JP3054616B2 - 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) having a plurality of blades arranged in a cylindrical shape around a rotation axis, and an air conditioner using the same.

[0002]

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

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

FIG. 7 shows such a cross flow fan 100.
It is a perspective view of. As shown in the figure, a plurality of support disks 102 are provided at predetermined intervals on a rotating shaft 101 of a cross flow fan 100, and a plurality of blades 103 are provided at a peripheral portion of the support disk 102. I have.

[0005] Such a cross-flow fan 100 includes:
It is driven by an electric motor (not shown). At this time, in order to increase 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 the stabilizer.

When the cross-flow fan 100 thus configured rotates, the heat exchanged by the heat exchanger is blown into the room from the air outlet. At this time, the cross-flow fan is attached to the tongue surface of the stabilizer. Part of the air discharged from the cross flow 100 collides and is sucked into the cross flow fan 100 again. As a result, a large concentric vortex eccentric to the cross flow fan 100 is formed at the discharge portion of the cross flow fan 100. Will be done.

[0007] When each of the blades 103 cuts off the vortex, pressure fluctuations are generated and noise is generated. This noise is a primary rotation sound or the like related to the adjacent interval of the blades. The noise frequency of the rotation primary sound is N per revolution of the fan, N
When the number Z is 03, NZ is obtained.

For this reason, conventionally, in order to reduce the rotational primary sound, a configuration has been proposed in which the intervals between circumferentially adjacent blades 103 are random.

However, when the intervals between the blades 103 are randomized in this manner, the blades 103 having a small capacity are provided on the suction side.
When the blades (narrow intervals) come and the blades 103 with small capacity come to the discharge side, the air volume decreases. On the contrary, when the blades 103 with large capacity come, the opposite phenomenon occurs. Was invited.

As a result, there is a problem that the vibration and the noise level increase due to the change in 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]

However, the blade 1
03 is very difficult to optimize, and even if the above-mentioned rotating primary sound can be reduced, the blade 10
There is a problem that the low frequency (1N to 20N) rotation sound accompanying the rotation of No. 3 cannot be reduced well.

Furthermore, when the noise level in the frequency region around 8N becomes high, and the noise level in the frequency region before and after that changes discontinuously, there is a problem that the listener is uncomfortable. This has been confirmed in our experiments.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to reduce the noise level due to the rotating primary sound in the same manner 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 realizes low noise without causing discomfort to a listener, and an air conditioner using the same.

[0014]

According to the present invention, a plurality of support disks arranged at a predetermined interval in the axial direction are provided in a circumferential direction of an outer periphery.
In a cross flow fan having a large number of blades, the large number of the blades are circumferentially arranged at intervals determined based on a logistic function defined by the following equation (1). And specifically, the suction port,
A heat exchanger, a cross flow fan, and an outlet are sequentially arranged from the windward, and the cross flow fan circulates the air in the conditioned room through the heat exchanger, thereby forming a heat medium flowing through the heat exchanger. In the air conditioner that exchanges heat with the air to perform air conditioning in the conditioned room, the cross flow fan has the above-described configuration.

(Equation 4)

By using this configuration, the noise level due to the rotating primary sound can be reduced and the low frequency side noise can be reduced.
The intensity and fluctuation of the noise level before and after N can be reduced.

The plurality of blades are arranged in the circumferential direction by determining an angular interval P (n) between the n-th blade and the (n + 1) -th blade with respect to the rotation axis by the following equation (2). Have been.

[0017]

(Equation 5) Then, the angular interval P of any one of the blades is set so that the sum of the angular intervals P (1) to P (B) of all the blades becomes 360 degrees.
(n), more specifically, a configuration in which the B-th angular interval P (B) is adjusted. By using this configuration, P (B)
The other angular intervals of the blades are arranged at a pitch determined based on a logistic function.

Further, the angle intervals P (1) to P
The angle interval P (n) may be adjusted to P ′ (n) determined by the following equation (3) so that the sum of (B) becomes 360 degrees. By using this configuration, all the blades are arranged in a well-balanced manner at the pitch determined based on the logistic function.

[0019]

(Equation 6) Further, the manufacturing error δP of the angular interval P (n) of the n-th blade
(n) may be configured to satisfy −1.0 ≦ δP (n) ≦ 1.0. By using this configuration, the operation and effect of the present invention described above are not impaired.

