JPH06173886A - Cross flow fan - Google Patents

Abstract

PURPOSE:To restrain the occurrence of NZ (pecurier) sounds as low as possible in driving cross flow fans. CONSTITUTION:When blades 14 between a series of fan bodies 15 make an angle by each other, respective blades 14 of the fan body 15 adjacent to the respective blade 14 of one fan body 15 are mounted in positions deviated by a phase of about 3/10 of the angle between the blades and the mounting phase angles of blades 14 in the respective fan bodies 15 are constituted to be positioned in positions as different as possible.

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 widely used as a blower or the like equipped in various air conditioners.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, a cross-flow fan of this type has disk-shaped end plates 2 and 2 arranged at both ends in the axial direction of a rotary shaft 1, and the end plates. No. 2 having substantially the same diameter as that of No. 2 or a plurality of partition plates 3 made of a disk provided with a rotary shaft insertion hole at the center. The partition plates 3 are arranged such that the side surfaces of the adjacent partition plates 3 and 3 and the side surfaces of the end plates 2 and the partition plate 3 adjacent to the end plates 2 face each other at a predetermined interval.

Further, the end plate 2 and the partition plate 3 facing each other,
And a unit number of blades 4, 4, ... Are integrally mounted in the circumferential direction between the respective partition plates 3, 3, whereby the end plate 2 and the partition plate 3 facing the end plate 2 or adjacent partition plates A fan assembly 5 is constituted by 3, 3 and the unit number of blades 4, 4, ....

By the way, the unit structure 5 of the fan, that is, one section divided by the end plate 2 or the partition plates 3, 3, ... Is usually called a ream, and the ream 5, 5, ... A horizontally long cross flow fan Ac is formed by being continuously arranged in the axial direction of the shaft 1.

Generally, this cross flow fan Ac
The stabilizer Bc is disposed in the lower front part of the rear guide C at the center and the rear guide C
By disposing c, a cross flow fan can be constructed.

In this cross-flow fan, as shown by the white arrow in FIG. 6, the air flow introduced from the axial direction of the cross-flow fan Ac which is rotationally driven is forwardly flown by the blades 4, 4, ... Of the cross-flow fan Ac. It converts into a unidirectional flow having a two-dimensional spread, and is widely used in air conditioners and the like as described above.

The above-mentioned cross-flow blower is required to have both a small size and a large air volume in response to the recent demand for thin and compact air conditioners and improved air conditioning performance. Increasing the noise generated by a cross flow fan is an important issue.

As the noise generated when the cross flow fan is driven, an offensive peculiar sound caused by the interference between the rotating blades 4, 4 of the cross flow fan Ac and the stabilizer Bc is a particular problem.

This peculiar sound is commonly called NZ sound.
The blades 4, 4, ... And the stabilizer Bc of the cross-flow fan Ac are designed to increase the size and volume of the blower.
If the gap between them is set small, it tends to occur frequently. The frequency of the NZ sound is represented as a product N · Z of the rotation speed N of the fan Ac and the number of blades Z, and is often particularly remarkable in a crossflow fan having a large number of blades 4, 4, ... .

The magnitude of the NZ sound varies depending on the shapes and relative positions of the cross flow fan Ac, the stabilizer Bc, and the rear guider Cc, the load, and the like.
Aiming to reduce Z sound is often a conflicting task.

For example, in order to realize the downsizing of the blower and the increase of the air volume, the blades 4, 4 of the fan Ac and the stabilizer Bc are arranged in close proximity to each other, and the heat exchanger of the air conditioner and the blower are crossed. If the distance from the flow fan is shortened, the blades 4, 4, ... Of the cross flow fan Ac will interfere not only with the above-mentioned stabilizer Bc but also with the heat exchanger. Also occurs between the heat exchanger and the heat exchanger, resulting in an inconvenience that noise is further increased.

By the way, the generation of the NZ sound as described above is
It is known that this is greatly related to the arrangement of the blades 4, 4, ... In the cross flow fan Ac. For example, as shown in FIG. 7, in the case where the blades are not provided with measures, the blades 4, 4, ... Are arranged at equal positions in the circumferential direction in one fan assembly 5, and the fan assembly 5 of each series is arranged.
Although the phases of blade arrangement are set to be the same over 5 ..., It is impossible to reduce the NZ sound with such a configuration.

On the other hand, in the cross-flow fan Ad shown in FIG. 8, for example, the blades 4, 4, ... Are arranged at equal circumferential positions in one continuous fan assembly 5 in that the fan Ac shown in FIG. However, the blades 4, 4, ... Are arranged between the adjacent fan structures 5, 5 with a phase shift of 1/2 of the blade angle in the circumferential direction.

