JPS61200397A - Blower - Google Patents

Abstract

PURPOSE:To make the captioned fan compact by providing a disc-shaped wind passage member in a volute casing in such a manner as said member is opposed to an impeller at a predetermined interval and setting a starting point of the volute of the volute casing in a position beyond 80 deg. as an angle in the direction of rotation of an impeller, from a reference line that is the direction of a blowoff point. CONSTITUTION:A motor 2 is fitted on a disc-shaped wind passage member 5 and fixed to a volute casing 7 by means of a support metal fitting 9. Further, when an angle measured, from a reference line that is the direction of a blowoff port 3, in the direction of rotation of an impeller 1 of a propeller fan, up to a starting position of the volute of the volute casing 7, is theta, theta is a little over 90 deg. to show a very particular shape of the fan. Due to this, the fan can be considerably miniaturized. Furthermore, when the radius of the volute at the start of spiraling is R1 radium thereof at a position advancing by 180 deg. from the position of start is R2, depth of the casing 7 is L1, outside diameter of the wind passage member 5 is D2 the interval between the side plate of the volute casing 7 and the wind passage member 5 is L2, a fan having those amounts within the limits satisfying the formula 0.6<=R1/D1<=0.8,1.4<=D2/ R1<=1.7,0.45<=L2/L1<=0.65 brings about good performance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an air blower, and more particularly to an improvement in the form of a blowing flow from a propeller fan equipped with a swirl chamber casing.

[Conventional technology]

The most basic invention is JP-A-58-77200. This has improved performance by forming a centrifugal diffuser air path with a disc and a disc ring on the blowing side of the propeller fan, and the specific noise level Ks (which represents the overall performance of the blower's aerodynamic performance and noise characteristics) Noise level per unit air volume/wind pressure, even if the noise level is the same,
If the wind volume and wind pressure increase, this value will become smaller. ), the noise can be reduced by 5 to 10 dB (A).

Furthermore, in order to make this basic invention applicable to a wider range of applications, the centrifugal diffuser is equipped with a swirl chamber casing for consolidating the fluid blown out from the entire circumference of the air passage in only one direction. Showa 58-77200
Utility Model Application No. 5917690 is an invention that takes advantage of the structure of the propeller fan of No. FIG. 10 shows a conventional example of a propeller fan with a spiral chamber casing as disclosed in this invention (Utility Application No. 17690/1983).

FIG. 10(a) is a longitudinal sectional view, and FIG. 10(b) is a sectional view taken along line nu in FIG. 10fa). In fig.

(1) is a propeller fan impeller that boosts pressure and blows air.

(2) is a motor that drives the propeller fan impeller (1).

(3) is the propeller fan impeller (the air outlet perpendicular to the rotation axis of +1), (4) is the propeller fan impeller (the duct for guiding air to 11) (4a) and the air outlet side of (4a) A duct casing formed by an air passage member (4b) provided from the end face, (5) is a disc-shaped air passage member,
The air passage member (4b) forms a centrifugal diffuser air passage (6). (7) is a spiral chamber casing for collecting the flow in one direction of the outlet (3) and at the same time recovering pressure, and a free air passage (8) is provided between it and the disc-shaped air passage member (5) is forming. Reference numeral (9) denotes a support fitting for fixing the disk-shaped air passage member (5), and in this example, it is connected to the swirl chamber casing (7).

The conventional example is constructed as described above, and the difference from the spiral casing used in general centrifugal fans is that the free air path (
8) was established. The flow direction of the fluid blown out from the centrifugal diffuser air passage (6) is substantially radial, with fewer two-circumferential components, compared to the flow caused by the centrifugal fan.

Therefore, if there is no free air passage (8), a considerably large spiral chamber casing must be used, or the air volume distribution will be biased in the circumferential direction, resulting in poor fan performance. By providing .

