JP2001317494A - Centrifugal air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently enhance the total pressure of an air blower while reducing noise in a centrifugal air blower having plural blowoff ports. SOLUTION: Winding angles θ1 and θ2 of air passages 124 and 125 are set not less than 90 deg., and the ratio (G/D) of a gap dimension G to a fan diameter D is set not less than 0.1. Thus, an air flow is stabilized, and turbulence is hardly caused in the flow. Thus, the total pressure of the air blower 120 can be sufficiently enhanced while reducing the noise, and an NZ sound can be sufficiently reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal blower for blowing air taken in from the axial direction of a rotating shaft toward a radially outward direction, and is applied to an air purifier for a vehicle and a blower for an air conditioner embedded in a ceiling. It is effective.

[0002]

2. Description of the Related Art A centrifugal blower (hereinafter abbreviated as a blower) described in Japanese Utility Model Laid-Open No. 61-29222 is formed in a spiral shape outside a centrifugal multi-blade fan (hereinafter abbreviated as a fan). By providing a plurality of two air passages, air is blown out from a plurality of outlets simultaneously.

[0003]

However, as described in the above-mentioned publication, a blower having a plurality of outlets has a longer air passage length (air passage) than a blower having a single outlet. Is small, the air flow is unstable and the flow is likely to be disturbed. For this reason, noise is easily generated,
In addition, there is a problem that the total pressure of the blower cannot be sufficiently increased.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a blower having a plurality of outlets, in which noise is reduced and the total pressure of the blower is sufficiently increased.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there are provided a plurality of blades (122) around a rotation axis, and an axial direction of the rotation axis. Centrifugal multi-blade fan (121) that blows air sucked in from the outside toward the outside, and a plurality of fans that house the centrifugal multi-blade fan (121) and allow the air blown from the centrifugal multi-blade fan (121) to flow Spiral air flow paths (124, 12)
5) and a plurality of air passages (124, 12).
5) a scroll casing (123) having an air outlet (74b) on the downstream side of the air flow from the winding end (124b, 125b) of the spiral, and a plurality of air flow paths (1).
24, 125), the air flow path (124, 125)
Of the nose gap portions (124a, 125a) where the cross-sectional area of the flow path becomes the smallest, and the winding end portions (124b,
The winding angles (θ1, θ2) up to 125b) are not less than 90 °.

[0006] Thus, the air flow is stable, and the flow is hardly disturbed. Therefore, it is possible to sufficiently increase the total pressure of the centrifugal blower while reducing noise.

According to the second aspect of the present invention, the dimension (G) of the portion of the nose gap portion (124a, 125a) parallel to the radial direction of the centrifugal multi-blade fan (121) is determined by the centrifugal multi-blade fan (121). 121) is at least 0.1 times the diameter dimension (D).

This prevents the air blown out of the centrifugal fan (121) from periodically colliding with the nose of the scroll casing (123). ) Can reduce the noise (NZ sound) generated by periodically colliding with the nose portion.

According to the third aspect of the present invention, the centrifugal multi-blade fan (121) has a fan outlet angle (β) of the blade (122).
Is a backward vane fan larger than 90 °.

Thus, the dynamic pressure of the air blown from the centrifugal fan (121) is converted into a static pressure at a portion of the blade (122) from the air inlet side (inner diameter side) to the air outlet side (outer diameter side). Therefore, the total pressure can be more reliably increased.

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, a blower according to the present invention is applied to a vehicle air purifier for purifying air in a vehicle, and FIG. 1 shows a vehicle air purifier 100 as a rear package of the vehicle. FIG. 2 is a plan view showing a state where the air purifier is mounted on a tray 200. FIG. 2 is a sectional view taken along line AA of FIG.
1 is a perspective view of the interior of a vehicle equipped with 00.

In this embodiment, the air purifier 100 is used.
Is a smoke sensor (not shown) for detecting the degree of dirt.
The operation is started or stopped by an output signal of (1) or a manual switch (not shown) operated by an occupant.

In FIG. 2, reference numeral 110 denotes an air passage 111 inside.
The casing 112 is formed of a resin (polypropylene in the present embodiment) forming an air passage, and an inlet 112 for introducing vehicle interior air is formed on the air flow upstream side of the air passage 111,
On the other hand, on the downstream side of the air flow of the air passage 111, the inlet 1
Blows air introduced from 12 in two directions (multi-direction) 2
One outlet 113 is formed.