More 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 a logistic function.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cross flow fan and an air conditioner using the same according to the present invention will be described below with reference to the drawings. FIG. 1 is a 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, suction ports 1a, 7 for sucking room air are provided in an upper portion of a main body case 1 and a front cover 7.
a, and an outlet 1b for blowing conditioned air into the room is provided at a lower portion 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 an air passage 5 connecting the suction port 1a and the air outlet 1b.

The heat exchanger 2 constitutes a condenser or an evaporator of a refrigeration cycle comprising at least a refrigerant compressor, a condenser, a decompression device, and an evaporator (not shown). When the heat exchanger 2 is operating as a condenser, heating using the condensing action of the refrigerant is possible, and when the heat exchanger 2 is operating as an evaporator, cooling using the evaporating action of the refrigerant is possible. Things. The heat exchanger 2 may be constituted by a heat exchanger through which hot 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 increase the blowing efficiency. The rear guider 1c has a shape in which the cross-sectional area of the ventilation path 5 increases from the position of the cross flow fan 11 toward the blowout port 1b at a position corresponding to the rear of the cross flow fan 11 of the ventilation path 5, and The rib 1d is formed to further improve the blowing efficiency.

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

The lowermost point of the cross flow fan 11 is higher than the lowermost point of the heat exchanger 2 to increase the effective area of the heat exchanger 2. That is, the air that has passed through the lower part of the heat exchanger 2 by this arrangement also
After being sucked into the air outlet 1, the air is blown into the room from the air 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 a cross flow fan 11 showing one embodiment of the present invention,
FIG. 3 is a cross-sectional view of the cross flow fan 11 of FIG. 2 taken along the line AA. FIG. 4 is an enlarged cross-sectional view of the blade of FIG.

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

A motor (not shown) is connected to one end 14a of the rotating shaft 14 so as to rotate in the direction of ω. In this embodiment, 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.

Each blade 12 extends along a rotation axis 14,
In addition, the driven-side end is more rotationally ω than the drive-side end.
To form a so-called skew. In this embodiment, as shown in FIG. 2, the torsion angle θ of the blade 12 in the direction of the rotation shaft 14 is set to θ = 43 degrees.

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

In the present embodiment, the dimensions of the blades 12 are as follows: chord length L = 11.7 mm, backside radius R1 = R1 = 9 mm, ventral side radius R2 = R2 = 10 mm, rear side arc and ventral side arc Is set to R3 = 0.44 mm.

The distance between the circumferentially adjacent blades 12 is determined based on chaos theory. In particular,
When the total number of the 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 equation (4) A chaos sequence, which is a pseudo-random number corresponding to each blade 12, is obtained based on the function, and the angle is determined using the chaos sequence according to the following equation (5). In this embodiment, the total number B of the blades 12 is 35.

[0034]

(Equation 7)

[0035]

(Equation 8) The cross flow fan 11 is formed by sequentially arranging the blades 12 having the determined angular interval (pitch) in the direction opposite to the rotation direction ω.

If the total of the angular intervals P (1) to P (35) of all the blades 12 does not always become 360 degrees, for example, the angular interval P (35) of the last blade 12 is set as follows. It may be adjusted so that the total sum becomes 360 degrees.

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

[0038]

[Table 1] Thereby, 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 performed using the crossflow fan 11 of the present invention having the above configuration will be described.

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

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

FIG. 6 shows the results of a noise experiment when the cross flow fan 11 set at the angular interval shown in FIG. 5 was rotated at 1360 rpm. Here, the horizontal axis in FIG. 6 indicates the frequency (Hz), and the vertical axis indicates the noise level (dB).

As can be seen from FIG. 6, the rotation primary sound NZ
(= 793 Hz) is 24 dB for the conventional configuration and 2 for the present configuration.
7 dB, which is slightly higher in the configuration of the present invention, but results in almost no difference. In FIG. 6, the result of the primary rotation sound when the angular interval between the blades 12 is equal pitch is indicated by a cross, and the value is 29 dB.

At 8N (= 181 Hz) on the low frequency side, the conventional product has 29 dB, whereas the present invention has a structure of 1 dB.
6 dB, which is a considerably low value, and shows that there is almost no fluctuation in the frequency region before and after the value.