Whirlpool casing with a small proportion (portion where the discharge air volume ratio is low and static pressure is high (near the beginning of the spiral)
As a result, a flow is generated in the free air path (8) toward the part where the discharge air volume ratio is high and the static pressure is low (near the end of the spiral), so the bias in the circumferential direction of the air volume distribution is improved, and the fan performance is improved. Helps prevent deterioration.

[Problem that the invention seeks to solve]

Although the conventional example has the above characteristics, the outer shape of the spiral chamber casing (7) still follows the spiral chamber shape of a general centrifugal fan.

The blowout flow condition peculiar to propeller fans and the free air path (8) shown in the basic invention (Japanese Unexamined Patent Publication No. 58-77200)
The shape of the spiral chamber is not optimal (minimum size possible and has good fan performance), taking into consideration the flow of the special air path. In addition, the conventional example has a complex structure that aims to improve performance by combining the pressure recovery functions of both the centrifugal diffuser air path (6) and the vortex chamber casing (7), so the most important disc-shaped air path member ( Although the optimum values of the fixing position and size of 5) are significantly different from those of the basic invention (Japanese Patent Application Laid-open No. 77200/1983), almost no settings have been made regarding these optimum values. Therefore, although the unique structure with the free air passage (8) has ensured fan performance and made the fan more compact to a certain extent, it is still insufficient, and the flow of such a special propeller fan There was a strong need to further significantly improve fan performance and make the fan more compact by devising a suitable spiral chamber shape and conducting detailed studies on the dimensions of each part.

This invention was made in response to the above-mentioned needs.
The purpose of the present invention is to obtain a propeller fan equipped with a swirl chamber casing that can be significantly more compact than the conventional example and has good fan performance.

[Failure to solve the problem]

The blower according to the present invention has a propeller fan impeller driven by a motor arranged inside a duct casing, and a spiral casing connected to the outlet end of the duct casing and having an air outlet in a direction perpendicular to the rotation axis. A disc-shaped air passage member is provided in the spiral chamber casing so as to face the propeller fan impeller at a predetermined interval, and the spiral winding start of the spiral chamber casing is based on the direction of the air outlet. The position is set at an angle of 80° or more in the direction of rotation of the impeller.

Furthermore, we conducted a detailed study on the starting radius of the spiral, the optimal range of the size and fixing position of the disc-shaped air passage member, the relationship between the expansion ratio and depth dimension of the spiral chamber casing, and the lower limit of the expansion ratio. The shape and dimensions of each part are set.

[Effect]

In this invention, since the spiral chamber casing has a very specific spiral winding start position, it can be significantly downsized for the same expansion ratio. In addition, the optimum range of shape and dimensions of each part is experimentally determined and set in detail, so the best fan performance can be obtained, and the limits of miniaturization can also be ascertained.

[Embodiments of the invention]

An embodiment of this invention is shown in FIG. FIG. 1(a) is a longitudinal sectional view, and FIG. 1(b) is a sectional view taken along line 1-1 in FIG. 1(a). The components (1) to (9) basically have the same role as the above-mentioned conventional example.

The shape of the volute chamber casing (7) and the dimensions of each part vary widely. In order to explain the difference from the conventional example in an easy-to-understand manner, the dimensions of each part are shown in symbols in Figure 2. The propeller fan impeller (
1) Measured in the direction of rotation. The angle to the spiral winding start position of the spiral chamber casing (7) is θ, the outer diameter of the propeller fan impeller (]) is D12, and the outer diameter of the disc-shaped air passage member (5) is D2. R1 is the radius at the beginning of the spiral winding of the spiral chamber casing (7) + R2 is the radius of the spiral shape at a position 180° ahead of this winding start position, and R2 is the radius at the beginning of the spiral winding of the spiral chamber casing (7).
The depth dimension of the spiral chamber casing (the distance between the side plate of the force and the disc-shaped air passage member (5) is L2°) The maximum radial dimension of the swirl chamber casing (the maximum radial dimension of the force is W2 from the rotation axis to the air outlet (3)
The dimensions up to the point are indicated by H, respectively. Vortex chamber casing (For the spiral shape of the force, shapes such as logarithmic helical lines and Archimedean helical lines are used, but if 1'L2/lh is used as a parameter representing the expansion ratio, the spiral shape of the spiral can be adjusted to some extent. The characteristics of the blower can be evaluated regardless of the differences.