The cross flow fan Ad having such a NZ noise reduction measure, when compared with the cross flow fan Ac having no measure shown in FIG. 7, has the blades 4 in each of the fan structures 5, 5 ,. It has been found that the NZ noise is slightly reduced under certain design conditions of the blower due to the effect that the mounting phases of 4, ... Deviate by 1/2 of the angle between the blades.

Further, as an NZ sound reduction measure different from the above-mentioned conventional example, as in the prior art example disclosed in Japanese Patent Laid-Open No. 60-17296, the mutual pitch of the blades in one of the cross-flow fans is increased. There is a random array of angles.

[0016]

However, as the fan design is required under the condition that the NZ noise becomes high as the fan efficiency is pursued, it is possible to improve the efficiency of the fan as shown in FIG. If the installation phases of the blades 4, 4, ... Of the matching fan structures 5, 5 are shifted by 1/2 of the angle between the blades, not only the original NZ sound is not sufficiently reduced, but also the blades 4, 4 ,. When the unit number is an odd number, the phases are shifted by 180 °, so that the sound of twice the frequency of the NZ sound is overlapped and the 2NZ sound becomes very loud, which is not preferable in terms of hearing.

Further, as an extension of the conventional example, the phase of each series of blades 4, 4, ...
It is possible to shift by 3 or 1/4,
Those shifted by ⅓ generate 3NZ sounds, and those displaced by ¼ generate 2NZ sounds and 4NZ sounds. Further, as a matter of course, when the phase shift of the adjacent blades is reduced, the NZ sound reduction effect obtained by shifting the blade arrangement phase is reduced.

Further, in the case of the prior art example, since the arrangement of the blades in the circumferential direction is based on a random number array, when attention is paid to one blade in one series, the blades in the adjacent series are It is possible that they are arranged at the same phase angle, and in such a case, sound is generated at the same phase position of each series. Therefore, even if the angle between the blades in one fan structure is varied, when there are blades arranged at the same phase angle in the axial direction of the rotating shaft between the fan structures of each series,
The NZ sound does not fall sufficiently.

When adjacent blades are arranged at different phase angles, the NZ sound is reduced, but in any case, in the random number array, the blade mutual pitch of one of the blades is changed, and in terms of blowing performance, Because it is out of the proper pitch,
It is inevitable that the blower efficiency will drop. Further, as the number of stations increases, the probability that the blade arrangement phase angle becomes the same in two or more stations increases, so that it is difficult to apply the blade to a multi-type cross flow fan.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and by arranging the blades of each series at positions which are not the same in the circumferential direction as much as possible, N
It is an object of the present invention to provide a cross-flow fan which suppresses the generation of Z sound as much as possible and is excellent in quietness.

[0021]

SUMMARY OF THE INVENTION According to the present invention, a plurality of partitions made of discs having substantially the same diameter as the end plates are provided between the disc-shaped end plates disposed at both ends in the axial direction of the rotary shaft. A plate is arranged in parallel with the end plate at a predetermined interval, and the outer end edge of the blade has a unit number of blades between the end plate and partition plates facing each other and between adjacent partition plates. By mounting the end plate or the partition plate in a state of facing the outer peripheral edge of the end plate, a partition plate facing the end plate or adjacent partition plate, and a plurality of fan structure composed of a plurality of blades,
It is intended for a cross flow fan having a configuration in which it is continuously provided in the axial direction.

In order to achieve the above object, in the first configuration of the present invention, the angle formed between the straight lines connecting the blade centers adjacent to each other in the circumferential direction and the rotation axis in each fan assembly is defined as the inter-blade angle. Then, each blade of the adjacent fan structure is attached to each blade of one fan structure in a position shifted in phase by about 3/10 of the angle between the blades in the clockwise direction or the counterclockwise direction. I am configuring.

Further, in the second structure of the present invention, when the inter-blade angle θ = 360 ° / z (where z: the number of blades in each series), it is adjacent to each blade in one fan assembly. Each blade of the fan structure is (3/10) θ + α (where α ≦ in the clockwise or counterclockwise direction).
It is configured so that it can be mounted at a position shifted in phase by (1 / 2n). (360 ° / z), n: number of stations.

Further, in the third structure of the present invention, a plurality of blades arranged in a row in the axial direction of the rotating shaft in a row in the axial direction of the rotating shaft are respectively referred to as blade rows in a state where the mounting angle phases are close to each other in the fan structure of each series. At this time, all of the plurality of blades forming each blade row are arranged with different attachment angle phases.

