JP3444239B2 - Outdoor unit for air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of grille blades of an air blowout grill portion of an outdoor unit for an air conditioner.

[0002]

2. Description of the Related Art For example, as shown in FIGS. 10 and 11, at present, in many outdoor units for air conditioners, in order to improve the aesthetics (appearance) of the outdoor unit 1, its front side air is used. The structure of the blowout grill 2 includes grille blades 2a, 2a ... Which extend in the left-right direction and support members 2b, 2 which extend in the up-down direction.
It is assumed that it has a lattice shape consisting of b ... And
The grill blades 2a, 2a of the air blowing grill 2 are ...
The cross-sectional shape of is a wing shape having a substantially elliptical cross-section as shown in FIGS. 12 and 13 (see, for example, Japanese Patent Laid-Open No. 5-93531). In FIG. 11, reference numeral 10 is a heat exchanger, and M is a fan motor.

As described above, the grill blades 2a, 2a ...
When the cross-sectional shape of the blade has a wing shape as shown in FIG. 13, the fan guide 41 can be prevented while preventing separation of the airflow at the front edge 3a.
It is possible to suppress to some extent the sound of interference with the flow of air blown from the fan 42 via the fan and the pressure loss and the sound of peeling caused by peeling.

However, in actuality, the blowing air blown from the fan 42 via the fan guide 41 has a strong swirl component associated with the rotation of the fan 42, so that the grill surface of the air blowing grill 2 shown in FIG. In most places, as shown in FIG. 13, for example, the grill blades 2a collide with the air blown from the fan 42 at a predetermined airflow attack angle θa. As a result, due to this, a large separation as shown in FIG. 13 occurs on the negative pressure surface side of the grille blade 2a (the side that is the back surface with respect to the direction of the wind hitting at the predetermined angle θa), which also causes pressure loss and There is a problem that causes peeling noise.

In order to solve such a problem, for example, as shown in FIGS. 14 and 15, in front of the grill blades 2a, 2a, ... Provided on the air blowing grill 2 of the outdoor unit casing 1. It is proposed that the edges 3a, 3a ... Form the serrated portions 5.

As described above, the grill blades 2a, 2a.
.. If the front edges 3a, 3a ... Of the grill blades 2a, 2a ... Have a sawtooth-like structure for the purpose of reducing flow separation on the suction surface side as described above, A large number of small-scale vertical vortices are generated from the valleys 5b, 5b ... Of the groove-like portion 5, and the air flow having a high flow velocity at a position apart from the negative pressure surface of the grill blades 2a, 2a. It becomes possible to draw near the negative pressure surfaces of the grille blades 2a, 2a ..., The flow on the negative pressure surface side of the grille blades 2a, 2a. Less likely to occur.

[0007]

However, even if the saw-toothed portions 5 are provided as described above, if the shape of each saw-toothed portion itself is the same over the entire area of the grill surface, the fan 42 is also required. Grill blades 2a, 2a against the wind blown from
Since the airflow angle of attack θa of ... varies depending on the place, it cannot be a reliable measure for suppressing peeling, and the pressure loss and peeling noise reducing actions are insufficient.

[0008]

The respective inventions of the present application have been made for the purpose of solving the above problems and more effectively reducing pressure loss and peeling noise. It is configured by including an effective problem solving means such as.

(1) The invention according to claim 1, that is, the outdoor unit for an air conditioner according to claim 1 of the present invention is provided with a lattice-shaped air blowing grille 2 of the outdoor unit casing 1 from which air from the fan 42 is blown. grill vanes 2a constituting, 2a ... of the front edge 3a, 3a to form a serrated portion 5 in., the air outlet grille 2 air outlet
Divide the region into multiple regions with different airflow attack angles θa,
Crests 5a of the serration 5, the apex angle θt of 5a · · ·,
The airflow angle of attack θa is different for each of the plurality of regions .