The most significant feature of this embodiment is the shape of the vortex chamber casing (7), which has a very special shape in which the angle θ defined above is, for example, a little over 90° in this embodiment. Generally, the angle θ of a spiral chamber casing used in a centrifugal fan or the like is about 0° at most. This is because if the angle θ is made larger than this, the aerodynamic performance and noise characteristics will deteriorate rapidly, and this is closely related to the exit flow of the impeller of the centrifugal fan. However, like the special propeller fan used in the embodiment of this invention,
If the flow blown out from the impeller is oriented in a fairly radial direction, the angle θ of the volute chamber casing (7) should be set to a little over 90°, which is the minimum dimension W representing the size of the fan. Experiments have revealed that even if several types are changed, the specific noise level KS, which is the overall performance of the fan, does not change much as long as the expansion ratio R2/几1 remains the same. Therefore,
By forming a special spiral chamber casing shape with an angle θ of more than 90° as in the embodiment shown in FIG. 1, the external shape can be made significantly more compact without changing the fan performance. In order to clearly show the effect of compactness, the enlargement ratio R2/R1 is kept the same as in the embodiment shown in Fig. 1, and the starting position of one winding is changed from the angle θ of the conventional example shown in Fig. 10.
Fig. 2 shows the shape of the spiral chamber casing (7) in the case of . In the case of FIG. 2, the dimension W representing the size of the fan is 30% larger than that of the embodiment of FIG. 1. For reference, FIG. 3 shows how much the dimension W, which represents the size of the fan, increases when the angle θ is varied. Conversely, when the 9th dimension W is the same, the angle θ
By increasing R2/R1, the fan performance can be improved. Figure 4 shows the effect on the specific noise level when the angle θ is changed in several ways under the same condition of the 9th dimension W.

A typical example of experimental results evaluated by the amount of reduction ΔKS from a certain standard specific noise level is shown. As is clear from the figure, it can be seen that when the angle θ is set to 80° or more, the specific noise level, which is the overall performance of the fan, is considerably improved. In this case, when the angle θ is 80° or more, the improvement amount does not change because the fan performance deteriorates somewhat due to the angle θ being too sharp, and the performance improvement amount due to the increase in the expansion ratio R2/R+ This is because it acts to partially cancel out.

Note that if the dimension H from the 9 rotation axis to the air outlet (3) is about the radius of the 9 disc-shaped air passage member (5), it will hardly affect the fan performance.

Now, not only the shape of the swirl chamber casing (7) as described above, but also its size and other dimensions affect the performance and size of the fan. Therefore.

Spiral-shaped winding start radius R4 + disc-shaped air passage member (5)
The outer diameter D2. Figures 5, 6, and 7 show the results of an experimental study on the influence of the distance L2 between the side plate of the swirl chamber casing (7) and the disc-shaped air passage member (5) on fan performance, respectively. Shown below. These comparisons were made under the same conditions for the dimension W, which represents the size of the fan, with respect to the spiral shape of the embodiment shown in Figure 1, in which the angle θ is over 90 degrees, and each dimension is also the most relevant. It is shown dimensionless in the deep dimension. As is clear from these results, 0.6≦R
t/Dt≦0.8°1.4≦D2/R1≦1.7.0.
Fan performance is good in the range of 45≦L2/L1≦065.
It can be seen that outside this range, the fan performance deteriorates significantly. In particular, 063≦1'Li /n1≦0.75.
1.45≦D2/R+≦165.0.5≦L2/L1
It can be seen that almost the best fan performance can be obtained anywhere within the range ≦06. The size of the volute chamber casing (7
) expansion ratio R2/R1 and depth dimension L1/1)+
FIG. 8 shows the results of an experimental study on the influence of the relationship (lL2L1)/(R+D+) + and the value of the expansion ratio R27R1 itself on fan performance.

