation area generated in this manner.
4 and 4 are provided. Then, the boundary layer to be expanded is effectively destroyed and reduced at the position, the separation area is reduced, and the generated vertical vortex further reduces the airflow on the downstream side to the blade negative pressure surfaces 3c, 3c, 3c. Since it is attracted to the 3c side, the amount of peeling can be reduced more effectively.

As a result, it is possible to more effectively reduce the blowing noise and improve the blowing efficiency.

The shape and size of the protrusion 4a in FIG. 4 are determined by the ratio L / W of the vertical dimension L from upstream to downstream of the blade installation surface abc and the dimension W between the downstream ends bc, and the airflow angle of attack. By appropriately setting θ or the dimension h between the upstream ends ad, the setting is made so that the above-described action can be obtained as effectively as possible.

(Embodiment 2) FIG. 5 shows a configuration of a fan according to Embodiment 2 of the present invention.

In this embodiment, the triangular pyramid-shaped projections 4a, 4a,... , 3 are arranged in accordance with the degree of advance of the front edges 3a, 3a, 3a.

The other structure is exactly the same as that of the first embodiment.

In this manner, the triangular pyramid-shaped projections 4a, 4a correspond to the starting points of the separation areas which differ depending on the blade shape.
a ... can be effectively and appropriately arranged.

(Embodiment 3) Next, FIG. 6 shows a configuration of a fan according to Embodiment 3 of the present invention.

In the present embodiment, the triangular pyramid-shaped projections 4a, 4a,... It is characterized by being installed side by side while keeping empty space.

It is preferable that longitudinal vortices generated on both sides of each of the triangular pyramid-shaped projections 4a, 4a... Do not interfere with each other. Therefore, as described above, a predetermined empty space is provided between them, and the generated vertical vortex is not canceled out by mutual interference, and the trailing edge 3
It works effectively up to the b side.

(Embodiment 4) FIG. 7 shows a configuration of a fan according to Embodiment 4 of the present invention.

In this embodiment, first, the vertical vortex generators 4, 4, and 4 having the same configuration as that of the third embodiment are arranged at predetermined intervals before and after the rotation direction of the blades 3, 3, and 3. A plurality of columns are provided.

As described above, each triangular pyramid-shaped projection 4
The longitudinal vortices generated on both sides of a, 4a,... also gradually attenuate toward the downstream side, such as in a wing structure having a long chord length.

Therefore, if a plurality of rows are provided at predetermined intervals before and after the rotation direction of the wings 3, 3, 3,
Longitudinal vortices can be reliably applied to the wing trailing edges 3b, 3b, 3b.

Moreover, in such a configuration, in such a case, triangular pyramid-shaped projections 4a, 4a,..., 4a, 4a,.
Are arranged in a staggered manner such that the rear row side projections 4a, 4a,... Are located between the front row side projections 4a, 4a,.

It is preferable that the vertical vortex formed by the front row side projections 4a, 4a... And the vertical vortex formed by the rear row side projections 4a, 4a. .

For this reason, the rear row side projections 4a, 4a,.
Are arranged in the zigzag ground so as to be located between the protrusions 4a, 4a,... In the front row, so that each vertical vortex acts effectively as far as possible to the most downstream side.

In this case, if possible, it is preferable to increase the space between them, as shown in FIG.

(Embodiment 5) FIG. 9 shows a configuration of a fan according to Embodiment 5 of the present invention.

In this embodiment, for example, the blades 3, 3, 3, 3 of the mixed flow fan 10 are provided with the same vertical vortex generators 4, 4, 4 as those of the above embodiments. It is characterized by the following.

In this way, even with the mixed flow fan 10 as shown in the drawing, the same operation and effect as those of the above-described embodiments can be obtained, and the mixed flow with low blowing noise and high blowing efficiency can be obtained. A fan composed of fans can be provided.

(Embodiment 6) Next, FIG. 10 shows a configuration of a fan according to Embodiment 6 of the present invention.

In this embodiment, the vertical vortex generators 4, 4, 4 having the same configuration as those of the above embodiments are applied to the rotor blade 8 of the turbofan 20 instead of the propeller fan 1. It is characterized by the following.

