JPS60166789A - Vane wheel for transverse-flow blower - Google Patents

Abstract

PURPOSE:To reduce noise and improve blowing efficiency by installing plural kinds of each series consisting of different number of pieces of blades arranged at equal pitch interval and arranging each contiguous series in different kind, in a transverse-flow blower. CONSTITUTION:Plural kinds of each series 7, 8 having a different number of pieces of blades 6 by varying the pitch angle of the blade 6 are installed, having the same specifications of the blade 6. Each contiguous series is different in kind and assembled so as to be continuous at the position in the direction of each revolution shaft. Therefore, the time when an nz-sound is generated becomes different for each series, and the generation of the nz-sound can be markedly reduced easily and the efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is widely used as a blower for an air conditioner, etc.
The present invention relates to an impeller designed to reduce noise in cross-flow blowers.

Conventional Structure and Problems Generally, as shown in FIG. 1, a cross-flow blower has a structure in which an impeller 1 is centered, and a stabilizer 2 and a rear guider are disposed in front and behind the impeller 1. As for the impeller 1, disc-shaped end plates 4 are arranged at both ends, and several disc-shaped or doughnut-shaped partition plates 5 are arranged at intervals between the two end plates. It has a structure in which they are connected by blades 6. Note that one section divided by the end plate 4 or the partition plate 5 is called a normal speed.

As shown by the arrows in Figure 1, a cross-flow blower has a structure in which the inflow and outflow directions of electricity are opposite, or the further the blower is extended in the axial direction, the more the airflow increases in proportion to its length. Because it has features not found in other blowers, such as increased
In recent years, it has become widely used in electrical conditioners. However, on the other hand, cross-flow blowers also have problems that need to be solved in the future, such as high noise and low efficiency.

In particular, regarding noise, the frequency generated from the interference between the stabilizer 2 and the blades 6 of the impeller 1 is expressed as the product nz of the rotation speed n and the number of blades 2. There is a tendency for singular sounds, generally called nz sounds, to occur at high levels.

The nz sound is a peculiar sound that is widely seen in other types of blowers, but in general, in cross-flow blowers with a large number of blades,
In particular, because the frequency of the nz sound becomes high, it is perceived as a very noisy sound to the human ear, similar to whistling. The height of the nz sound changes depending on the shapes, relative positions, loads, etc. of the impeller 1, stabilizer 2, and rear guider 3, but a design that suppresses the nz sound and a design that increases blower efficiency are often contradictory.

For example, it is already widely known that the minimum distance 74 dimension between the stabilizer 2 and the impeller 1 is a factor that has a very large influence on the performance of a cross-flow blower, but reducing the 77 dimension will increase the efficiency. On the other hand, the nz sound becomes louder.

As in this example, there is a limit in the cross-flow blower in that efficiency cannot be raised to the maximum in order to keep the nz sound low.

Conventionally, various attempts have been made to reduce this nz sound, and one typical example will be explained with reference to FIG. 2.

In FIG. 2a showing the non-countermeasure structure, six blades 6 are installed in the same direction and at the same position, so this impeller 1
A schematic representation of the nz sound emitted from the waveform shown in FIG. 3a is shown in FIG.

In contrast, in FIG. 2, which shows a countermeasure structure, one set of blades 6 is shifted by 1/2 pitch from the adjacent blades 6 on both sides. Here, the pitch refers to the angle between the blades 6 in the circumferential direction, and the angle θ in tJ FIG. 4.

``As a result, the nz sound becomes as shown in FIG. 3(b), where waves of the same waveform with a phase shift of 180 degrees interfere with each other, resulting in a smoother waveform than in the structure without countermeasures. This smooth waveform made the nz sound difficult for human ears to hear.

However, in recent years, as blowers have become more efficient, there has been a demand for blower designs that tend to produce higher nz noise.
The waveform shown in the figure changed to the waveform shown in FIG. 3C. As a result, not only the original nz sound cannot be suppressed sufficiently, but also the new 2
This resulted in the appearance of nZ sound, making the blower extremely audible.

Purpose of the Invention In view of the above, the purpose of the present invention is to reduce noise (n
The purpose of this project is to reduce the noise (Z noise) and increase the efficiency of the cross-flow blower.

Structure of the Invention In order to achieve this object, the present invention provides a plurality of series in which the number of blades in the series is different from each other, each consisting of a group of blades formed by arranging blades of the same type in a cylindrical shape at equal pitch intervals. The six matching stations are assembled by disposing different types of stations at positions in the direction of the rotational axis.

With this configuration, the waves of the same waveform generated from the 6th gear interfere with each other to form a smooth waveform, thereby reducing noise (NZ sound) and increasing the efficiency of the cross-flow blower.