Since the air blown out from the fan 42 has a strong swirling component as described above, the grill has a predetermined airflow attack angle θa which varies depending on the air blowout area of the air blowout grill 2. The blades 2a, 2a, ...
Separation occurs on the negative pressure surface side of a, 2a ... (The side that is the back surface with respect to the direction of the wind hitting at a predetermined angle θa), and causes pressure loss and separation noise.

However, as described above, each grill blade 2
A saw-toothed portion 5 is formed on the front edges 3a, 3a, ... Of the a, 2a ... And the apex angle .theta.t of the peak portions 5a, 5a. When the angle is changed, the peaks 5 of the sawtoothed portion 5 are changed according to the angle θt.
The widths of the valleys 5b, 5b ... Between a, 5a ... Appropriately change, and many vertical vortices of small scale are smoothly generated from the valleys 5b, 5b. , The air flow having a high flow velocity away from the negative pressure surface of the grill blades 2a, 2a ... Can be efficiently attracted to the vicinity of the negative pressure surface of the grill blades 2a, 2a. The flow on the negative pressure surface side of the grille blades 2a, 2a ... Is difficult to separate, and the pressure loss and the separation sound as described above are effectively reduced.

On the other hand, air blow-out with different airflow attack angles θa
Even if we say that the apex angle θt varies depending on the area,
It is difficult to make each grill blade 2a, 2a ... different.
Yes, and the air angle of attack θa between adjacent objects
The difference is not big.

Therefore, the air conditioner of the invention of claim 1 of the present application.
In the outdoor unit, the original airflow angle of attack θa is different.
The air blowing area in the rotation direction is defined, for example, at an airflow attack angle θa.
The sawtooth is divided into multiple areas within a certain difference level range.
The apex angle θt of the peaks 5a, 5a ...
A plurality of areas divided according to the predetermined difference level of the angle θa.
Reasonable by making it different for each area group
Pressure loss and peeling noise as effective as possible
I am trying.

Therefore, according to such a configuration, the low
Cost effective and effective reduction of pressure loss and peeling noise
Will be able to be realized.

(2) Invention of Claim 2 Next, the outdoor unit for an air conditioner of the invention of Claim 2 is the same as that of the invention of Claim 1 above, but in each of the plurality of regions.
S apex angle θt vary depending on the the central axis P in the fan 42
Based on the line XX parallel to the grille blades 2a, 2a ...
As a quasi-direction, a direction symmetrical to each other from the reference line X-X
It is configured to grow larger as it goes away.

According to the invention of claim 1, the air blowing region
Region into multiple regions in different rotation directions with different airflow attack angles θa
Divided according to each of the divided air blowing areas
The apex angle θt of the crests 5a, 5a ...
How to divide the areas if they are made different
Is a problem.

Generally, the airflow attack angle θa is determined by the fan 42.
Passing through the central axis P of the parallel to the grill blades 2a, 2a ...
It gradually becomes smaller as it moves away from the normal position.

Therefore, correspondingly, the apex angle θt
The grille blades 2a passing through the central axis P of the fan 42,
2a ... The line XX parallel to
As the distance from the line
Configured so as to pass through the central axis P of the fan 42,
The distance from the position parallel to the roots 2a, 2a ...
Appropriately respond to the change in the angle of attack θa
Effective pressure loss and reduction of peeling noise within a reasonable range
I am trying.

As a result, the cost is low and the pressure is as effective as possible.
It is possible to realize the effect of reducing loss and peeling noise.
become.

(3) The invention of claim 3 Further, the outdoor unit for an air conditioner of the invention of claim 3 is
In the configuration of the invention of claim 1 or 2, the apex angle θt
Corresponding to the air angle of attack θa, (0.1457θa
^{2 -6.751θa + 90.8) <(θt} ) <(- 0.
1286θa ² −0.2429θa + 126)
Then configured.

