JP4611333B2 - Side cut fan - Google Patents

Description

  The present invention relates to a venturi wind tunnel shape of an axial fan, particularly a side cut fan.

JP 2004-353585 A)

As seen in the above-mentioned patent document, in order to cope with the conflicting elements of improvement in air blowing performance and calming, various studies have been tried on the venturi shape of the venturi, and the mounting space according to the present invention has been put into practical use. The so-called side cut fan intended to be suppressed is still in the applicable range.

The side cut fan itself also has the purpose of maintaining rigidity as a countermeasure for thinning of the venturi associated with the formation of the cut portion, and the venturi inner peripheral surface forming the wind tunnel has the initial wind tunnel outer arc surface at the cut portion. As is well known, it is formed so as to have a curvature diameter different from the arc diameter of the propeller so as to communicate with the rotating outer peripheral arc surface of the propeller with less change in the gap.

However, in the side cut fan, as described above, in addition to the improvement effect of the prior art, the arc diameter of the inner peripheral surface of the venturi corresponding to the side cut portion is the initial arc diameter that forms the original wind tunnel outer arc surface. There is a demand for countermeasures against the influence of pressure fluctuations by forming the arc diameter different from that of the arc.

In the side cut fan according to the present invention, an arc diameter communicating portion communicating with an initial arc diameter and a different arc diameter is formed on an inner surface of a portion corresponding to a predetermined cut portion on the outer peripheral surface of the venturi, and in the circumferential direction. The displaced part also includes another additional arc diameter communicating portion that communicates with the initial arc diameter and a different arc diameter,

The additional arc diameter communicating portion is provided at two other locations of the portion shifted 90 degrees with respect to the initial two excised portion forming portions,

Different arc diameters communicating with the initial arc diameter on the inner peripheral surface of the venturi are all formed as the same arc diameter.

The side cut fan according to the present invention is a unique problem in the side cut fan, because of the change in the gap between the outer peripheral circular arc surface of the propeller and the change in the circular arc diameter of the outer peripheral surface of the wind tunnel due to the cutting of the outer peripheral surface of the venturi. The effect of suppressing the influence of pressure interference between the propeller and the outer peripheral surface of the wind tunnel is realized.

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

FIG. 1 is a front view showing a first embodiment of the present invention, and FIG. 2 is a front view showing an embodiment of the prior art. In contrast to the conventionally known side-cut fan 1 with the two surfaces shown in FIG. 2 cut away, in FIG. 1, a 90-degree change is made together with the arc-diameter communicating portion 3-1 formed on the arc-shaped outer arc surface of the side-cut portion 2-1. The additional arc diameter communicating portion 3-4 is provided on the outer arc surface of the wind tunnel at the portion, and the arc diameter communicating portion having a large curvature diameter with respect to the initial perfect circular wind tunnel outer arc surface 3-2 is additionally formed. The effect of calming is enhanced by minimizing the change of voids during turning.

1 is similar to that of FIG. 2 on the outer peripheral surface of the venturi 2, but as described above, it is formed on the inner peripheral surface of the venturi 2 at a position shifted 90 degrees from the side cut portion 2-1. The additional arc diameter communicating portion 3-4 is additionally shown as an example.

In general, the two side cut portions 2-1 as the side cut fan 1 are often provided at opposing portions with a shift of 180 degrees, and a corresponding arc diameter communication portion having a different curvature diameter is added. It can be said that it is common to make a 90-degree mutation with the two side-cut portions 2-1.

FIGS. 3 and 4 show the conventional structure shown in FIG. 2 and the two shown in FIG. 1 according to the configuration of the side cut fan 1 in which the side cut part 2-1 illustrated in FIGS. FIG. 6 is a comparison data showing the air flow performance and the overall noise value in the configuration to which the additional arc diameter communication part 3-4 is added, and the comparison data showing both noises as frequency analysis.

In the embodiment of the present invention configuration shown in FIG. 1 described above, a significant reduction effect of the noise level in the high air volume region can be confirmed by the overall noise value shown in FIG. 3, and the frequency analysis data of FIG. Among the noise peak values generated in this cycle, a reduction effect at 800 Hz, which shows the maximum value, was confirmed, and it contributed to the reduction in the overall value.

The side cut fan according to the present invention suppresses noise due to the influence of pressure interference caused by the change in the gap between the outer peripheral arc surface and the wind tunnel outer arc surface during propeller rotation without deriving an increase in mounting space. Therefore, it is possible to expand the application of the side cut fan as a space-saving axial fan.

It is explanatory drawing which looks at the venturi front of the example of the side cut fan which concerns on this invention. It is explanatory drawing which looks at the venturi front of the example of the side cut fan used as a prior art. It is the comparison data in the overall of the noise in the example of FIG. 1 and the example of FIG. FIG. 4 is comparison data showing a frequency analysis result in the data of the example of FIG. 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Side cut fan 2 Venturi 2-1 Side cut part 3 Wind tunnel 3-1 Arc diameter communicating part of side cut part inner surface 3-2 Initial wind tunnel outer side arc surface 3-3 Wind tunnel inner side arc surface

Claims (2)

An axial fan having a cylindrical venturi that forms a wind tunnel on the inside and a propeller disposed in the wind tunnel. In a side cut fan having a flat side cut portion, an arc surface that guides the flow of air, except for the side cut portion, continues in the circumferential direction on the inner peripheral surface of the opening in the venturi. The side cut fan is characterized in that a portion where the gap with the propeller is narrowed is formed at a predetermined position away from the side cut portion in the circumferential direction of the continuous arc surface. . The side cut portions are provided at two locations facing each other at 180 degrees in the venturi, and a portion of the continuous arcuate surface where the gap with the propeller is narrowed is 90 degrees in the circumferential direction with respect to the side cut portions. The side cut fan according to claim 1, wherein the side cut fan is formed at a portion to be changed .

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