DESCRIPTION OF EMBODIMENTS The present invention will be explained below with reference to FIGS. 5 to 7 showing one embodiment thereof. Here, in order to clarify the difference from the conventional technology, the explanation will be partially using FIG. 4, and the conventional example and 1 (
"" Some parts are given the same drawing numbers and detailed explanations are omitted.

In FIG. 4, conventionally, the impeller 1 is constructed by keeping the specifications of the blades 6, the pitch angle θ of the blades 6, the number of blades 6, etc. constant, and six sets are arranged as shown in FIG. 2a.

As shown in b, they are assembled in series in the direction of their respective rotational axes. Here, if the number of blades is 2, then in this impeller the blade pitch angle θ is uniformly 3e.
o/z (d e g ). However, the cross section of six series of impellers according to the present invention is shown in FIG. 6a.

Referring to a partially enlarged continuous sectional view of the cross-flow blower impeller shown in b, there are multiple types in which the specifications of the blades 6 are the same, but the pitch angle θ of the blades 6 is changed, and the number of blades 60 is different. As shown in FIG. 6, six sets of six sets 7°8 are assembled, with six sets of adjacent sets having different types and arranged in series at positions in the direction of the rotational axis.

Now, looking at FIG.
Since there are 360 x n/10 degrees, the frequency of nzi'S generated from this series is 360×n/10°. Also, looking at Figure 5, the blade pinch angle θ is 9 degrees, and therefore the number n of six blades is 40, so the n generated from this series is
The z sound is 360 x n/9°. Therefore, the impeller according to the present invention generates nz sounds of different frequencies as many as the number of series having different types of blade pitch angles θ.

By the way, when such multiple types of strings are combined by consecutively arranging different types of strings in the direction of each other's rotational axis for adjacent strings, the timing at which the nz sound occurs will be different for each string. As a result, a combination of sounds with several different frequencies is generated. FIG. 7a shows the frequency characteristics representing the NZ sound and 2nZ sound generated by the conventional product, and it can be seen that very high peaks appear at one location.

On the other hand, in the frequency characteristic representing the nz sound generated from the impeller according to the present invention shown in FIG. 7, many low peaks can be seen. When the human ear hears this, the former sounds like a high-pitched whistling sound, while the latter is mixed with other noises and is almost inaudible.

In the above example, chains having two types of pinch angles θ are combined, but the effects of the present invention can be further increased by increasing the number of chains having different pitch angles θ.

Although the number of blades 6 is a factor that greatly affects air volume, wind pressure, noise, etc., the range of change in the number of blades 6 necessary to achieve the purpose of the present invention is small and does not affect the above performance. has almost no effect.

Effects of the Invention As described above, the present invention provides a plurality of types of impeller trains for a cross-flow blower, each of which has a different number of blades, each of which is made up of a group of blades made up of blades of the same type arranged in a cylindrical shape at equal pitch intervals. The six adjacent sets provided are impellers of a cross-flow blower assembled by disposing sets of different types at positions in the direction of each other's rotation axis. Therefore, the nz sound, which has conventionally been considered a serious drawback of cross-flow blowers, can be reduced very easily and greatly, and moreover, there is no increase in other noises or decrease in efficiency due to this. Furthermore, compared to conventional
In order to prevent the Z noise, the design of the position and shape of the stabilizer and rear guider, which was previously limited to a wide range, can now be designed more freely, which greatly contributes to improving the efficiency and performance of the blower. .

[Brief explanation of drawings]

Figure 1 is a perspective view schematically showing a cross-flow blower, Figure 2a,
bi A partial front view showing different conventional impellers,
FIGS. 3a, b, and c are schematic diagrams showing nz sound waveforms generated from different conventional impellers, FIG. 4 is a sectional view of the conventional impeller, and FIG. 5a. b is an enlarged sectional view of different parts of an impeller showing one embodiment of the present invention, FIG. 6 is a front view of the impeller of the present invention, and FIG. Noise Jg
-1 wave number characteristic diagram. 1... Impeller, 2... Stabilizer, 3...
...Rear guider, 4...End plate, 5...Partition plate, 6...Blade. Name of agent: Patent attorney Toshio Nakao and 1 other person @1
Figure 1m311 (cb) (12) Uruma - Poetry Closure - (C1 minute M-

Claims (1)

[Claims] Multiple types of the above descriptions are provided in which the numbers of blades in the series are different, each consisting of a group of blades made up of blades of the same type arranged in a cylindrical shape at equal pitch intervals. A cross-flow blower impeller assembled in an axial position.