JPS61277894A - Cross-flow blowing device - Google Patents

Abstract

PURPOSE:To muffle noise by having each of the tongue for plural stabilizers circumscribes the concentrical circles with their center located at the vane wheel shaft in such a way that the tongues are located in positions apart by a fixed angle and that a tongue faces another in each run. CONSTITUTION:At a position S1 passing through P1 apart by S from the circumference of a cross-flow fan vane wheel 1 and circumscribing a circle which has its center at the center O of the vane wheel shaft, a tongue part 2a of a stabilizer 2 is placed, while another tongue part 2b is put in a position S2 slided in the axial direction. Therefore, variations of sound pressure around the stabilizer is offset mutually, resulting in diminished vane pitch sound.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a cross-flow blower device widely used in air conditioners and the like.

BACKGROUND OF THE INVENTION Conventionally, this type of cross-flow blower has been developed, for example, by
As shown in Japanese Patent No. 41696, the configuration was as shown in FIGS. 8 and 9.

That is, a cross-flow fan impeller 1 is constructed by connecting a plurality of blades 5 and an end plate 5a supporting each blade 5 in the axial direction via a support plate 5b. A stabilizer 2 and a rear guider 3 were arranged in front and behind the center, and the stabilizer 2 and rear guider 3 formed an air outlet 4 to constitute a cross-flow blower.

As shown by the arrow in Figure 8, due to the structure of the cross-flow blower, the inflow and outflow directions of the air are opposite to each other, or when the blower is extended in the axial direction, it is proportional to the ratio of the length of the blower. The invention has become widely used in air conditioners, etc. in recent years because it has characteristics not seen in other blowers, such as increasing air volume. Stream blowers have problems such as high noise and low efficiency compared to other types of blowers, and in particular, the biggest challenge is to suppress the generation of unusual noise that occurs near the stabilizer 2. has been done. The frequency of this peculiar sound is the product of the number 2 of blades 5 of the cross flow fan impeller 1 and the number of revolutions per minute nrpm.
It appears as z and its overtones, and is usually called the vane pitch sound.

In this case, the frequency of the blade pitch sound is high, and the sound is audibly similar to a whistling sound and is perceived as very noisy.

In addition, the strength of the blade pitch sound changes depending on the shape and relative position of the rear fan impeller 1, stabilizer 2, and rear guider 3, or the load and other buttons, but the design that suppresses the blade pitch sound and the blower This is often at odds with designs that increase efficiency.

For example, in Figure 9, make the S dimension smaller. This improves blower efficiency, but increases blade pitch noise.

As described above, the cross-flow blower has a problem in that efficiency cannot be maximized in order to suppress the blade pinch noise.

In response to this, various attempts have been made in the past to weaken this blade pitch sound, and a typical example of such a countermeasure is the one shown in Japanese Utility Model Application No. 59-167990. be. Fig. 10 (a) h shows the relative position of the blades 5 of the conventional cross 70-fan impeller 1, the pitch angle ψ between each blade with respect to the center of the fan axis is equal, and the frequency characteristics are as shown in Fig. 11 ( As shown in a), the pitch angle ψ between the blades 5 is arranged randomly, and in the illustrated countermeasure example, the pitch angle ψ is 9° in the A part and 11° in the B part.
The blade pitch generated from this part is 36°.
0Xn 360Xn The frequency of sound is Hz and 1. x6゜Hz and 9×
60. Therefore, if the pitch angles are randomly arranged in the cross-flow fan impeller as shown in Fig. 11 (b
) K has the characteristics as shown, and is usually nXz
2XnXz s o HZ 1e. The peaks of the blade pitch sound appearing in HZ and its overtones interfere with each other and appear dispersed. As a result, the blade pitch sound is audibly mixed with sounds of other frequencies and becomes almost inaudible.

However, with this countermeasure, as shown in Figure 12, sound pressure fluctuations appear as a repetition of the same waveform for each rotation of the cross-flow fan impeller. Due to the frequency, an unpleasant rotating sound that is audibly rumbling, although not noticeable in terms of frequency characteristics, is newly generated and becomes a problem.

The present invention solves the above-mentioned conventional problems and provides a cross-flow blowing device with extremely low noise.

Means to Solve the Problems Therefore, the technical means of the present invention to solve the problem of the above-mentioned conventional example, which is the generation of blade pitch noise, and the generation of rotational noise newly generated due to the proposed countermeasure, is to Consisting of a plurality of stabilizers having the same cross-sectional shape or different cross-sectional shapes, the stabilizers are continuous in the axial direction of the impeller, and each of the tongues of the plurality of stabilizers is circumscribed by the same circle centered on the impeller axis, and a predetermined shape is formed. The configuration is such that the positions are shifted by an angle, and a pair of tongues are provided for each row of the impeller.
- are placed facing each other.

For production The effect of this technical means is as follows.