Normally, blade mounting grooves are formed on the side surface of the end plate facing the partition plate and both side surfaces of each partition plate, and the blades are welded to these blade mounting grooves, respectively. To do.

[0026]

According to the above structure, the blade mounting phase angles between the fan assemblies in each series can be prevented from being at the same position as much as possible. Therefore, N generated in each station
Since the Z sound is out of phase with a random number, it is possible to reduce the NZ sound. Further, although the NZ noise can be reduced, the blades can be set to the optimum angle by disposing a plurality of blades in one group at equal positions in the circumferential direction. It can be manufactured at low cost without deteriorating at all.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. In the first embodiment shown in FIGS. 1 to 3, the present invention is applied to a cross flow fan installed in a cross flow fan. The cross flow blower shown in FIG. 1 includes a cross flow fan Aa and a stabilizer Ba arranged in the lower front part thereof.
And a rear guider Ca arranged at a position below the fan Aa from below.

The cross flow fan Aa has a rotary shaft 1
Disk-shaped end plates 12, 1 arranged at both ends in the axial direction of 1
2 and a plurality of partition plates 13, 13 ... Which are made of non-perforated discs or donut-shaped discs having substantially the same diameter as the end plate 12. The partition plates 13 are arranged such that the side surfaces of the adjacent partition plates 13 and 13 and the side surfaces of the end plates 12 and the partition plate 13 adjacent to the end plates 12 face each other with a predetermined interval.

Further, the end plate 12 and the partition plate 1 facing each other.
3, and the same number of blades 14, 14 ... At the circumferentially equally-divided positions between the partition plates 13, 13, their outer edge faces the outer edge of the end plates 12, 12 or the partition plates 13, 13. In this state, the end plates 12 and the partition plates 13 or the adjacent partition plates 13 and 13 are integrally mounted in this state.
And a unit number of blades 14, 14, ... Form one fan assembly 15, and each fan assembly 15
Are continuously provided in the axial direction of the rotary shaft 11 to form a cross flow fan Aa that is horizontally long as a whole.

FIG. 2 shows the blades 14 and 1 in each of the series.
4 is shown, and FIG. 3 partially shows a cross section of one continuous fan assembly 15 as viewed in the axial direction. As shown in FIG. 3, a side surface of each end plate 12 facing the adjacent partition plate 13,
, And blade mounting grooves 14a, 14a ... Are formed on both side surfaces of each partition plate 13, 13 ,.
4 and 14 are blade mounting grooves 14a and 14a, respectively.
It is welded to.

In FIG. 2, the numbers shown corresponding to the respective fan structures 15, 15 ... Of the fan Aa are the blades 14, 1 of the fan structure 15 located at the left end in the figure.
4 shows the blade arrangement phase angle of the leftmost station and the relative shift amount of each station with respect to the positions of 4 ...

Further, the numbers in the upper row are the angles with the blades 14 adjoining in the positive direction (counterclockwise direction), the lower numbers are the angles with the blades 14 adjoining in the negative direction (clockwise direction), θ
Indicates the inter-blade angle formed between the straight lines connecting the center of each blade and the rotation axis that are adjacent to each other in the circumferential direction in each series.

As shown in FIG. 2, in this embodiment, the blades 14, 14, ... Adjacent to one blade 14, 14, ... It is supposed to be attached at an angular position where the phase is shifted by 3/10, in other words, by 7/10 in the opposite direction.

Further, in this embodiment, the fan structures 15, 15 are
The case where the number of stations of ... Is 10 is shown. If the number of stations is 10 or less, the blade positions of each station will not come to the same position in the circumferential direction. In the case of 11 or more stations, there will be two or more fan structures 15 at the same blade position, but 1 in the meantime.
Since there is a distance of 0 or more, there is almost no effect.

In this way, the adjacent blades 14, 14
Is displaced with a significant phase difference of (3/10) θ or (7/10) θ, so the phase of the NZ sound should be effectively shifted, unlike the case where the blades of the adjacent series are small in displacement. You can As a result, with a simple and simple structure, it is possible to significantly reduce the NZ sound and the peak sounds (2NZ sound, 3NZ sound ...) Of a frequency that is an integral multiple of the NZ sound, as compared with the conventional case. Further, at the time of manufacturing, since the angle θ between the blades in the series can be set to an optimum angle with high air blowing efficiency, no other increase in noise or reduction in air blowing efficiency appears.

