JP3484854B2 - Once-through fan - 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, and is intended to suppress the generation of noise particularly in a low frequency band due to the rotating sound of an impeller.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional air conditioner indoor unit 5 is provided with an air blowing nozzle 7 in a lower portion of a front surface of a casing 6, an air suction port 8 above the air blowing nozzle 7, and a rear side thereof. The heat exchanger 9 is arranged so that the air introduced from the air suction port 8 is transferred to the heat exchanger 9 by the cross flow fan impeller 4 arranged between the casing 6 and the heat exchanger 9. When passing, heat is exchanged to make cold air or warm air, and the air is blown out from the air blowing nozzle 7.

As shown in FIG. 8, the cross flow fan impeller is provided with a plurality of partition plates 3 perpendicular to the rotation axis, and a plurality of blades 1 between the partition plates with a periodical blade mounting interval. It is a thing. Here, in order to reduce a sound generated when the impeller 4 rotates, that is, a fan rotating sound (hereinafter, referred to as NZ sound) related to the number of blades, for example, Japanese Patent Laid-Open No. 60-17296. As shown in the figure, the blades 1 are arranged by randomly mounting the mounting intervals without periodicity.

[0004]

The conventional through-flow blower impeller is constructed as described above, and the result of the noise value frequency analysis of the impeller of the construction shown in FIG. 10 shows a result of noise value frequency analysis of an impeller having a configuration in which the blade mounting intervals have no periodicity as shown in Japanese Patent Laid-Open No. 60-17296. When the blade is attached as in Japanese Patent Laid-Open No. 60-17296, it is possible to reduce the NZ noise, but as shown in FIG. 10, low frequency noise of 600 Hz or less is newly generated. .

FIG. 10 shows a simulation result of frequency analysis when the blades are arranged in a random number by the following equation (2).

[0006]

[Equation 2]

This is because when the blades 1 of the once-through fan impeller 4 pass near the stabilizer 10, the noise generated from the pressure fluctuations generated in the blades 1 is increased between the blades 1 as the distortion coefficient δ increases. The correlation becomes smaller and the NZ sound is reduced, while the fan rotation sound (hereinafter referred to as N sound) generated independently is conspicuously generated in the low frequency band.

Therefore, the present invention reduces the NZ sound,
Further, it is an object of the present invention to obtain a cross flow fan impeller in which noise generation of N sound in a low frequency band (600 Hz or less) is also suppressed.

[0009]

According to a first aspect of the present invention, there is provided a cross flow fan impeller in which an installation angle θk for determining a mounting position of the blade is determined according to the following equation with a reference blade as a mounting position of the blade. When the blade number arranged when the blade arranged at the reference angle is 0 is k, the blade angle is defined by the arrangement angle variation amount α and the cyclic order β as shown in the following Expression 3.

[0010]

[Equation 3]

According to the second aspect of the present invention, the once-through blower impeller has a cyclic order β of a natural number of 2 or more.

According to the third aspect of the present invention, the through-flow fan impeller has a cyclic order β that is a natural number of 2 or more and that is an even number.

In the once-through blower impeller according to the fourth aspect of the present invention, the arrangement angle variation amount α is a rational number in the range of 0 <α <1.

The cross flow fan impeller according to claim 5 of the present invention is formed with a skew angle.

According to a sixth aspect of the present invention, there is provided a cross flow fan impeller having a skew angle and a cyclic order β of 2
The above is a natural number.

According to a seventh aspect of the present invention, there is provided a cross flow fan impeller having a skew angle and a cyclic order β of 2
The above is a natural number and an even number.

According to the eighth aspect of the present invention, there is provided a cross flow fan impeller having a skew angle, and the arrangement angle variation amount α is 0 <
It is a rational number in the range of α <1.

[0018]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. FIG. 1 shows a first embodiment of the present invention.
In FIG. 1, 1 is a blade, 2 is a reference blade, 3 is a partition plate,
θ is an arrangement angle that determines the blade attachment position, and 4 is an impeller formed by the arrangement angle θ that determines the blade attachment position on the blade 1, the reference blade 2, and the partition plate 3. The blade mounting shows the formula of the position angle in Equation 4,

[0019]

[Equation 4]

And the arrangement angle variation amount α = 0.
2, cyclic order β = 2, blade angle d at equal intervals
This is an arrangement angle that determines the blade mounting position when θ = 2π / 35 and the arrangement angle θk0 = 2π × k / 35 when the blades are arranged at equal intervals.

FIG. 2 shows an air conditioner incorporating the impeller 4 of Embodiment 1 of the present invention. Reference numeral 5 is an indoor unit of an air conditioner, 6 is a casing, 7 is an air outlet, 8 is an air inlet, 9 is a heat exchanger, and 10 is a stabilizer. FIG. 3 shows a diagram in which the position of the blade 1 according to the first embodiment of the present invention is compared with a sine curve.

In the once-through blower impeller according to the first embodiment of the present invention, since the mounting position of the blade 1 is cyclically changed, the NZ sound is modulated and the peak level is dispersed as shown in FIG. While the noise level decreases, the noise level is suppressed because the N sound generated independently remains in correlation.

Embodiment 2. The cross flow fan impeller according to the second embodiment of the present invention has a cyclic order β that is a natural number of 2 or more in the first embodiment, and as a result, the modulation is large and the cyclic effect is sufficiently effective. Can be obtained.

Embodiment 3. According to the once-through blower impeller of the third embodiment of the present invention, when the cyclic order β is a natural number of 2 or more and is an even number in the first embodiment,
Mechanical balance can be achieved at the same time.