That is, the blade pitch noise generated near the stabilizer is thought to be caused by fluctuations in air pressure due to the proximity of each blade to the stabilizer. Therefore, the timing at which the blade pitch sound occurs can be dispersed by changing at least part of the position of the stabilizer to temporally shift the generation of the blade pitch sound occurring at ao HZ. I can do it. As a result, the blade pitch sounds with different timings interfere with each other, and audibly mix with other noises, making them almost inaudible.

Furthermore, as shown in FIGS. 14 and 15, the wind speed decreases significantly near the end plate 5a and support plate 5b of the cross-flow fan impeller 1, and the position of the tongue of the stabilizer and Since the wind speed similarly decreases near the area where the shape changes, the area where the wind speed decreases can be reduced by arranging each tongue part one-on-one for each row of the impeller as shown in Fig. 16. It can be minimized.

Furthermore, when the stabilizer of the present invention is used in a cross-flow fan in which the pitch angle between each blade is equal, the sound pressure fluctuation is caused by the relative position of the stabilizer with respect to the center of the impeller axis, as shown in Figure 4(b). There is a time difference by the amount of difference,
Since the sound pressure waveforms are the same, the repetition of the peculiar waveform caused by the rotational frequency of the four-ring fan shown in FIG. 12 does not occur, and the audibly unpleasant rumbling noise does not occur.

Furthermore, it has been analyzed from experimental results that similar effects can be obtained when the stabilizer of the present invention is used in the cross-flow fan shown in FIG. 10, but this will be discussed later.

Example Embodiments of the present invention will be described below with reference to the accompanying drawings.

Components that are the same as those in the conventional example are designated by the same reference numerals, and description thereof will be omitted.

1 and 2 illustrate the principle of the invention.

In the figure, the pitch angle between each blade is equal to the center of the impeller, passing through a point P1 that is distanced by a dimension S from the outer diameter of the cross-flow fan impeller 1, and centered around the axial center ○ of the cross-flow fan impeller 1. At the position S1 circumscribed to the circle,
One tongue portion 2a of the stabilizer 2 is disposed, and another tongue portion 2b of the stabilizer 2, shifted in the axial direction of the impeller 1, is disposed at a position S2 that circumscribes the same circle at a point P2. . Note that the other tongue portions 2c and 2d are also at the position S1,
They are arranged at positions S3 and S4 having the same relationship as S2. That is, the position S3 overlaps with Sl and S4/fiSq in the axial direction. Furthermore, each tongue part 2a s2b, 2c, 2d of the stabilizer 2 is attached to each impeller row.
are placed facing each other one on one.

In the following explanation, the relationship between positions S3 and S4 is
, and for convenience of explanation, only the positions S1 and S2 will be explained. The positions S1 and 82 are offset by an angle θ with respect to the axial center of the cross-flow fan impeller 1, and FIG. Indicated by (, ), (b).

Fig. 4 shows the relationship between time and sound pressure when using a conventional stabilizer with uniform side walls.
FIG. 4(b) shows a similar relationship when using a stabilizer according to the invention.

In this way, when the present invention is used, the two waveforms interfere with each other, producing a canceling effect. As a result, changes in sound pressure near the stabilizer are reduced by canceling each other out, and blade pitch noise is reduced.

Furthermore, since a cross 70-fan with an equal pitch is used, the waveform of the sound pressure fluctuation does not change, and as shown in Fig. 12, there is no repetition of the peculiar waveform caused by the rotational frequency of the fan, which improves the auditory sense. Explain that specific experiments have confirmed that this is caused by discomfort.

As an example using the present invention, the following experiment was conducted using the same equal pitch fan as shown in FIG. 4(b).

■ Changed S dimension ■ Changed rotation speed There are two types, and the frequency characteristics of these experiments are limited.

The blade pitch sound disappeared in , indicating that the effect of the present invention was not caused by the S dimension or rotation speed. Furthermore, since there is a correlation between the S dimension and the fan diameter, it can be said that this is not caused by the fan diameter. Therefore, it can be considered that the effect of reducing blade pitch noise and rotational noise when the stabilizer of the present invention is used for a constant pitch cross flow fan is due to the stabilizer of the present invention. Furthermore, as shown in FIG. 16, each row of impellers and each tongue portion of the stabilizer are disposed to face each other one-on-one, so that the area where the wind speed decreases can be minimized.

Furthermore, the results of frequency characteristics when the stabilizer of the present invention is used in a cross-flow fan with an unequal pitch are shown in Fig. 3 (,); As in the case, blade pitch noise and rotation noise are reduced. This is considered to be because, as shown in FIG. 13, the unique sound pressure waveforms shown in FIG. 12 interfere with each other as a temporal result while maintaining their specificity. Therefore, the stabilizer of the present invention
It can be said that it can be applied not only to uniform pitch cross flow fans but also to unequal pitch cross flow fans.