FIG. 4 is a cross flow fan Aa of this embodiment.
And the cross-flow fan Ad of the comparative example are used for the blower provided with the same conditions, and the result of the noise waveform measured is shown. As a comparative example, a fan in which adjacent series of blades as shown in FIG. 8 are arranged with their phases shifted by ½ of the angle between the blades in the circumferential direction was selected. In FIG. 4, (a) shows the measurement result of the present example, and (b) shows the measurement result of the comparative example.

In the comparative example, the second-order NZ sound appears particularly sharply, and the first-order NZ sound also appears at a high level. Therefore, the fan Ad of the comparative example hears a high-pitched sound such as a whistle blown by the NZ sound. On the other hand, in the fan Aa of the present embodiment, the phases of the blades 14, 14, ... Becomes

FIG. 5 shows a second embodiment of the present invention.
In FIG. 5, the numbers shown corresponding to the respective series of the fan Ab are the same as those in FIG. In this embodiment, when the blade angle θ = 360 ° / z (where z is the number of blades in each station), each blade 14, 14 in one station 15 is used.
For each blade 14, 14, ...
(3/10) θ + α (where α ≦ (1 / 2n) ・ (360
(° / z), n: number of stations), and the phase is shifted.

Now, the cross flow fan A shown in FIG.
If the number of blades in each station in b is 36 and the number of stations is 10, the inter-blade angle θ is θ = 360/36 = 1.
It becomes 0 °. Further, since α ≦ (1/2 · 10) · (360 ° / 36) = 0.5 °, if α is set to the maximum value of 0.5 °, the blades 14 of the adjacent stations 15 and 15, 1
4 ... is to be shifted by (3/10) θ + α = 3.5 °.

In this case, as is apparent from FIG. 5, the blades 14, 14 ... Are not at the same angle in the circumferential direction in any of the fan structures 15, 15, ... It can be seen that there is no fan structure 15 at a position shifted by 1/2.

In the case of the first embodiment, as shown in FIG. 3, for example, for the leftmost blades 4, 4, ... (0 °), the blades 4, 4, .. Position shifted by 1/2 of the inter-angle θ (5θ / 10)
Thus, the position is shifted by (1/2) θ for every 5 stations. However, since there are five continuous gaps between the two with a phase shift of (1/2) θ, they hardly affect each other, but both blades 4 and 4 have a secondary NZ sound with the same phase. Become.

The structure of the second embodiment has a structure in which the secondary NZ sound is reduced to a rate at which the second NZ sound is generated, and has an NZ sound reduction effect equal to or higher than that of the first embodiment. Also, when manufacturing the fan Ab, as in the first embodiment,
It has the advantage that it can be done easily and easily.

In the present invention, in addition to the above-mentioned embodiments, a plurality of blades arranged in a row in the axial direction of the rotary shaft in the state where the mounting angle phases are close to each other are used as blade rows. At this time, all of the plurality of blades forming each blade row may be arranged with different attachment angle phases.

That is, the angles formed by the blades on both sides of all the partition plates of the cross flow fan are not constant, but are different from each other. As a result, the arrangement phase angles of the blades are the same in any of the stations. It was designed so that it would not become. In this case, the ease of manufacture is inferior to that of each of the above-described embodiments, but since the phase of the NZ sound of each series is completely shifted, the effect of reducing the NZ sound becomes even more excellent.

[0045]

According to the first aspect of the present invention, each blade of the fan structure adjacent to each blade of one fan structure is moved to the clockwise direction or the counterclockwise direction by about 3 / of the angle between the blades. Since they are arranged with a significant phase difference of 10, it is possible to prevent the blade installation phase angles between the fan assemblies of the respective stations from being at the same position as much as possible, and in addition, of the blades of the adjacent stations. Unlike the case where the shift is small, the phase of the NZ sound can be effectively shifted.

Further, the NZ sound and the peak sound (2NZ sound, whose frequency is an integral multiple of the NZ sound) are larger than those of the conventional one, though the structure is easy and simple in that the angle between the blades in each train is shifted by a constant phase. 3NZ sound ...) can be reduced.

According to the second configuration of the present invention, when the inter-blade angle θ = 360 ° / z (where z is the number of blades in each series), the fan structure adjacent to each blade in one fan structure is used. Blades of (3/10) θ + α (where α ≦ (1 /
2n) · (360 ° / z), where n is the number of stations, the phase is shifted, so in addition to the effect of the first configuration, the rate of occurrence of secondary NZ sound Can be lowered to. Therefore, the NZ sound reduction effect equal to or higher than that of the cross flow fan according to the first configuration is achieved.

Further, at the time of manufacture, since the angles between the blades in the series are all the same, it is possible to set an optimum angle with a high air-blowing efficiency. Have.

