JP2002161896A - Centrifugal fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal fan capable of realizing a small size, enhancing a fan efficiency of the centrifugal fan corresponding to a variation of an air amount and reducing a blast noise. SOLUTION: A scroll chamber 4a is formed such that it is gradually enlarged toward a fan discharge port 4c of a casing 4 in radial and axial directions to realize a small size. A variable blade 5 for varying an axial enlargement of the scroll chamber 4a corresponding to an air amount of the multiblade fan 2 is provided in the scroll chamber 4a. An enhancement of the fan efficiency and a reduction of the blase noise are compatible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal blower mainly used for an air conditioner for an automobile.

[0002]

2. Description of the Related Art As a blower used in a conventional air conditioner, as described in Japanese Patent Application Laid-Open No. 2000-110791, the cross sectional area is enlarged by expanding a scroll chamber toward a discharge port in a radial direction. Known centrifugal blowers are known.

[0003]

However, in the general centrifugal blower as described above, the cross-sectional area is enlarged by expanding the scroll chamber in the radial direction toward the discharge port. The size of the centrifugal blower and the air conditioner as a whole become large, which is disadvantageous in terms of vehicle mountability.

On the other hand, in an air conditioner, the air volume is controlled according to the conditions such as cooling and heating, and a set temperature. However, the scroll shape and size with good fan efficiency differ depending on the air volume. That is, for example, when the scroll chamber is designed to have the highest fan efficiency when the air volume is small, the fan efficiency becomes poor when the air volume is large, and a problem arises in that the blowing noise increases.

Accordingly, the present invention provides a centrifugal blower capable of reducing the size of the centrifugal blower, improving the fan efficiency of the centrifugal blower in accordance with a change in air volume, and reducing the blowing noise. It is an object.

[0006]

According to the present invention, a multi-blade fan, a fan motor to which the multi-blade fan is attached, and a multi-blade fan with the multi-blade fan housed therein. In a structure provided with a casing having a spiral scroll chamber formed on the outer periphery, the casing is located on the opposite side of the intake side case plate with the air intake port interposed therebetween and the multi-blade fan. A motor-side case plate in which a motor main body of the fan motor is assembled, wherein the scroll chamber is formed so as to gradually expand in a radial direction and an axial direction toward a blower discharge port of a casing, and is provided in the scroll chamber. And a variable means for changing the axial expansion of the scroll chamber in accordance with the amount of air sucked or discharged by the multi-blade fan.

[0007] According to the second aspect of the present invention, the first aspect is provided.
Wherein the variable means is provided from substantially the center of the scroll chamber to the air discharge port.

According to a third aspect of the present invention, the variable means according to the first or second aspect is provided on a motor-side case plate to which a fan motor is attached.

According to a fourth aspect of the present invention, the variable means according to the third aspect is provided on a suction side case plate having an air suction port.

[0010]

According to the first aspect of the present invention, the scroll chamber is formed so as to gradually expand radially and axially toward the air outlet of the casing.
The radial expansion of the scroll chamber can be reduced, and even if the casing is made smaller by reducing the radial size of the casing, the scroll on the radial plane that spreads radially from the axis can be achieved. The cross-sectional area of the chamber can be made approximately the same as before.

Further, since the scroll chamber is provided with a variable means for changing the axial expansion of the scroll chamber in accordance with the air volume sucked or discharged by the multi-blade fan, the air volume of the centrifugal blower changes. However, the expansion in the axial direction can be varied by the variable means, so that both improvement in fan efficiency and reduction in blowing noise can be achieved.

Further, since the variable means is configured to be variable in the axial direction, the air flow generated from the centrifugal blower can maintain the flow based on the free vortex motion due to the scroll shape.

According to the second aspect of the present invention, in addition to the effect of the first aspect, since the variable means is provided from substantially the center of the scroll chamber to the air discharge port, the centrifugal centrifuge has a simple structure. The fan efficiency of the blower can be adapted according to the air volume.

That is, even if the expansion angle of the scroll chamber is constant, the variable means is provided in the vicinity of the blower discharge port where the enlarged area per unit becomes larger, so that the variable means is not provided throughout the scroll chamber. However, required performance can be obtained.

According to the invention described in claim 3, according to claim 1 of the present invention,
Alternatively, in addition to the effect of claim 2, since the variable means is provided on the motor side case plate to which the fan motor is attached, the motor side case having a relatively larger air volume than the suction side case plate side in the scroll chamber. By providing the variable means on the plate side, even if only one of the variable means is arranged, the fan efficiency of the centrifugal blower can be sufficiently adapted according to the air volume.

