JP3515437B2 - Cross flow fan and air conditioner using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross flow fan (hereinafter referred to as a cross flow fan) in which a plurality of blades are arranged in a cylindrical shape around a rotation axis, and an air conditioner using the cross flow fan.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner that conditioned indoor air by circulating indoor air through a heat exchanger, a cross-flow fan in which circulating air flows across a fan has been used.

An air conditioner equipped with such a cross flow fan is generally provided with a suction port in the upper part and front cover of its body case, and an air outlet in the lower part of its body case. An air filter, a heat exchanger, and a cross flow fan are sequentially arranged from the windward in a ventilation path connecting the suction port and the air outlet.

FIG. 7 shows such a cross flow fan 100.
FIG. As shown in the figure, the rotary shaft 101 of the cross flow fan 100 is provided with a plurality of support discs 102 at predetermined intervals, and a plurality of blades 103 are provided at the peripheral edge of the support disc 102. There is.

Such a cross flow fan 100 is
It is driven by an electric motor (not shown). At this time, in order to improve the blowing efficiency, the cross flow fan 100 is provided so as to be sandwiched between a rear guider and a stabilizer (not shown). A tongue surface (not shown) is formed at the tip of this stabilizer.

By the way, when the cross-flow fan 100 constructed as described above rotates, the air that has been heat-exchanged by the heat exchanger is blown into the room from the outlet, and at that time, the cross-flow fan is attached to the tongue surface of the stabilizer. A part of the air discharged from 100 collides and is again sucked into the crossflow fan 100, and as a result, a large concentric vortex eccentric to the crossflow fan 100 is formed in the discharge portion of the crossflow fan 100. Will be done.

Then, when each blade 103 cuts this vortex flow, pressure fluctuation occurs and noise is generated. This noise is, for example, a rotating primary sound related to the interval between adjoining blades, and the noise frequency of the rotating primary sound is N for the number of revolutions per second of the fan,
When the number of sheets is 03, the number is N · Z.

For this reason, conventionally, in order to reduce the primary sound of rotation, a structure has been proposed in which the interval between the blades 103 adjacent in the circumferential direction is random.

However, if the intervals of the blades 103 are randomized in this way, the blades 103 having a small capacity on the suction side are provided.
When (blades with a narrow interval) come and the blades 103 with a small capacity also come to the discharge side, the air volume decreases, and conversely, when there is a blade 103 with a large capacity, the opposite phenomenon occurs. Was invited.

As a result, there is a problem that vibration and noise level increase due to the change of the ventilation amount. Therefore, conventionally, the interval between the blades 103, which is considered to be optimal, has been determined by experiments or the like.

[0011]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
It is very difficult to optimize the interval distribution of 03, and even if the rotating primary sound can be reduced, the blade 10
There was a problem that the rotation sound of low frequency (1N to 20N) accompanying the rotation of No. 3 could not be successfully reduced.

Further, particularly when the noise level in the frequency region around 8N becomes high and the noise level in the frequency region around that frequency changes discontinuously, there is a problem that the listener is uncomfortable. Applicants' experiments have confirmed this to occur.

The present invention has been made in view of the above points, and its object is to reduce the noise level due to the primary sound of rotation as in the prior art and to reduce the noise level around 8N on the low frequency side. Another object of the present invention is to provide a cross-flow fan that reduces fluctuations and realizes low noise without giving discomfort to listeners and an air conditioner using the same.

[0014]

DISCLOSURE OF THE INVENTION The present invention is directed to the circumferential direction of the outer circumference of a plurality of support discs arranged at predetermined intervals in the axial direction.
In a cross-flow fan having a large number of blades arranged, the plurality of blades are arranged in a circumferential direction at intervals determined based on a logistic function defined by the following mathematical expression (1). And specifically, the suction port,
A heat exchanger, a cross-flow fan, and a blower outlet are sequentially arranged from the windward side, and the cross-flow fan circulates air in the conditioned chamber via the heat exchanger, so that a heat medium flowing through the heat exchanger is obtained. In the air conditioner that heat-exchanges with the air to air-condition the room to be conditioned, the cross-flow fan has the above configuration.

By using this structure, the noise level due to the rotating primary sound can be reduced, and at the low frequency side,
It is possible to reduce the intensity and fluctuation of the noise level around N.

[0016]

[Equation 4]

The plurality of blades are arranged in the circumferential direction by determining the angular interval P (n) formed by the nth blade and the (n + 1) th blade about the rotation axis by the following mathematical expression (2). Has been done.