According to the third aspect of the present invention, when a plurality of blades arranged in a row in the axial direction of the rotating shaft are arranged in a row in a state where the mounting angle phases are close to each other in the fan structure, Since all of the plurality of blades forming each blade row are arranged with different mounting angle phases, the phase of the NZ sound of each series is completely deviated, and the first and second configurations are provided. The effect of reducing the NZ sound is further improved.

As described above, according to the present invention, even if the present invention is applied to a multi-row cross flow fan having more than 10 stations, the blade mounting phase angles between the fan assemblies of the stations are set to the same position as much as possible. While it is possible to reduce the NZ noise by this, multiple blades in one fan structure are arranged at equal positions in the circumferential direction, and all blade angles are optimal. Since the angle can be set, it is possible to produce at low cost without lowering the efficiency of the blower at all, and it is possible to achieve excellent effects not seen in the past.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a cross flow fan equipped with a cross flow fan according to a first embodiment of the present invention.

FIG. 2 is a front view of the crossflow fan showing the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of the fan structure as seen from the axial direction.

FIG. 4 is a frequency characteristic diagram of noise generated by the cross flow fans of the comparative example and the first embodiment.

FIG. 5 is a front view of a cross flow fan showing a second embodiment of the present invention.

FIG. 6 is a perspective view showing an outline of a cross-flow blower equipped with a conventional cross-flow fan.

FIG. 7 is a partial front view thereof.

FIG. 8 is a partial front view of a cross flow fan showing a conventional example in which NZ noise reduction measures are taken.

[Explanation of symbols]

 11 Rotating shaft 12 End plate 13 Partition plate 14 Blade 15 Fan structure θ Angle between blades

Claims (3)

[Claims] 1. A plurality of partition plates made of discs having substantially the same diameter as the end plates are provided at predetermined intervals between the disc-shaped end plates disposed at both ends in the axial direction of the rotating shaft. The blades are arranged parallel to the end plates, and a unit number of blades are provided between the end plates and the partition plates facing the end plates and between the adjacent partition plates, and the outer edge of the blade is the outer edge of the end plate or the partition plate. The end plate and a partition plate facing the end plate or adjacent partition plates, and a plurality of fan structures composed of a plurality of blades, which are continuously arranged in the axial direction. A cross-flow fan consisting of, when the angle formed between the straight line connecting the center of the blade and the axis of rotation adjacent to each other in the circumferential direction in each fan structure is defined as the inter-blade angle, each blade of one fan structure Each blade of the fan structure adjacent to each other is a clock A cross flow fan, wherein the cross flow fan is mounted at a position shifted in phase by about 3/10 of the angle between the blades in a clockwise direction or a counterclockwise direction. 2. A plurality of partition plates made of discs having substantially the same diameter as the end plates are provided at predetermined intervals between the disc-shaped end plates arranged at both ends in the axial direction of the rotating shaft. The blades are arranged parallel to the end plates, and a unit number of blades are provided between the end plates and the partition plates facing the end plates and between the adjacent partition plates, and the outer edge of the blade is the outer edge of the end plate or the partition plate. The end plate and a partition plate facing the end plate or adjacent partition plates, and a plurality of fan structures composed of a plurality of blades, which are continuously arranged in the axial direction. And a blade-to-blade angle θ = 360 ° / z (where z: each of the stations) in each fan structure, which is formed between a straight line connecting between the center of the blade and the axis of rotation adjacent to each other in the circumferential direction. Number of blades), each blade of one fan structure Each blade adjacent the fan assembly against is in a clockwise or counterclockwise direction (3/1
0) θ + α (where α ≦ (1 / 2n) ・ (360 ° /
z), n: the number of stations) A cross-flow fan, which is mounted at a position shifted in phase. 3. A plurality of partition plates, which are discs having substantially the same diameter as the end plates, are provided at predetermined intervals between the disc-shaped end plates disposed at both ends of the rotary shaft in the axial direction. The blades are arranged parallel to the end plates, and a unit number of blades are provided between the end plates and the partition plates facing the end plates and between the adjacent partition plates, and the outer edge of the blade is the outer edge of the end plate or the partition plate. The end plate and a partition plate facing the end plate or adjacent partition plates, and a plurality of fan structures composed of a plurality of blades, which are continuously arranged in the axial direction. In the cross flow fan, the plurality of blades arranged in a row in the axial direction of the rotating shaft in a state where the mounting angle phases are close to each other in the respective fan structures are blade rows, and each blade row is Mounting angles for which all of the plurality of blades that are configured are different A cross flow fan characterized by being arranged in phase.