According to the invention set forth in claim 4, according to claim 3,
In addition to the above effects, since the variable means is provided on the suction side case plate having the air suction port, by providing the variable means also on the suction side case plate in addition to the motor side case plate, the centrifugal type The fan efficiency of the centrifugal blower can be adjusted according to the air flow while maintaining the flow of the air generated from the blower closer to the ideal.

[0017]

FIG. 1 is a perspective view showing a first embodiment which is an example of an embodiment of the present invention. FIG. 2 is a cross-sectional equivalent view in which a motor corresponding to the AA arrow of FIG. 1 is assembled, and FIG. 3 is a B arrow view of the FIG. The centrifugal blower 1 shown in FIGS. 1 to 3 is used for an air conditioner for an automobile, and includes a large number of blades 2a.
And a fan motor 3 having the multi-blade fan 2 attached to the tip of a motor shaft 3a.
And a casing 4 in which the motor main body 3b of the fan motor 3 is assembled.

The multi-blade fan 2 includes a conical conical plate 2b attached to the motor shaft 3a and covering the motor main body 3b. The fan motor 3 includes a protection case 3c for protecting a rotor and a stator in the motor body 3b, and the protection case 3c covers the entire motor body 3b.

A spiral scroll chamber 4a is formed in the casing 4 around the outer periphery of the multi-blade fan 2, and the casing 4 has an air inlet 4 for sucking air into the casing.
b, and a blower discharge port 4c that discharges blown air from the scroll chamber 4a to the outside of the casing 4. The casing 4 includes an intake-side case plate 4d having an air intake port 4b and an intake-side case plate 4d with the multi-blade fan 2 interposed therebetween.
And a peripheral wall plate forming an outer peripheral wall of the scroll chamber 4a by connecting the motor side case plate 4e to which the motor main body 3b is attached and the suction side case plate 4d and the motor side case plate 4e. 4f.

The scroll chamber 4a extends radially and axially from the tongue 4h (see FIGS. 1 and 3) of the casing 4 forming the narrowest portion of the scroll chamber 4a to the blow outlet 4c. The maximum length (height) L1 of the scroll chamber 4a in the axial direction of the motor shaft 3a is longer than the length L2 of the multi-blade fan 2 in the axial direction of the motor shaft 3a. ing.

More specifically, in the centrifugal blower 1, the scroll chamber 4a is connected to the air outlet 4c from the tongue 4h of the casing 4.
Up to a constant divergence angle (for example, approximately 6 degrees) in both the up and down directions along the axial direction of the motor shaft 3a.
Therefore, the volume of the scroll chamber 4a is increased in the axial direction of the motor shaft 3a as compared with the conventional product, and the angle of expansion in the radial direction can be set smaller by a volume equivalent to the increased volume. . For example, in the centrifugal blower 1, the casing 4 has a scroll chamber 4a whose radial expansion angle is set to approximately 3.3 degrees.

A variable blade 5 is provided in the scroll chamber 4a as variable means for changing the axial expansion of the scroll chamber 4a in accordance with the amount of air sucked or discharged by the multi-blade fan 2.

In particular, in this embodiment, as shown in FIGS. 1 and 3, the variable wings 5 extend from a radially central portion of a scroll chamber 4a formed in a spiral shape to a blowing discharge port 4c. It is set on the motor side case plate 4e.

More specifically, the variable wing 5 is provided with the scroll chamber 4.
a variable wing body 5a facing the motor-side case plate 4e constituting the wall portion a of FIG.
b, 5b.

Then, these flange portions 5b, 5b are brought into contact with the inside of the peripheral wall plate 4f and the inner wall 4i of the scroll chamber 4a.
At the same time, the end near the center of the scroll chamber 4a is rotatably connected to a connection portion 6 provided inside the scroll chamber 4a of the motor-side case plate 4e using a connection pin 6a or the like. Move (rotate) in the axial direction with the connection part 6 as a fulcrum
The scroll chamber 4 is provided in a possible flap shape, and is controlled according to the air volume of the centrifugal blower 1 controlled by an air conditioner (not shown).
The expansion in the axial direction can be changed from the substantially central portion of a to the blowing outlet 4c.

The variable wing 5 is formed by a link member (not shown) connected to a connecting portion 7 protruding from the motor-side case plate 4e through a hole, and this link member is controlled by the air conditioner by another control. It is driven in conjunction with the like.