The apex angle of the crests 5a, 5a ... Of the serrated portion 5
When θt is set as in the invention of claim 1 or 2,
In the case of
And the apex angle θt is the range of the upper limit value and the lower limit value as described above.
Was effective in.

[0022]

As a result of the above, according to the outdoor unit for an air conditioner of each invention of the present application, the separation of the air flow at each part of the grille blades of the entire air blowing grill is effectively suppressed, and the total pressure loss and the separation noise are suppressed. Can be effectively reduced.

Further , as a result, energy saving performance and silent performance are also improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment) FIGS. 1 to 9 show an air blowing grille portion of an outdoor unit for an air conditioner according to an embodiment of the present invention, and its blade structure and operation.

In FIGS. 1 and 2, reference numeral 1 is an outdoor unit for an air conditioner having an external appearance substantially similar to that of the conventional one described above. In order to improve the appearance, the structure of the front air blowing grill 2 is changed to the left and right grill blades 2a as shown in the drawing.
2a ... and supporting members 2b, 2b. And the grill blade 2
As shown in FIGS. 2 to 7, for example, a is formed so as to have an airfoil structure having a flattened elliptical cross section as compared with a conventional one, and prevents the leading edge from peeling off while the fan guide 4 is removed.
It is possible to suppress the interference sound with the flow of the air blown from the fan 42 via 1 and the pressure loss and the separation sound caused by the separation to be low. Meanwhile, the front edge 3
The a is formed in the serrated portion 5 over the entire longitudinal direction thereof, as shown in FIGS. 2 and 3, for example.

The saw-toothed portion 5 has peak portions 5a, 5a ... As shown in FIGS. 2 and 4 to 7, for example.
Is formed in a rounded surface portion having a predetermined curvature toward the front and back surfaces, while the apex angle θt of the crests 5a, 5a ... Is the air blown from the fan 42 of the air blow grill 2. It is formed to an appropriate value capable of suppressing separation on the suction surface side as much as possible according to the airflow attack angle and the region position in the blowout region.

That is, since the air blown out from the fan 42 has a strong swirl component as described above, as shown in FIG. 13, it is located in the air blowout area of the air blowout grill 2. .., which collide with the grill blades 2a, 2a ... With a predetermined air flow attack angle .theta.a, which causes the grill blades 2a, 2a.
Separation occurs on the negative pressure surface side (the side that is the back surface with respect to the direction of the wind hitting at the predetermined angle θa), causing pressure loss and separation noise.

Therefore, as described above, each grill blade 2
A saw-toothed portion 5 is formed on the front edges 3a, 3a, ... Of the a, 2a ... And the apex angle .theta.t of the peak portions 5a, 5a. When the angle of attack θa is changed so as to have an appropriate value in accordance with different region positions, the sawtooth portion 5 is changed in accordance with the angle θt.
The height H of each mountain portion 5a, 5a ... And each mountain portion 5a,
The width S and depth H of the valleys 5b, 5b ... Between 5a ... Appropriately change, and the valleys 5 of the appropriate width S and depth H are the same.
A large number of small-scale vertical vortices are smoothly generated from b, 5b ..., And the air flow having a high flow velocity at a position apart from the negative pressure surface of the grill blades 2a, 2a. 2a ... can be efficiently attracted to the vicinity of the negative pressure surface, and the grille blades 2a, 2a.
The flow on the negative pressure surface side becomes difficult to separate, and the above-mentioned pressure loss and separation noise are effectively reduced.

However, even if it is said that the apex angle θt is changed according to the area position where the airflow attacking angle θa in the air blowing area is different, all the grill blades 2a, 2a ...
It is difficult to make each of them different, and the airflow attack angle θ between the adjacent grill blades 2a, 2a ...
The difference in a is not large.

Therefore, as described above, the airflow attack angle θa
Different air blowout areas are divided into a plurality of areas within a range of a predetermined different level width, for example, and the mountain portion 5 of the sawtooth portion 5 is divided.
It is possible to make the apex angle θt of a, 5a ... Stepwise different for each of the divided plurality of region groups, thereby achieving effective pressure loss and reduction of peeling noise within a reasonable range. desirable.