[0018]

[Equation 5]

The angular interval P (n) of one of the blades, specifically, the B-th angle, is set so that the total of the angular intervals P (1) to P (B) of all the blades becomes 360 degrees. Interval P (B)
May be adjusted. By using this configuration, the angular intervals of the blades other than P (B) are arranged at the pitch determined by the logistic mapping.

Further, the manufacturing error δP (n) of the angular interval P (n) of the n-th blade may be formed so as to satisfy the following expression (3). By using this configuration, the above-described effects of the present invention are not impaired.

[0021]

[Equation 6]

Specifically, the plurality of blades are sequentially arranged in the direction opposite to the rotation direction of the cross flow fan at intervals determined based on the logistic function.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A cross flow fan according to the present invention and an air conditioner using the same will be described below with reference to the drawings shown below. FIG. 1 is a cross-sectional view of an indoor unit in an air conditioner including a cross flow fan 11 according to an embodiment of the present invention.

In FIG. 1, the upper part of the main body case 1 and the front cover 7 have suction ports 1a, 7 for sucking indoor air.
a is provided, and a blower outlet 1b that blows conditioned air into the room is provided at the bottom of the main body case 1. And
An air filter 6, a heat exchanger 2, and a cross flow fan 11 are sequentially arranged from the windward in a ventilation path 5 that connects the suction port 1a and the air outlet 1b.

The heat exchanger 2 constitutes a condenser or an evaporator of a refrigeration cycle including at least a refrigerant compressor, a condenser, a pressure reducing device, and an evaporator (not shown). When the heat exchanger 2 is acting as a condenser, heating using the condensing action of the refrigerant is possible, and when the heat exchanger 2 is acting as an evaporator, cooling is possible using the evaporating action of the refrigerant. It is a thing. The heat exchanger 2 may be a heat exchanger through which hot water or cold water flows. In this case, heating and cooling can be performed by radiating or cooling the heat exchanger 2.

The cross flow fan 11 is driven by an electric motor (not shown), and is provided so as to be sandwiched between the rear guider 1c and the stabilizer 4 having the tongue surface 4a in order to enhance the blowing efficiency. The rear guider 1c has a shape in which the cross-sectional area of the ventilation passage 5 expands from the position of the crossflow fan 11 toward the rear of the crossflow fan 11 in the ventilation passage 5 toward the outlet 1b. The rib 1d is formed to further improve the blowing efficiency.

The stabilizer 4 also serves as a drain pan (water receiving tray) for receiving drain water flowing down from the heat exchanger 2.

Further, the lowest point of the cross flow fan 11 is set higher than the lowest point of the heat exchanger 2 so that the area of the heat exchanger 2 which acts effectively is increased. That is, with this arrangement, the air that has passed through the lower part of the heat exchanger 2 also crosses the cross flow fan 1
After being sucked into 1, it is blown into the room from the outlet 1b,
The heat exchanger 2 can be used efficiently.

Next, the configuration of the cross flow fan 11 will be described with reference to FIGS. FIG. 2 is a front view of the cross flow fan 11 showing one embodiment of the present invention,
3 is a cross-sectional view of the cross flow fan 11 of FIG. 2 taken along the line AA, and FIG. 4 is an enlarged cross-sectional view of the blade of FIG. 2 in the short side direction.

As shown in FIGS. 2 and 3, in the blades (blades) 12 of the crossflow fan 11 of the present invention, a plurality of support disks 13 are arranged at substantially equal intervals along the rotation axis 14 of the crossflow fan 11. A plurality of blades 12 are provided side by side, and a plurality of blades 12 are provided around the support disk 13 so as to surround the rotary shaft.

A motor (not shown) is connected to one end 14a of the rotary shaft 14 to rotate in the ω direction. The approximate dimensions of the cross flow fan 11 are such that the fan radius D4 is D4 = 88 mm and the axial length L2 is L2 = 600 mm in this embodiment.

Each blade 12 extends along the axis of rotation 14,
In addition, the driven end has a rotation direction ω more than the driven end.
It is provided so as to be inclined so as to go to, forming a so-called skew. In this embodiment, as shown in FIG. 2, the twist angle θ of the blade 12 in the direction of the rotation axis 14 is θ = 43 degrees.

Further, as shown in FIG. 4, the blade 12 is formed in a curved shape in an arc shape. The concave surface is attached to the support disk 13 so that the concave surface faces the rotation direction ω.

In this embodiment, the dimensions of the blade 12 are as follows: chord length L is L = 11.7 mm, back side arc radius R1 is R1 = 9 mm, ventral side arc radius R2 is R2 = 10 mm, back side arc and ventral side arc. The radius R3 of the end arc between and is R3 = 0.44 mm.