It is shown in FIG. From these results, (TL2L1)
, /(RIDl)≧0.6. It is clear that unless lt2/Q≧1°5, the fan performance will deteriorate rapidly. In addition.

Although the above optimum range is different from the range shown in the basic invention (Japanese Unexamined Patent Publication No. 58-77200), the pressure recovery function of the present invention is
This is because it is located not only in the centrifugal diffuser air passage (6) but also in the volute chamber casing (7).

This is a reasonable result.

By the way, in the above embodiment, the motor (2) is attached to the disc-shaped air passage member (5), and the disc-shaped air passage member (5) is fixed to the spiral chamber casing (7) using the support fitting (9). is shown, but the motor (2) and the disc-shaped air duct member (
5) Since the structure of the mounting structure is not directly related to the content claimed by the present invention, the same effect can be expected even if the structure is the mounting structure other than that of the present embodiment. Further, the same effect can be expected even if the shape of the suction side of the duct casing (4) is a shape other than that of this embodiment for the same reason.

〔Effect of the invention〕

As explained above, this invention can be made considerably more compact by making the shape of the spiral chamber casing into a special shape that has never been used before, in which the angle θ at the start position of the spiral is more than 80 degrees. It has the effect of being able to.

Furthermore, by optimizing the shape and dimensions of each part, it is possible to improve fan performance, and at the same time, it is also possible to determine the limits of compactness, which has the effect of increasing the efficiency of fan design.

[Brief explanation of drawings]

FIG. 1(a) is a longitudinal sectional view showing one embodiment of the present invention. Fig. 1(b) is a sectional view taken along the line 1-1 in Fig. 1(a), Fig. 2 is a sectional view showing the size of the spiral chamber casing of a conventional blower, and Fig. 3 is an embodiment of Fig. 1. Figure 4 is a characteristic diagram showing the relationship between the angle θ at the start of the spiral winding of the spiral chamber casing and the dimension W representing the size of the spiral chamber casing. FIG. 5 is a characteristic diagram showing the relationship with fan performance. 6, 7, 8, and 9 are characteristic diagrams showing the relationship between the shape and dimensions of each part and fan performance in the embodiment shown in FIG.
Figure (a) is a longitudinal sectional view showing a conventional blower. FIG. 10(b) is a sectional view taken along line nn of FIG. 10(a). In the figure, (1) is the propeller fan impeller, (2) is the motor, (3) is the air outlet, (4) is the duct casing,
(5) is a disc-shaped air passage member, and (7) is a swirl chamber casing. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A propeller fan impeller that is rotationally driven by a motor to perform a blowing action, a duct casing for guiding air to the propeller fan impeller, and a rotating shaft of the propeller fan impeller connected to the outlet end of the duct casing. a spiral chamber casing having an air outlet in a direction perpendicular to the axis of rotation, and having a spiral outer shape in a cross section perpendicular to the rotational axis; The winding start of the spiral of the spiral chamber casing is at an angle of 80 degrees relative to the direction of rotation of the propeller fan impeller with respect to the direction of the air outlet of the spiral chamber casing.
A blower characterized by being located at a position of at least 100 degrees. (2) The outer diameter of the propeller fan impeller is D_1, the outer diameter of the disc-shaped air passage member is D_2, the radius of the spiral start of the spiral chamber casing is R_1, and 180 degrees from this winding start position.
If the radius of the spiral at the advanced position is R_2, the depth of the spiral chamber casing is L_1, and the distance between the side plate of the spiral chamber casing and the disc-shaped air passage member is L_2, then 0.6≦R
_1/D_1≦0.8, 1.4≦D_2/R_1≦1.
7, 0.45≦L2/L1≦0.65, (R_2L_1
)/(R_1D_1)≧0.6, and R_2/R_1
The blower according to claim 1, characterized in that ≧1.5.