By doing so, it becomes possible to realize an effective action of reducing pressure loss and peeling noise at low cost.

On the other hand, in the air blowing grill 2 having the above-mentioned structure, as shown in FIG. 1, the fan 42 is used because of the relationship between the swirling direction of the swirling air flow blown from the fan 42 and the grill blades 2a, 2a. Grill blade 2a passing through the rotation axis P of
A line Y-Y perpendicular to 2a ... divides the air blowing region into two air blowing regions, a left region and a right region, which have different air flow directions. If, for example, the fan 42 is rotating counterclockwise as shown by the arrow in FIG. 1 out of the two left and right air blowing areas, the swirling airflow in the left area is the grill blades 2a, 2a. On the other hand, while it is blown down from the upper side to the lower side, the swirling airflow is blown up from the lower side to the upper side with respect to the grill blades 2a, 2a ... In the right side region. That is,
The direction of the airflow attack angle θa is different.

On the other hand, the air blowing region passes through the central axis P of the fan 42, and the grille blades 2a, 2a ...
Can be divided into two regions, an upper region and a lower region, centered on a line XX parallel to, and these two regions are separated from each other in the upper and lower symmetrical directions about the line XX. Accordingly, the airflow attack angle θa becomes smaller.

Therefore, the above-mentioned air blow-out areas including the above-mentioned blow-up and blow-down areas are indicated by A, B, C, and
When divided into 6 areas D, E, and F, the airflow direction and angle of attack θa are shown in FIG. 4 in the areas A and C, in FIG. 5 in the areas B, in FIG. 6, in the areas D, F, and in the area E. 7, the airflow angle of attack θa seen from the side of the grille blades 2a, 2a ... Is the largest in the B and E regions and is small in the A and F regions and the C and D regions.

Therefore, the apex angle θt is appropriately changed as described above in correspondence with each of the plurality of areas A to F. In that case, the areas B, E, A, F, C, D are each different. The apex angle θt set according to
Line parallel to the grille blades 2a, 2a ...
Is set as a reference, and becomes larger as the distance from the reference line XX in a mutually symmetrical direction is increased, and effective pressure loss and peeling noise are reduced.

By doing so, it is possible to realize an effective action of reducing pressure loss and peeling noise at low cost.

In order to confirm the above effects, the apex angle θt of the above-mentioned peaks 5a, 5a ... Of the grill blade 2a is, for example, 15 °, 30 °, 60 °, 90 °, 1
Five types of grill blade samples of 20 ° were prepared, and the lift / drag coefficient (CL / CD) of each of them showed a small pressure loss at 5 ° intervals in the range of airflow attack angle θa = 0 ° to 25 °.
Was measured and the difference between them and the lift / drag coefficient (CL / CD) of the grille blade (θt = 180 °) in which the sawtooth portion 5 was not formed was calculated. Then, based on the result of FIG. 8, it was found that when the effective range of the apex angle θt corresponding to the airflow attack angle θa was determined, the result was as shown in FIG. 9.

This result shows that the upper limit value is θt = -0.1.
286θa ² −0.2429θa + 126, and its lower limit is θt = 0.1457θa ²
It can be approximated by −6.751θa + 90.8.

Therefore, the apex angle θt is in the range of the upper limit value and the lower limit value (0.1457θa ² -6.7) as described above.
51θa + 90.8) <(θt) <(-0.1286θ
a ² −0.2429θa + 126) and it is judged to be effective.

Therefore, based on these data, for example, a region having a different airflow attack angle θa is divided into a plurality of regions within the range of the predetermined difference level (for example, 0 to 10 as an example).
°, 11-15 °, 16-20 °, 21-25 °, 25
~ 30 °, etc.) and the optimum apex angle θt suitable for each of these regions
It is apparent that the pressure loss and the peeling noise can be effectively reduced as described above by setting

In the above case, it goes without saying that the sawtooth portion 5 is formed in consideration of the chord length L of the grill blades 2a, 2a.