A suction grill 112a made of resin (in this embodiment, polypropylene) is attached to the inlet 112, and an outlet grill 113a made of resin (in this embodiment, polypropylene) is attached to the outlet 113. .

The inlet 112 in the air passage 111
The air blower 1 according to the present embodiment
The blower 120 sucks air from an inlet 112 and blows air toward two outlets 113. The details of the blower 120 will be described later.

In the air passage 111, the blower 120
On the more upstream side of the air flow, a rectangular dust filter 114 for removing dust in the air by a folded nonwoven fabric is provided, while on the downstream side of the air flow from the blower 120,
A rectangular deodorizing filter 115 for removing odor in the air by a porous material such as activated carbon attached to the honeycomb carrier is provided.

In the air purifier 100, as shown in FIG. 3, the intake grill 112a and the outlet grill 113a are exposed in the passenger compartment, and the other portions are in a trunk room 230 (FIG. 2).
The rear seat 210 and the rear window glass are arranged such that the blower 120 and the inlet 112 are located substantially at the center of the rear package tray 200 in the vehicle width direction, and the outlets 113 are located on both sides thereof. 220 is mounted on a rear package tray 200 provided between the rear package tray 200. The air blown out from each blowout port 113 is blown out toward the front upper side of the vehicle.

Next, the blower 120 will be described.

FIG. 4 is a top view of the blower 120 viewed from the inlet 112 side, and FIG. 5 is a sectional view taken along the line BB of FIG.
4 and 5, reference numeral 121 denotes a centrifugal multi-blade fan (hereinafter referred to as a fan) having a plurality of blades (blades) 122 around the rotation axis and blowing out air taken in from the axial direction of the rotation shaft outward. , Fan 121). In the present embodiment,
A rearward vane fan (turbo fan) having a blade outlet angle β of more than 90 ° is employed.

The fan exit angle β is the angle of intersection between the blade 122 and the outer diameter edge of the fan 121, as shown in FIG.

Reference numeral 123 denotes a plurality of (two in the present embodiment) spiral first and second air passages 124 and 125 through which the fan 121 is housed and through which air blown from the fan 121 flows. And the first and second air passages 1
24, 125 spiral end 124b, 125b
A scroll casing (hereinafter, abbreviated as a casing) having outlets 124c and 125c on the downstream side of the air flow.
And the winding angles θ1 and θ2 of both air flow paths 124 and 125
Is set to be 90 ° or more (120 ° in the present embodiment).

Here, the winding angles θ1 and θ2 are defined as the nose gap portions 124a and 125a (the centers of the radii of curvature of the nose portions N1 and N2 and the rotation of the fan) where the cross-sectional area of the air channels 124 and 125 is the smallest. Reference line L connecting the center
The angle from 1) to the winding end portions 124b and 125b (the reference line L2 connecting the rotation center of the fan).

In FIG. 5, reference numeral 126 denotes an electric motor (drive means) for rotating the fan 121, 127 denotes a suction port of the casing 123, and guides air to the fan 121 to the outer edge of the suction port 127. A bell mouth 128 is provided.

Next, the features of this embodiment will be described.

According to this embodiment, both air flow paths 124,
Since the winding angles θ1 and θ2 of 125 are as long as 90 ° or more, the air flow is stable and the flow is hardly disturbed. For this reason,
The total pressure of the blower 120 can be sufficiently increased while reducing noise.

The fan 121 has a fan exit angle β of 9
Since it is a backward vane fan larger than 0 °, the fan 12
The dynamic pressure of the air blown from 1 is converted to a static pressure at a portion from the air inlet side (inner diameter side) of the blade 122 to the air outlet side (outer diameter side). Therefore, even if the winding angle θ of the casing 123 is as small as less than 180 °, the static pressure can be increased, and the total pressure can be more reliably increased.

FIG. 6 is a test result showing the relationship among the winding angle θ and the air volume Va, the specific noise ks and the efficiency η.
a, the specific noise ks, and the efficiency η are the same as those of the prior art (the winding angle θ =
65 °).

Incidentally, the efficiency η is the ratio of the product of the air volume Va and the total pressure DPt to the power consumption W of the electric motor 126 (Va
× Dpt / W), the air volume Va and the total pressure D
The terms Pt and specific noise Ks are defined in JIS B 01
The test method is based on JIS B 834.
0.

Meanwhile, in the nose portions N1 and N2, noise (hereinafter, this noise is referred to as NZ sound) is generated by the air blown from the fan 121 periodically colliding with the nose portions N1 and N2. Incidentally, the frequency of the NZ sound is substantially proportional to the rotation speed of the fan 121 and the number of blades 122.

Therefore, in order to reduce the NZ sound, the dimensions of the nose gap portions 124a and 125a (hereinafter, referred to as gaps) of the nose gap portions 124a and 125a so as to prevent air blown from the fan 121 from colliding with the nose portion. It is desirable to increase the dimension G.). However, since the winding start and the winding end of the air flow paths 124 and 125 communicate with each other at the nose gap portions 124a and 125a, if the gap dimension G is excessively increased, the efficiency of the blower 120 is deteriorated.

The inventors of the present invention have confirmed the relationship between the gap size G and the specific noise ks by a test. As shown in FIG.
It has been confirmed that when the value is 0.1 times or more, the NZ sound can be sufficiently reduced. Incidentally, in the present embodiment, the gap dimension G is set to 0.1 times the diameter dimension D of the fan 121.

FIG. 8A is a test result showing the noise level (SPL) when G / D = 0.06.
FIG. 8B is a test result showing the noise level when G / D = 0.1. As is clear from FIG.
It can be understood that the noise level can be reduced if is set to 0.1 or more.

The terms of the noise level (SPL) are defined according to JIS B 0132, and the test method is based on JIS B 8340.

(Other Embodiments) In the above embodiment, the number of outlets 124c and 125c of the blower 120 is two. However, the present invention is not limited to this, and as shown in FIGS. The present invention can also be applied to an apparatus having three or more outlets.

Further, in the above-described embodiment, the blower according to the present invention is applied to an air purifier for a vehicle, but the present invention is not limited to this, and may be applied to other devices such as an air conditioner embedded in a ceiling. Can also be applied.

Further, in the above-described embodiment, the rearward vane fan having the fan outlet angle β larger than 90 ° is used, but a forward vane fan having the fan outlet angle β of 90 ° or less may be used.

[Brief description of the drawings]

FIG. 1 is a plan view of an air purifier using a blower according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of the interior of a vehicle equipped with the air purifier of FIG. 1;

FIG. 4 is a top view of the blower according to the first embodiment of the present invention.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is a graph showing a relationship between a winding angle θ, an air volume Va, a specific noise ks, and an efficiency η.

FIG. 7 is a graph showing a relationship between a ratio between a gap dimension G and a fan diameter D and a specific noise ks.

FIG. 8 is a graph showing a relationship between a ratio between a gap dimension G and a fan diameter D and a noise level (SPL).

FIG. 9 is a top view of a blower according to a modification of the present invention.

FIG. 10 is a top view of a blower according to a modification of the present invention.

[Explanation of symbols]

120: centrifugal blower, 121: centrifugal multi-blade fan, 1
22: blade (wing), 123: scroll casing, 124, 125 ... air flow path, 124a, 125a ...
Nose gap part, 124b, 125b ... winding end part, 124c, 125c ... outlet, N1, N2 ... nose part.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H034 AA02 AA18 BB06 CC03 DD09 DD12 DD24 DD25 DD28 EE06 EE08 3H035 DD05

Claims (3)

[Claims] 1. A centrifugal multi-blade fan (121) having a large number of blades (122) around a rotation axis and blowing out air taken in from the axial direction of the rotation shaft toward a radially outward direction; While storing the multi-blade fan (121),
A plurality of spiral air flow paths (124, 125) through which air blown from the centrifugal multi-blade fan (121) flows.
And the plurality of air passages (124, 12
5) a scroll casing (123) having an air outlet (74b) on the downstream side of the air flow from the winding end portion (124b, 125b) of the spiral. In the plurality of air flow paths (124, 125), The winding angles (θ1, θ2) from the nose gap portions (124a, 125a) to the winding end portions (124b, 125b) in the air flow channels (124, 125) where the flow channel cross-sectional area becomes the smallest are 90 ° or more. A centrifugal blower, characterized in that: 2. The nose gap section (124a, 12a).
5a), the dimension (G) of a portion parallel to the radial direction of the centrifugal multi-blade fan (121) is at least 0.1 times the diameter dimension (D) of the centrifugal multi-blade fan (121). The centrifugal blower according to claim 1, wherein: 3. The centrifugal multi-blade fan (121) is a backward vane fan having a fan outlet angle (β) of the blade (122) larger than 90 °. The centrifugal blower as described.