In this embodiment, the air conditioner is driven in conjunction with a mode link (a link member for selecting an air outlet of the air conditioner).

Considering and comparing the air volume sent from the centrifugal blower 1 in the case of cooling and in the case of heating,
Due to its structure, the amount of air blown from the centrifugal blower 1 is reduced during cooling when almost all of the air is discharged by bypassing the heat exchanger for heating and during heating when most of the air is discharged via the heat exchanger for heating. It is well known that the air volume is larger during heating than during heating. On the other hand, the air conditioner selects the vent (VENT) located at the front of the upper part of the instrument panel during cooling, and selects the vent (FOOT) at the lower part of the instrument panel during heating. The outlet is also opened and closed according to cooling and heating.

That is, the mode link and the variable wing 5
And the variable blades 5 can be driven in accordance with the air volume of the centrifugal blower 1, so that the desired performance of the centrifugal blower 1 (improvement of fan efficiency and reduction of noise) can be obtained. It is.

Also, in a defroster (DEF) mode for removing fogging of windows in a vehicle other than during cooling and heating, the air volume of the centrifugal blower 1 can be relatively small. The blades 5 are driven to suppress the expansion of the scroll chamber 4a.

FIG. 4 is a graph showing an example of the air blowing performance of those shown in FIGS. In FIG. 4, the vertical axis indicates the discharge pressure at a point separated by a predetermined distance from the air discharge port 4c in the straight pipe duct connected to the air discharge port 4c of the casing 4, and the efficiency thereof, and the horizontal axis indicates the air flow. Discharge port 4c
The figure shows the discharge air volume per minute discharged from.

The broken line X indicates the air blowing performance of the centrifugal blower 1 of the present invention, the broken line Y is a centrifugal blower having the same structure as that of the centrifugal blower 1 not having the variable wings 5, and the broken line Z is the same as the conventional product. It shows the blowing performance of a centrifugal blower having a structure in which the scroll chamber expands only in the radial direction (the maximum diameter of the scroll chamber is the same as that of the other comparative objects).

As shown in FIG. 4, in the centrifugal blower of the conventional structure which expands only in the radial direction, the discharge pressure is high and the efficiency is high when the air volume is small as in heating (FOTT / DEF).
When a large air volume is required, such as during cooling (VENT),
The discharge pressure drops and the efficiency drops. On the other hand, in the case where the scroll chamber is expanded in the radial direction and the axial direction, when a large air volume is required as in the case of cooling (VENT), the discharge pressure is high and the efficiency is high, but in the case of heating (FOTT / In the case of a small air volume such as DEF), the discharge pressure is low and the efficiency is reduced.

On the other hand, it can be seen that the centrifugal blower 1 of the present invention achieves both high discharge pressure and high efficiency from a small air volume to a large air volume.

Furthermore, by forming the 5b portion of the variable wing 5 from an elastic material so as to be able to adhere to the scroll wall surface, a gap with the scroll wall surface can be prevented, so that desired performance can be obtained more efficiently.

In this embodiment, as shown in FIG. 2, the air flowing through the scroll chamber 4a is provided between the multi-blade fan 2 and the suction-side case plate 4d in the suction-side clearance G1. From the scroll chamber 4a through the air suction port 4
b, a first backflow suppressing means 10 for suppressing backflow to b.
The blowing efficiency of the centrifugal blower 1 is increased, and the vibration of the multi-blade fan 2 due to the backflow is suppressed to reduce the noise level.

The first backflow suppressing means 10 includes a fan first rib 11 continuously projecting from the multiblade fan 2 to the suction gap G1 over the entire circumferential direction of the multiblade fan 2, and a suction side case plate. The case first rib 12 is provided so as to protrude from the plate 4 d to the suction side gap G <b> 1 and continuously approaches the fan first rib 11 at a small interval over the entire circumferential direction of the multi-blade fan 2. ing.

The fan first rib 11 is provided on the upper outer periphery which is outside the fan diameter D of the multi-blade fan 2, and the case first rib 12 is provided on the air inlet 4 of the suction side case plate 4d.
b Provided on the periphery. The case first rib 12 has an inverted U-shaped cross-sectional shape that covers the fan first rib 11, and a pair of rib walls opposing each other with the fan first rib 11 interposed therebetween are formed at a slight interval. , And the inside portion forms a bell mouth portion 4g of the air suction port 4b.