[Brief description of drawings]

FIG. 1 is a front view showing the structure of an outdoor unit for an air conditioner according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a grille blade portion of the outdoor unit.

FIG. 3 is an enlarged plan view showing a detailed structure of a grille blade portion of the outdoor unit.

FIG. 4 is a cross-sectional view (A-A in FIG. 3) taken along the lines A and C in FIG. 1 of the grill blade.

5 is a cross-sectional view (A-A in FIG. 3) of the grille blade at D and F portions in FIG. 1.

FIG. 6 is a cross-sectional view (A-A in FIG. 3) of a portion B in FIG. 1 of the grill blade.

FIG. 7 is a cross-sectional view (A-A in FIG. 3) of a portion C in FIG. 1 of the grill blade.

FIG. 8 is a characteristic diagram showing a difference in lift / drag coefficient CL / CD for each predetermined airflow attack angle θa of a sample example in which the apex angles of the grill blades are different from a conventional case without a serrated portion.

FIG. 9 is a characteristic diagram showing a range of an effective apex angle θt of a mountain portion of a serrated portion with respect to an airflow attack angle θa of the grill blade.

FIG. 10 is a front view showing a structure of a conventional air conditioner outdoor unit and an air blowing grille portion thereof.

FIG. 11 is a cross-sectional view of the outdoor unit and an air blowing grille portion.

FIG. 12 is a plan view of grille blades in an air blowing grille portion of the outdoor unit.

FIG. 13 is a cross-sectional view (BB of FIG. 12) of the grill blade.

FIG. 14 is a plan view of an improved example of the conventional example.

FIG. 15 is a sectional view taken along line CC of FIG.

[Explanation of symbols]

1 is an outdoor unit for an air conditioner, 2 is an air blowing grille, 2a is a grill blade, 3a is a front edge portion, 3b is a rear edge portion, 5 is a serrated portion, 5a is a mountain portion, and 5b is a valley portion.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-10-281499 (JP, A) JP-A-55-7982 (JP, A) JP-A-11-153342 (JP, A) JP-A-10- 176847 (JP, A) Actual development Sho 57-40693 (JP, U) European patent application publication 711925 (EP, A 1) French patent application publication 2277257 (FR, A 1) (58) Fields investigated (Int.Cl . ⁷ , DB name) F24F 5/00 F24F 13/08

Claims (3)

(57) [Claims] 1. The air from a fan (42) is blown out.
That the outdoor unit lattice grill vanes (2a) constituting the air outlet grille (2) of the casing (1), (2a) · · ·
Are formed on the front edges (3a), (3a), ... Of the sawtooth , and the air blowing region of the air blowing grille (2) is formed.
Area is divided into multiple areas with different airflow attack angles (θa)
And, the serrations ridges of (5) (5a), ( 5a) ··
・ The apex angle (θt ) is different from the airflow attack angle (θa)
An outdoor unit for an air conditioner, which is different according to each of a plurality of areas . 2. An apex angle that differs depending on each of the plurality of regions
(Θt) is the amount of grease passing through the central axis (P) of the fan (42).
Line (XX) parallel to the blades (2a), (2a) ...
With respect to the reference line (X-X),
It is configured to grow as it moves away in the nominal direction
The outdoor unit for an air conditioner according to claim 1, wherein the outdoor unit is an air conditioner. 3. The apex angle (θt) is changed to the airflow attack angle (θa).
Correspondingly, (0.1457θa ² −6.751θa + 90.8) <
(Θt) <(− 0.1286θa ² −0.2429θa
The range of +126) is set, The outdoor unit for air conditioners of Claim 1 or 2 characterized by the above-mentioned.