Fourth Embodiment The once-through air blower according to the fourth embodiment of the present invention is the ratio of the arrangement angle variation α in the range of 0 <α <1 in the first embodiment. As a result, the wings are not evenly spaced and do not overlap with the adjacent wings.

Embodiment 5. It is generally known that, in the once-through blower impeller of Embodiment 5 of the present invention, the one having a skew angle θ ′ as shown in FIG. 6 has a great effect on reducing the NZ sound. The first embodiment is added to this. Thereby, a synergistic effect can be obtained in reducing the NZ sound.

Sixth Embodiment In the once-through blower impeller according to the sixth embodiment of the present invention, the cyclic order β is a natural number of 2 or more in the fifth embodiment. As a result, a large amount of modulation is required, and a sufficient cyclic effect can be obtained.

Embodiment 7. The once-through blower impeller according to the seventh embodiment of the present invention can have mechanical balance at the same time as in the fifth embodiment, if the cyclic order β is a natural number of 2 or more and an even number.

Embodiment 8. In the once-through blower impeller of Embodiment 8 of the present invention, the arrangement angle variation amount α is a rational number in the range of 0 <α <1 in Embodiment 5 described above. As a result, the wings are not evenly spaced and do not overlap with the adjacent wings.

[0030]

The cross flow fan impeller according to claim 1 of the present invention is provided with a plurality of partition plates perpendicular to the rotation axis and a plurality of blades between the partition plates, and the mounting positions of the blades are as follows. Since it is arranged at intervals according to the formula shown in 1,

[0031]

[Equation 5]

Since the mounting positions of the blades are cyclically changed, the NZ sound is modulated, the peak level is dispersed and the noise level is lowered, while the N sound generated independently remains the noise. The level has the effect of being suppressed.

Since the once-through type blower impeller according to claim 2 of the present invention has a structure in which the cyclic order β is a natural number of 2 or more, there is an effect that a sufficient cyclic effect can be obtained.

Since the cross flow fan impeller according to claim 3 of the present invention has a structure in which the cyclic order β is a natural number of 2 or more and an even number, the mechanical balance of the cross flow fan can be achieved. Have an effect.

In the once-through blower impeller according to claim 4 of the present invention, when α = 0, the blades are attached at equal intervals, and it becomes impossible to reduce the NZ noise, and α =
When it is 1, the blade overlaps with the adjacent blade, but since the arrangement angle variation amount α is set to 0 <α <1, it has an effect that the blade intervals are not even and do not overlap with the adjacent blade.

The cross flow fan impeller according to claim 5 of the present invention has a structure in which the structure of claim 1 is added to the cross flow fan impeller having a skew angle. Therefore, as shown in FIG. As shown in FIG. 8, the peak sound that cannot be suppressed is further suppressed.

According to a sixth aspect of the present invention, there is provided a cross flow fan impeller having a skew angle and a cyclic order β of 2
Since the above natural number configuration is adopted, it is possible to obtain a sufficient cyclic effect.

Since the cross flow fan impeller according to claim 7 of the present invention has a structure in which the skew angle is provided and the cyclic order β is a natural number of 2 or more and an even number, the mechanical balance of the cross flow fan impeller is Has the effect of being able to take.

According to the eighth aspect of the present invention, the cross flow fan impeller has a skew angle, and the arrangement angle variation amount α is 0 <
Since the ratio is a rational number in the range of α <1, it has an effect that the blade intervals are uniform and do not overlap with the adjacent blades.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cross-flow fan impeller showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an air conditioner incorporating the once-through blower impeller according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram comparing the blade position of the first embodiment of the present invention with a sine curve.

FIG. 4 is a characteristic diagram showing a noise value frequency analysis result of the once-through blower impeller according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a skew angle of a once-through blower impeller according to a fifth embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a result of noise value frequency analysis of a once-through blower impeller with only a skew angle according to the fifth embodiment of the present invention.

FIG. 7 is a conventional air conditioner indoor unit.

FIG. 8 is a conventional once-through blower impeller.

FIG. 9 is a characteristic diagram showing a noise value frequency analysis result of a conventional once-through air blower having a periodic blade attachment interval.

FIG. 10 is a characteristic diagram showing a result of noise value frequency analysis of a conventional cross-flow fan.

[Explanation of symbols]

1 blade, 2 reference blade, 3 arrangement angle that determines the blade mounting position, 4 partition plate, 5 skew angle, 6 casing, 7 air blowing nozzle, 8 air suction port,
9 heat exchanger, 10 stabilizer, 11 through-flow fan

Claims (8)

(57) [Claims] 1. A plurality of partition plates perpendicular to a rotation axis, and a plurality of blades between the partition plates, wherein the blades are mounted at intervals according to the formula shown in the following formula 1. Once-through blower impeller. [Equation 1] 2. The cross flow fan impeller according to claim 1, wherein the cyclic order β is a natural number of 2 or more. 3. The cross flow fan impeller according to claim 1, wherein the cyclic order β is a natural number of 2 or more and is even. 4. The cross flow fan impeller according to claim 1, wherein the arrangement angle variation amount α is a rational number in a range of 0 <α <1. 5. The cross flow fan impeller according to claim 1, which is formed with a skew angle. 6. The cross flow fan impeller according to claim 5, wherein the cyclic order β is a natural number of 2 or more. 7. The once-through blower impeller according to claim 5, wherein the cyclic order β is a natural number of 2 or more and an even number. 8. The cross flow fan impeller according to claim 5, wherein the arrangement angle variation amount α is a rational number in the range of 0 <α <1.