The scroll chamber 4a is provided in the motor-side gap G2 between the multi-blade fan 2 and the motor-side case plate 4e.
Backflow suppression means 20 for suppressing the backflow of the air flowing through the backflow from the downstream side to the upstream side of the scroll chamber 4a via the motor-side gap G2 is provided to improve the airflow efficiency and to cause vibration of the multi-blade fan 2 due to the backflow. And reduce the noise level.

The second backflow suppressing means 20 includes a fan second rib 21 continuously projecting from the multi-blade fan 2 to the motor-side gap G2 over the entire circumferential direction of the multi-blade fan 2, and a motor-side case plate. The case second rib 22 is provided so as to protrude from the plate 4 e to the motor-side gap G <b> 2 and continuously approaches the fan second rib 21 at a small interval continuously over the entire circumferential direction of the multi-blade fan 2.
And is formed from

The fan second rib 21 is a multi-blade fan 2
The case second rib 22 is provided on the lower surface 2c on the lower end side of the motor shaft 3a of the conical plate 2b, and the motor-side case plate 4 facing the lower surface 2c of the conical plate 2b.
e is provided on the plate surface.

The distal end of the motor body 3b on the distal end side of the motor shaft 3a is exposed in a space S surrounded by the motor-side case plate 4e and the conical plate 2b of the multi-blade fan 2. The motor first communication hole 3 for connecting the inside of the motor body 3b and the space S to the protection case 3c.
d (communication hole) is provided to cool the motor body 3b.

According to the structure of the above embodiment, the scroll chamber 4a is formed so as to gradually expand radially and axially toward the air discharge port 4c of the casing 4. Of the casing 4 can be reduced in the radial direction, and even if the casing 4 is reduced in size in the radial direction by reducing the size of the casing 4 as compared with the conventional case, the scroll in the radial plane spreading radially from the axis can be achieved. Room 4a
Can be made approximately the same as the conventional one.

Further, in the scroll chamber 4a, there are provided variable blades 5 as variable means for changing the axial expansion of the scroll chamber 4a in accordance with the amount of air sucked or discharged by the multi-blade fan 2. Even when the amount of air sent from the centrifugal blower 1 changes, the expansion in the axial direction can be changed by the variable blades 5 so that both improvement in fan efficiency and reduction in blowing noise can be achieved.

Furthermore, since the variable blades 5 are made to be variable in the axial direction, the air flow generated from the centrifugal blower 1 can maintain the flow based on the free vortex motion due to the scroll shape.

In addition, according to the structure of this embodiment, in addition to the above, the variable wings 5 are provided from substantially the center of the scroll chamber 4a to the ventilation outlet 4c. The fan efficiency of the blower 1 can be adapted according to the air volume.

That is, even if the expansion angle of the scroll chamber 4a is constant, the variable wings 5 are provided in the vicinity of the blower discharge port 4c where the expansion area per unit becomes larger.
The required performance can be obtained without providing the variable wings 5 over the entire scroll chamber 4a.

Further, the variable wing 5 includes a fan motor 3
Are provided on the motor side case plate 4e to which the suction side case plate side 4e is attached in the scroll chamber 4a.
motor side case plate side 4e having a relatively large air volume than d
By providing the variable blades 5 in the above, even if the variable blades 5 are arranged only on one side, the fan efficiency of the centrifugal blower 1 can be adequately adjusted according to the air volume.

FIG. 5 shows a second embodiment of the present invention.
It is a considerable perspective view. In the following, the same components as those in the above-described first embodiment will be denoted by the same reference numerals, and redundant description will be omitted.

In the first embodiment, as shown in FIG. 2, the variable wings 5 as the variable means are provided only on the motor-side case plate 4e to which the fan motor 3 is mounted.

On the other hand, in the second embodiment, the variable wings 5 are also provided on the suction side case plate 4d having the air suction port 4b.

More specifically, similarly to the first embodiment, the variable wing 5 (5B) includes a variable wing main body 5c opposed to the suction side case plate 4d constituting the wall of the scroll chamber 4a, and both side portions thereof. And flange portions 5d, 5d extending in the axial direction from the connection portion 6 toward the air discharge port 4c.