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

The air that has passed through the lower part of the heat exchanger 2 is swirled at the base of the tongue 4a, and the swirl generated at the base is blown out of the cross flow fan 11 and
The noise increases when synchronized with the vortex generated by hitting a. However, by configuring the cross flow fan 11 at an angular interval according to the present invention, the noise component is dispersed in a wide band, and the noise level is reduced 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 represented by δP (n), if the manufacturing error satisfies −1.0 ≦ δP (n) ≦ 1.0. Showed no significant difference in the above-mentioned effects.

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

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

For example, in the description of the above embodiment, P (3
The angle interval of 5) is adjusted so that the total sum becomes 360 degrees. However, the present invention is not limited to this, and the angular interval of other blades 12 may be adjusted.

Alternatively, the above angle interval P (n) is determined by the following equation so that the sum of the angle intervals P (1) to P (35) of all the blades becomes 360 degrees. May be adjusted.

[0052]

(Equation 9) According to this configuration, all the blades 12 are arranged in a well-balanced manner at the angular intervals determined by the logistic mapping.

Further, the method of manufacturing the cross flow fan 11 is not limited to the method of combining one blade 12 with a plurality of support disks 13 as described above, but a plurality of blades around a single support disk. 12 may be configured to be sequentially stacked, or may be integrally formed (or divided into a plurality of parts) with a synthetic resin.

[0054]

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

[Brief description of the 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 one embodiment of the present invention.

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

FIG. 4 is an enlarged sectional view of the blade of FIG. 2;

FIG. 5 is a diagram showing an angle interval of a cross flow fan according to the conventional and the configuration of the present invention.

FIG. 6 shows a result of a noise test using the conventional product and the configuration of the present invention at the angular intervals shown in FIG.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body case 1a Suction port 1b Blow-out port 1c Rear guider 1d Rib 2 Heat exchanger 4 Stabilizer 4a Tongue surface 5 Ventilation path 6 Air filter 7 Front cover 7a Suction port 11 Cross-flow fan (cross flow fan) 12 Blade 13 Supporting disk 14 Rotation axis

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor friend Koizumi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Yoshinori Toya 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Kiyoshi Koyama 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Pref. Sanyo Electric Co., Ltd. (72) Shigeya Ishigaki 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Inside Sanyo Electric Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) F04D 17/04 F04D 29/28

Claims (8)

(57) [Claims] To claim 1. A periphery in the axial direction in a plurality of supporting discs arranged in a predetermined interval circumferentially in the lateral flow fan formed by arranging a plurality of vanes, said plurality of vanes in the circumferential direction, the following equation (1 )
A cross flow fan characterized by being arranged at intervals determined based on a logistic function . (Equation 1) 2. The plurality of blades have an angular interval P between an n-th blade and an (n + 1) -th blade centered on a rotation axis.
2. The cross-flow fan according to claim 1, wherein (n) is determined by the following equation (2) and arranged in the circumferential direction. (Equation 2) 3. An angular interval P (1) to P (B) of all blades.
3. The cross flow fan according to claim 2, wherein the angle interval P (n) of any one of the blades is adjusted so that the sum of the angles becomes 360 degrees. 4. The cross flow fan according to claim 3, wherein the angle interval P (B) of the B-th blade is adjusted. 5. An angular interval P (1) to P (B) of all blades.
3. The cross flow fan according to claim 2, wherein the angle interval P (n) is adjusted to P '(n) determined by the following equation (3) so that the sum of the angles becomes 360 degrees. (Equation 3) 6. A manufacturing error δP (n) of an angular interval P (n) of an n-th blade is formed so as to satisfy −1.0 ≦ δP (n) ≦ 1.0. The cross flow fan according to any one of claims 2 to 5, wherein 7. The method according to claim 7, wherein the plurality of blades includes the logistic.
2. The fan according to claim 1, wherein the fan is arranged in the direction opposite to the rotation direction of the cross flow fan at intervals determined based on the function.
7. The cross flow fan according to any one of claims 1 to 6. 8. A suction port, a heat exchanger, a cross flow fan, and an air outlet are sequentially arranged from the windward, and the cross flow fan circulates air in the conditioned room through the heat exchanger.
An air conditioner that heat-exchanges the heat medium flowing through the heat exchanger and the air to air-condition the interior of the conditioned room, wherein the cross flow fan is the cross flow fan according to any one of claims 1 to 7. An air conditioner characterized by the following.