The interval between the blades 12 adjacent to each other in the circumferential direction is determined based on the chaos theory. In particular,
When the total number of blades 12 is B and the angle formed by the n-th blade 12 and the n + 1-th blade 12 about the rotation axis 14 is P (n), the logistic defined by the following mathematical expression (4) A chaotic sequence which is a pseudo-random number corresponding to each blade 12 is obtained based on the function, and the chaotic sequence is used to determine the angle according to the following mathematical expression (5). In this embodiment, the total number of blades 12 is B = 35.

[0036]

[Equation 7]

[0037]

[Equation 8]

The blades 12 whose angular intervals (pitch) are determined in this manner are sequentially arranged in the direction opposite to the rotation direction ω side to form the cross flow fan 11.

When the total of the angular intervals P (1) to P (35) of all the blades 12 is not necessarily 360 degrees, for example, the angular interval P (35) of the last blade 12 is set. It may be adjusted so that the total is 360 degrees.

Table 1 shows the values of the angular intervals of the blades 12 determined as described above.

[0041]

[Table 1]

As a result, the angular intervals of the blades other than P (35) are arranged at the angular intervals determined by the logistic mapping.

Next, the results of experiments conducted using the cross-flow fan 11 of the present invention having the above-mentioned structure will be described.

In this experiment, the effect of the present invention was confirmed by comparing with the conventional product in which the angular interval of each blade is set to a random pitch which seems to be optimum in order to reduce the primary sound of rotation (NZ sound). There is.

FIG. 5 is a diagram showing the angular intervals of the cross flow fan 11 according to the conventional product and the structure of the present invention.
Here, the horizontal axis of FIG. 5 is each blade 1 to 35
2 is shown, and the vertical axis shows the angular interval P (n) corresponding to each blade 12.

FIG. 6 shows the noise test results when the cross flow fan 11 set at the angular intervals shown in FIG. 5 is rotated at 1360 rpm. Here, the horizontal axis of FIG. 6 represents frequency (Hz) and the vertical axis represents noise level (dB).

As can be seen from FIG. 6, the rotating primary sound NZ
(= 793 Hz) is 24 dB in the conventional configuration and 2 in the configuration of the present invention.
It is 7 dB, which is slightly higher in the configuration of the present invention, but there is almost no difference. Note that, in FIG. 6, the result of the rotating primary sound when the angular intervals of the blades 12 are set to an equal pitch is shown by x, and the value is 29 dB.

Further, in the case of 8N (= 181 Hz) on the low frequency side, the conventional product has 29 dB, whereas in the configuration of the present invention, it is 1 dB.
The value is 6 dB, which is a very low value, and there is almost no variation in the frequency region before and after that.

From the above, according to the above-mentioned configuration of the present invention, the noise level due to the rotating primary sound is reduced and
It can be seen that the intensity and fluctuation of the noise level around 8N on the low frequency side are reduced. Therefore, unlike the related art, the noise around 8N in the low frequency region does not cause the listener to feel uncomfortable.

Further, the air passing through the lower part of the heat exchanger 2 swirls at the root portion of the tongue surface 4a, and the swirl generated at this root portion is blown out from the cross flow fan 11 and is then passed through the tongue surface 4
Noise increases when synchronized with the swirl generated by hitting a. However, by configuring the crossflow fan 11 at the angular intervals according to the present invention, the noise component is dispersed in a wide band, and the noise level is in a specific region. It is possible to prevent a situation in which the size becomes extremely large.

A manufacturing error occurs when the cross flow fan 11 is manufactured. When the manufacturing error is δP (n), -1.0≤δP (n) ≤1.0 is satisfied. No significant difference was observed in the above-mentioned effects.

In the description of the above embodiment, each blade 1
A case has been described in which the angular interval P (n) of 2 is determined according to the above mathematical expression (4) by obtaining the chaos sequence corresponding to each blade 12 based on the logistic function defined by the above mathematical expression (4). The experimental results for the case of changing the value of the constant A of the logistic function were also performed. Here, the changing range of the constant A was performed when the value of the constant A was 4.0 or less, excluding the case of the constant A> 4.0 where X (n) <0.

As a result of the experiment, when the value of the constant A is set to 3.5 or less, the noise level is 16 dB in the low frequency side 8N as in the case of A = 4.0, and the fluctuation occurs in the frequency region before and after that. Although a small result was obtained, the noise level in NZ was 29 dB. The noise level at this NZ is the same as the noise level at equal pitches, and it can be said that the noise level reduction effect by the rotating primary sound similar to the case of A = 4.0 is not obtained.