Then, these flange portions 5d, 5d are brought into contact with the inside of the peripheral wall plate 4f and the inner wall 4i of the scroll chamber 4a.
At the same time, the end near the center of the scroll chamber 4a is rotatably connected to a connection portion 6 (6B) provided inside the scroll chamber 4a of the suction side case plate 4d using a connection pin 6b or the like. The connecting portion 6 (6B) is provided as a fulcrum in the form of a flap that can be moved (rotated) in the axial direction, and according to the air volume of the centrifugal blower 1 controlled by an air conditioner (not shown).
The axial expansion can be varied from a substantially central portion of the scroll chamber 4a to the air discharge port 4c.

The variable wing 5 (5B) is provided on the variable wing main body 5c, and extends from the suction side case plate 4d through the hole 8 (8B).
This is performed by a link member (not shown) connected to the connecting portion 7 (7B) protruding through B).

It is needless to say that the variable wing 5B provided on the suction side case plate 4d is operated in conjunction with the variable wing 5A provided on the motor side case plate 4e.
The variable amounts do not necessarily have to be the same, and each variable amount may be changed depending on the amount of air flowing through the scroll chamber 4a.

Thus, in the second embodiment, in addition to the effects of the first embodiment, the variable wing 5 (5B) as the variable means is provided.
Is provided on the suction side case plate 4d having the air suction port 4b in addition to the motor side case plate 4e, so that the air flow generated from the centrifugal The fan efficiency of the blower 1 can be adjusted according to the air volume.

FIG. 6 shows a third embodiment of the present invention.
It is a considerable side view. In the following, the same components as those in the above-described first embodiment and the second embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

In the first and second embodiments described above, the variable wings 5 are provided from substantially the center of the scroll chamber 4a to the air discharge port 4c.

On the other hand, in the third embodiment, the variable blades 5 are provided only in the substantially straight portion of the scroll chamber 4a near the air discharge port 4c.

That is, as compared with the above-described first and second embodiments in which the variable wing 5 is located at the curvature portion of the scroll chamber 4a, the setting of the power point for driving the variable wing 5 is easier, so that it is simpler. With a simple structure, the fan efficiency of the centrifugal blower 1 can be adjusted according to the air volume.

In the first to third embodiments described above, the variable wing 5 as the variable means is linked to the mode link of the air conditioner (the link member for selecting the air outlet of the air conditioner). Although the case of driving is shown as an example, the present invention is not limited to this. Needless to say, the variable blades 5 are driven in accordance with the air volume sent from the centrifugal blower 1, for example, when the air volume is manually operated. No.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional equivalent view taken along the line AA of FIG.

FIG. 3 is a view on arrow B of the one shown in FIG. 1;

FIG. 4 is a graph showing the air blowing performance of the one shown in FIG.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

FIG. 6 is a sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Far-sighted blower 2 Multi-blade fan 3 Fan motor 4 Casing 4a Scroll chamber 4b Air suction port 4c Ventilation discharge port 4d Suction side case plate 4e Motor side case plate 5 (variable blade) variable means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidenobu Arakawa 5-24-15 Minamidai, Nakano-ku, Tokyo Calso Nick Kansei Corporation (72) Inventor Fumio Henmi 5-24-15 Minamidai, Nakano-ku, Tokyo Calso Nick Kansei Corporation F term (reference) 3H034 AA02 AA18 BB02 BB06 BB19 BB20 CC03 DD12 DD26 EE06 EE12 EE18 3H035 DD04 DD05

Claims (4)

[Claims] 1. A multi-blade fan (2), a fan motor (3) to which the multi-blade fan (2) is attached, and a multi-blade fan (2) having a multi-blade fan (2) housed therein. In a structure provided with a casing (4) having a spiral scroll chamber (4a) formed on the outer periphery, the casing (4) includes a suction-side case plate (4d) having an air suction port (4b), A motor-side case plate (4e) located opposite to the suction-side case plate (4d) across the wing fan (2) and having a motor body (3b) of a fan motor (3) assembled thereto; (4a) is formed so as to gradually expand radially and axially toward the air discharge opening (4c) of the casing (4), and the multi-blade fan (2) is provided in the scroll chamber (4a). ) Depending on the air volume to be sucked or discharged. A variable means (5) for varying the axial expansion of the scroll chamber (4a). 2. The centrifugal blower according to claim 1, wherein the variable means (5) is provided from a substantially central portion of the scroll chamber (4a) to a blow discharge port (4c). 3. The centrifugal blower according to claim 1, wherein the variable means (5) is provided on a motor-side case plate (4e) to which a fan motor (3) is attached. The variable means (5) is connected to an air inlet (4).
4. The centrifugal blower according to claim 3, wherein the blower is provided on a suction side case plate (4d) having b).