5 and 6 show a structural diagram and a sectional view of essential parts of an embodiment used as an actual air conditioner based on the principle of the present invention. In the figure, 6 indicates a 7 am motor. Further, FIG. 7 is a sectional view of a main part of another embodiment of the present invention. These are arranged at different positions S1 and 82 when the tongues of the stabilizer 2 approach each other. In other words, Figure 4 (a), (b)
), the peak positions of the sound pressure waveforms shift, and the waveforms interfere with each other, reducing noise.

Note that the stabilizer 2 can be easily manufactured by molding resin or the like. Also stabilizer 2
The shape of the tongue portion may be an acute angle, an acute-angled circular arc, or even a simple circular arc shape.

Effects of the Invention As described above, by using the stabilizer of the present invention, it is possible to provide a quiet blower with no audibly unpleasant blade pitch noise or rotating noise, and furthermore, it is possible to provide a quiet blower that does not produce audibly unpleasant blade pitch noise or rotating noise. Since the step part of each tongue part is located at the part), it is extremely unlikely to be affected by the thinness that occurs at this part.
It becomes possible to significantly improve blower efficiency, which until now has been limited by noise.

[Brief explanation of drawings]

Figures 1 and 2 are a perspective view and a sectional view of the main parts showing the principle of the blower device of the present invention, Figures 3 (&), (b),
(c), (d), (,) are frequency characteristic diagrams showing the noise and comparison between the conventional example and the embodiment of the present invention, respectively, and Fig. 4 (,), (b) are the frequency characteristics diagrams of the conventional example and the embodiment of the present invention, respectively. A sound pressure waveform diagram showing a comparison of sound pressure levels according to an example; FIGS. 5 and 6 are a plan view and a cross-sectional view of essential parts, respectively, showing an example in which a blower according to an embodiment of the present invention is applied to an air conditioner; FIG. 7 is a view corresponding to FIG. 6 showing another embodiment of the present invention, FIGS. 8 and 9 are a perspective view and a sectional view of essential parts showing the structure of a conventional blower device, respectively, and FIG. ) and (b) are sectional views of essential parts of impellers showing different conventional examples, respectively, and Fig. 11 (,), (b)
are frequency characteristic diagrams of a blower equipped with an impeller according to FIGS. 10 (, ) and (b), respectively. FIG. 12 is a sound pressure waveform diagram of a blower equipped with a conventional impeller, and FIG. 13 is a diagram of the present invention. FIG. 14 and FIG. 16 are wind speed distribution charts for the impeller side and stabilizer side, respectively, and FIG. 16 is a wind speed distribution chart for the embodiment of the present invention. 1... Impeller, 2... Stabilizer,
2a. 2b, 2c, 2d...tongue, 3...rear guider, 4...outlet, 5...blade, 5a...end Board, 5b...Support board, 6...7 Unmotor. Name of agent: Patent attorney Toshio Nakao and 1 other person!・
1. 0 space a - 1 space 7 possible, Koma-tase car. 21. Stabilizer” 2a, 26, 2c, 2d - Tongue Fig. 1
5., Arade'6a... Base plate 51L... Support bag f111 wings, 21.9 squares, 2 T. Figure 3 = I Rubber (Shiwarm - L - (Hxλ Figure 3 (C) Tadazaka San (Hz Figure 3 (e) i 5et (b) Figure 5 1., 0 Zuft fan impeller ?11. Suda do'rises' 311. Rear card 5, ,,, land handling 66,... verse plate 6... fan 7-ta fl,, cross 70- Juan J town oro j F. !6 figure
21.・Stabilizer size J... Rear is broken 4...Air outlet 5...Fray ridge f...-Cross flow-27, U missing, Outlet 5... ... Field 3... Soarby 9 4... Outlet 5... Field 1... Reverse U flow fan Hassha 4... Outlet 5... Field' Figure 1O (ωth]] Figure M filtration (Hz) (b) M liquid sensitivity (Hw) Figure 12-t Set: Figure 13 1 Sec Figure 14 Figure 15 Figure 16, ?

Claims (3)

[Claims] (1) A cross-flow type impeller is constructed by connecting a plurality of blades and a support plate that supports the blades in multiple axial directions, and furthermore, this impeller and a fan motor that drives this impeller are connected in multiple axial directions. , a rear guider, and a stabilizer constitute a cross-flow blower, the stabilizer is provided with a plurality of tongues, and the tip of each tongue is located on the same circumference centered on the impeller axis, and adjacent mutual tongues The cross-flow blower is configured such that the tongue portions are positioned with a predetermined angular shift, and each tongue portion is opposed one-to-one for each row of the impeller. (2) The cross-flow blower device according to claim 1, wherein each tongue has the same cross-sectional shape. (3) The cross-flow blower device according to claim 1 or 2, wherein the pitch angle between each blade in each series of impellers is arranged so as not to be constant.