In the figure, reference numeral 6 denotes a fan guide of the turbo fan 20, 6a denotes an air inlet thereof, 6b denotes an air outlet thereof, 7 denotes a shroud, 9 denotes a main plate, and 8 denotes air blowing between the shroud 7 and the main plate 9. A rotor blade provided in the passage 7b, 8a is a leading edge of the rotor blade 8, 8b is a trailing edge of the rotor blade 8, and 7a is an air inlet. In the case of the turbofan 20 having this configuration, the airflow is sucked in the direction of the axis OO ′ through the fan guide 6 as shown in the drawing, and then blown out in the centrifugal direction through the moving blade 8. A pressure surface (back surface in the drawing) and a suction surface 8c are also formed in the portion 8, and a separation area similar to that of the propeller fan described above is generated on the suction surface 8c side.

Therefore, as shown, a vertical vortex generator 4 similar to that of each of the above embodiments is provided slightly upstream of the separation area. By doing so, it is possible to obtain the same operation and effect as in the above-described case, reduce the blowing noise, and improve the blowing efficiency.

(Embodiment 7) In the above-described embodiments 1-4, the case where the present invention is applied to a thin blade fan has been described. However, this is applicable to a fan having a thick airfoil blade structure. Needless to say, it may be applied.

In this case, the fan having an airfoil wing structure may have a hollow interior or a non-hollow interior.

[Brief description of the drawings]

FIG. 1 is a front view showing an overall configuration of a fan according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is a plan view showing an operation of a vertical vortex generator of the fan.

FIG. 4 is a perspective view showing a shape of a main part of the vertical vortex generator.

FIG. 5 is a front view showing an overall configuration of a fan according to Embodiment 2 of the present invention.

FIG. 6 is a front view showing a configuration of a wing portion of a fan according to Embodiment 3 of the present invention.

FIG. 7 is a front view showing a configuration of a wing portion of a fan according to Embodiment 4 of the present invention.

FIG. 8 is a front view of a modification of the fan.

FIG. 9 is a front view showing an overall configuration of a fan according to Embodiment 5 of the present invention.

FIG. 10 is a cross-sectional view showing an overall configuration of a fan according to Embodiment 6 of the present invention.

FIG. 11 is a front view showing the overall configuration of a conventional fan.

FIG. 12 is a sectional view taken along line AA of FIG. 11;

[Explanation of symbols]

2 is a hub, 3 is a wing, 3a is a leading edge, 3b is a trailing edge, 3c
Is a suction surface, 3d is a pressure surface, 8 is a moving blade, 8a is a leading edge portion, 8
b is a trailing edge.

Claims (6)

[Claims] 1. A rotary drive by a predetermined drive means,
The wings (3), (3), (3) are provided with the pressure surfaces (3d), (3d), (3d) and the suction surfaces (3c), (3c), (3c) formed during the driving. In the fan (1), the suction surface (3) of the blades (3), (3), (3)
c), (3c), and (3c) at the trailing edge (3b), (3
A fan provided with vertical vortex generators (4), (4) and (4) for generating vertical vortices in the directions (b) and (3b). 2. The vertical vortex generator (4), (4), (4).
Are composed of a plurality of triangular pyramid-shaped projections (4a), (4a)... Arranged in parallel from the hub side to the chip side with the top (d) side approaching the front edge (3a) side. The fan according to claim 1, wherein: 3. The vertical vortex generator (4), (4), (4).
The fan according to claim 1, wherein the fan is provided at a position slightly upstream of the peeling area. 4. The plurality of triangular pyramid-shaped projections (4).
4. The fan according to claim 2, wherein a), (4a),... are arranged side by side while maintaining a predetermined empty space therebetween. 5. The plurality of triangular pyramid-shaped projections (4).
a), a vertical vortex generator (4) composed of (4a) ...
5. The fan according to claim 4, wherein a plurality of rows of (4) and (4) are provided at predetermined intervals before and after the rotation direction of the blades (3), (3) and (3). 6. A plurality of triangular pyramid-shaped projections (4a), (4a),..., (4a) provided in a plurality of rows before and after the rotation direction of the wings (3), (3), (3). ), (4a) ...
Are arranged such that the plurality of projections (4a), (4a)... In the rear row are located between the plurality of projections (4a), (4a). The fan according to claim 4 or 5, wherein: