JPH1137096A - Blower unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower unit that can be miniaturized while being high in air blasting efficiency. SOLUTION: A scroll 23 formed from a tongue part 26 to a discharge port 29 of a blower unit l is formed of a first scroll 23a formed at a first expansion ratio with a large expansion angle, and a second scroll 23b formed at a small expansion ratio. The change in the expansion ratio from the start part of the scroll 23 to a specified position can therefore be made large, and the expansion ratio from the specified position to the vicinity of the discharge port 29 can be suppressed, so that the vicinity of the discharge port 29 can be made small, and air speed distribution near a blowoff port becomes excellent so as to heighten discharge pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower unit used for a vehicle air conditioner.

[0002]

2. Description of the Related Art As a conventional blower unit, Japanese Patent Publication No.
Japanese Patent Application Laid-Open No. 292079/1990 discloses a centrifugal blower having a scroll casing, in which when a first ventilation outlet is opened, a divergence angle of an air passage for ventilation is increased, and a second blowing for heating is performed. When the outlet and the third air outlet for defrosting are opened, an air path divergence angle increasing / decreasing means for reducing the divergence angle of the air path is provided, whereby the maximum fan efficiency according to the airflow resistance of the air conditioner is increased. The divergence angle of the air path can be set to the generated divergence angle of the passage.

[0003] Japanese Patent Application Laid-Open No. 1-179898 discloses a centrifugal blower having a spiral ventilation path, in which the winding angle is varied in accordance with the ventilation resistance when suction or discharge is performed by a centrifugal fan. In addition, a variable means for varying the spread angle over the entire winding angle is provided.

[0004]

However, in the centrifugal blower according to the above-mentioned reference, it is necessary to provide variable means for changing the spread angle, and the size of the centrifugal blower is reduced to the size when the spread angle is maximum. In particular, there has been a problem that the air conditioner needs to be downsized, and in particular, there has been a problem of downsizing of the blower unit due to a demand for downsizing of the air conditioner, and a decrease in blowing efficiency due to downsizing.

In the scroll shape, logarithmic scrolling with a logarithmic spreading angle is slightly more efficient than proportional scrolling with a proportional spreading angle. In such a case, there is a problem that the spreading ratio becomes too large as approaching the discharge port. In addition, according to the results of visualization experiments of the flow in the scroll, it is found that there is a portion that does not partially match the wind flow in the scroll. Was.

[0006] Therefore, an object of the present invention is to provide a blower unit which achieves downsizing and has high air blowing efficiency.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a multi-blade fan having a plurality of blades, an inlet opening on a side of the multi-blade fan in a rotation axis direction, and An outlet formed at a predetermined position, a tongue formed at a base of the outlet and closest to the multi-blade fan, and formed from the tongue to the outlet along a rotation direction of the multi-blade fan. In a blower unit comprising a scroll having a first scroll formed at a first spreading ratio from the tongue portion to a predetermined winding angle position, and a scroll extending from the predetermined winding angle position to the air outlet. A second scroll formed at a second spread rate smaller than the first spread rate.

Therefore, according to the present invention, the scroll formed from the tongue of the blower unit to the discharge port is formed at the first spread ratio having a large spread angle.
And a second scroll having a small spread ratio, the change in the spread ratio from the scroll start portion to the predetermined position can be increased, and the spread ratio in the vicinity of the discharge port from the predetermined position can be suppressed. Therefore, it is possible to reduce the size in the vicinity of the discharge port and to improve the wind speed distribution in the vicinity of the outlet to increase the discharge pressure, thereby achieving the above object.

Specifically, the first scroll is a logarithmic scroll that increases at a logarithmic spread angle (a scroll that expands at a logarithmic spread rate as indicated by L1 in FIG. 3), and the second scroll is a proportional spread angle. It is desirable to use a proportional scroll (a scroll that spreads at a constant spreading rate shown in FIG. 3R1), and the first scroll is a first logarithmic scroll that increases at a first logarithmic spreading angle (see FIG. 3R1). L1), and the second scroll is a second logarithmic scroll that increases at a second logarithmic divergence angle smaller than the first logarithmic divergence angle (L2 in FIG. 3). Scrolling with a logarithmic spreading rate as shown) is also good.

[0010]

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

The blower unit 1 shown in FIG. 1 and FIG.
The multi-blade fan 4 is mounted on a vehicle air conditioner and includes a multi-blade fan 4 and a motor 3 for rotating the multi-blade fan 4.

The motor 3 is usually a brushless motor, and has a housing 33 in which a printed circuit board is housed, a stator (not shown) formed so as to protrude from the housing 33, and a rotating magnetic field generated in the stator surrounded by the stator. And a rotating shaft 31 to which the rotor 32 is fixed.

The multi-blade fan 4 includes a boss 41 fixed to the rotating shaft 31, a cone 42 extending from the boss 41, and a plurality of blades 44 erected on the outer peripheral edge of the cone 42. And a holding ring portion 4 for fixing an upper end of the blade portion 44.
3 D is the diameter of the multi-blade fan 4.

The case 2 includes an upper surface portion 21 and a lower surface portion 22 formed at both ends of the multi-blade fan 4 in the direction of the rotation axis.
And an outer wall 24 and an inner wall 25 forming side portions of the outlet 29, and a tongue 2 formed at a base of the inner wall 25.
6 and a scroll 23 continuously provided from the tongue portion 26 to the base end of the outer wall portion 24, and a suction port 28 is formed in the upper surface portion 21.
The width of the discharge port 29 is gradually increased from the gap between the tongue 26 and the multi-blade fan 4 along the rotation direction of the multi-blade fan 4.
It is an airway leading to

The scroll 23 is composed of a first scroll 23a between θ0 and θ1 and a second scroll 23b between θ1 and θ2. The first scroll 23a is formed by a logarithmic spreading ratio represented by the following mathematical expression 1. Incidentally, what is indicated by S in FIG. 2 indicates the beginning of the scroll.

[0016]

DR / dθ = (D / 2) · θ · tan β · exp
(Θtan β)

In Equation 1, R is the distance from the center of the multi-blade fan 4 to the scroll 23, θ is the winding angle (deg), D is the diameter of the multi-blade fan, and β is This is the scroll spread angle (deg). Expression 1 is obtained by differentiating Expression 2 below for calculating the diameter R of the logarithmic scroll with the winding angle θ.

[0018]

R = (D / 2) exp (θtan β)

Further, in the first embodiment, the second scroll 23b is formed with a proportional spread shown by the following equation (3).

[0020]

DR / dθ = (π / 180) · D · tan α = C

In Equation 3, R is the distance from the center of the multi-blade fan 4 to the scroll 23, θ is the winding angle (deg), D is the diameter of the multi-blade fan, and α is The scroll spread angle (deg), and C is a constant. Further, Expression 3 is obtained by differentiating Expression 4 below for calculating the diameter expansion R of the proportional scroll with the winding angle θ.

[0022]

R = (D / 2) + (πθ / 180) Dtan α

As a result, as shown in FIG. 3, the scroll 23 is rotated from the winding angle θ1 to the winding angle θ2 by the logarithmic spreading ratio indicated by L1 from the winding angle θ0 to the winding angle θ1.
2 by forming with the proportional spread rate shown by
In this case, it is possible to reduce the size of the scroll compared to the scroll based only on the logarithmic spreading ratio indicated by the broken line. In addition, the distribution of the wind speed blown out from the discharge port 29 can be improved, so that the discharge pressure can be increased.

Further, the second scroll 23b is
In the second embodiment, it is formed by the logarithmic spreading ratio represented by Expression 5.

[0025]

DR / dθ = (D / 2) · θ · tan γ · exp
(Θtan γ)

In Equation 3, R is the distance from the center of the multi-blade fan 4 to the scroll 23, θ is the winding angle (deg), D is the diameter of the multi-blade fan,
γ is a scroll spread angle (deg), and β has a relation of β> γ.

As a result, as shown in FIG. 3, the scroll 23 is rotated from the winding angle θ1 to the winding angle θ2 by the logarithmic spreading ratio L1 from the winding angle θ0 to the winding angle θ1.
2 by forming with the logarithmic spreading ratio shown in FIG.
In this case, it is possible to reduce the size of the scroll by using only the logarithmic spreading ratio indicated by the broken line. In addition, since the rate of change between the tongue 26 and the winding angle θ1 is increased, the air volume can be secured, and the winding angle θ1 can be secured.
Since the distribution of the wind speed blown out from the discharge port 29 can be improved as shown in FIG. 4 by reducing the rate of change from the pressure, the discharge pressure can be increased, and the blowing efficiency can be improved.

FIG. 5 shows the relationship between the air volume and the discharge pressure in the case of logarithmic scrolling and proportional scrolling, where Lt1 is a logarithmic scroll having a divergence angle of 7 °, Lt1.
2 is for logarithmic scrolling with a divergence angle of 7.5 °, Lt3 is for logarithmic scrolling with a divergence angle of 8 °, and Rt1 is for proportional scrolling with a divergence angle of 11 °. For this reason,
When a predetermined scroll angle is formed by a logarithmic scroll having a divergence angle of 7.5 °, and thereafter formed by a proportional scroll having a divergence angle of 11 °, the characteristic indicated by PI shown in FIG.
It is effective in the middle to high air volume region as compared with the case where only the logarithmic scroll having the divergence angle of 7.5 ° is formed, and is effective in the low wind region as compared with the case where only the proportional scroll having the divergence angle of 11 ° is formed. Thus, it is possible to obtain a stable air volume and discharge pressure as a whole.

[0029]

As described above, according to the present invention, the scroll from the base point of the scroll to the predetermined winding angle is formed by a scroll having a large rate of change, and a small change rate from the predetermined winding angle. The size of the scroll can be reduced by forming it with a scroll having an expansion ratio of. Further, with this, the discharge pressure can be increased with the same size, so that the blowing efficiency can be improved.

[Brief description of the drawings]

1 is a sectional view of a blower unit according to an embodiment of the present invention, taken along the line II of FIG. 2;

FIG. 2 is a cross-sectional view of the blower unit according to the embodiment of the present invention, taken along line II-II of FIG.

FIG. 3 shows a relationship between a winding angle of a scroll and an expansion ratio of the blower unit of the present invention.

FIG. 4 is an explanatory diagram showing a wind speed distribution of the blower unit of the present invention.

FIG. 5 is a characteristic diagram showing a relationship between an air volume and a discharge pressure in the case of logarithmic scrolling and proportional scrolling.

[Explanation of symbols]

 Reference Signs List 1 blower unit 2 case 3 motor 4 multi-blade fan 23 scroll 23a first scroll 23b second scroll 26 tongue 29 discharge port

Claims (3)

[Claims] 1. A multi-blade fan having a plurality of blades, an inlet opening at a side in the rotation axis direction of the multi-blade fan, and an air outlet formed at a predetermined position in the rotation direction of the multi-blade fan.
A blower unit comprising: a tongue formed at a base of the outlet and closest to the multi-blade fan; and a scroll formed from the tongue to the outlet along a rotation direction of the multi-blade fan; The scroll includes a first scroll formed at a first spreading ratio from the tongue portion to a predetermined winding angle position, and a first scroll smaller than the first spreading ratio from the predetermined winding angle position to the outlet. 2. A blower unit comprising a second scroll formed with an expansion ratio of 2. 2. The blower unit according to claim 1, wherein the first scroll is a logarithmic scroll that increases at a logarithmic spread angle, and the second scroll is a proportional scroll that increases at a proportional spread angle. . 3. The first scroll, wherein the first scroll is a first logarithmic scroll increasing at a first logarithmic spread angle, and the second scroll is a second logarithmic scroll.
The blower unit according to claim 1, wherein the scroll is a second logarithmic scroll that increases at a second logarithmic divergence angle smaller than the first logarithmic divergence angle.