On the other hand, when A = 3.6,
In the case of 8N on the low frequency side, the noise level was 16 dB as in the case of A = 4.0, and the result was small in the frequency region before and after that, and the noise level in NZ was also 27.5 dB. Further, even when 3.6 <A, the noise level is 16 dB for 8N on the low frequency side as in the case of A = 4.0, and the result is small in the frequency range before and after that, and NZ
The noise level was 27-27.5 dB.

Thus, the constant A of the logistic function is
Even when the value of is set to 3.6 ≦ A <4.0, the noise level due to the rotating primary sound is reduced and the strength and fluctuation of the noise level around 8N on the low frequency side are reduced as in the case of A = 4.0. Has been reduced.

In the experiment described above, the total number of blades 12 is 35, the skew angle is 43 degrees, and the blades 1 have an angular interval P (1) to P (35) determined based on the chaos theory.
Although the case where 2 is sequentially arranged in the direction opposite to the fan rotation direction ω side has been described, the present invention is not limited to this and similar results can be obtained under other conditions.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. Further, the configuration of each part of the present invention is not limited to the above embodiment,
It goes without saying that various modifications can be made within the technical scope described in the claims.

Also, the method of manufacturing the cross flow fan 11 is not limited to the method of combining one blade 12 with the plurality of support disks 13 as described above, and a plurality of blades are provided around a single support disk. It may be configured by sequentially stacking those having the 12 attached, or may be shaped integrally (or divided into a plurality) with a synthetic resin.

[0059]

As described above, according to the present invention, the noise level due to the rotating primary sound is reduced, and the intensity and fluctuation of the noise level around 8N on the low frequency side are reduced, thereby making listeners uncomfortable. Low noise can be realized without giving.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an indoor unit of an air conditioner using a cross flow fan according to an embodiment of the present invention.

FIG. 2 is a front view of a cross-flow fan showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the cross flow fan 11 of FIG.

4 is an enlarged cross-sectional view of the blade of FIG.

FIG. 5 is a diagram showing an angular interval of a cross-flow fan according to a configuration of the related art and the present invention.

FIG. 6 is a result of noise experiment according to the conventional product having the angular intervals shown in FIG. 5 and the configuration of the present invention.

FIG. 7 is an enlarged perspective view of a main part of a conventional cross-flow fan.

[Explanation of symbols]

1 body case 1a Suction port 1b outlet 1c rear guider 1d rib 2 heat exchanger 4 Stabilizer 4a tongue 5 Ventilation path 6 Air filter 7 Front cover 7a Suction port 11 Cross flow fan 12 feathers 13 Support disk 14 rotation axis

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tomohito Takada 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Yoshinori Toya 2-5 Keihan Hondori, Moriguchi City, Osaka Prefecture 5 Sanyo Denki Co., Ltd. (72) Inventor Kiyoshi Kiyama 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Denki Co., Ltd. (72) Inventor Shigumi Ishigaki 2-5 Keihan Hondori, Moriguchi City, Osaka Prefecture No. 5 within Sanyo Electric Co., Ltd. (56) Reference JP 2000-130388 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F24F 1/00 311

Claims (7)

(57) [Claims] 1. A cross-flow fan having a plurality of blades arranged in a circumferential direction of an outer circumference of a plurality of support disks arranged at a predetermined interval in an axial direction, wherein the plurality of blades are circumferentially expressed by the following formula (1): ) A cross-flow fan characterized by being arranged at intervals determined based on a logistic function defined in (1). [Equation 1] 2. The angular interval P formed by the n-th blade and the (n + 1) -th blade with the rotation axis as a center.
2. The cross flow fan according to claim 1, wherein (n) is determined by the following mathematical expression (2) and is arranged in the circumferential direction. [Equation 2] 3. The angular intervals P (1) to P (B) of all blades
3. The crossflow fan according to claim 2, wherein the angular interval P (n) of any of the blades is adjusted so that the total of the above is 360 degrees. 4. The cross flow fan according to claim 3, wherein the angular interval P (B) of the B-th blade is adjusted. 5. The manufacturing error δP (n) of the angular interval P (n) of the n-th blade is formed so as to satisfy the following mathematical formula (3). Cross flow fan described in crab. [Equation 3] 6. The plurality of blades are sequentially arranged in a direction opposite to the rotation direction of the cross-flow fan at intervals determined based on the logistic function.
The cross-flow fan according to any one of 1 to 5. 7. A suction port, a heat exchanger, a cross-flow fan, and an outlet are sequentially arranged from the windward side, and the cross-flow fan circulates air in the conditioned chamber via the heat exchanger,
An air conditioner that performs heat exchange between a heat medium flowing through the heat exchanger and the air to air-condition the interior of the room to be conditioned, wherein the cross-flow fan is the cross-flow fan according to any one of claims 1 to 6. An air conditioner characterized by being present.