U.S. patent application number 10/755253 was filed with the patent office on 2004-08-26 for centrifugal air blower unit having movable portion.
Invention is credited to Miyata, Manabu, Ochiai, Toshinori.
Application Number | 20040165984 10/755253 |
Document ID | / |
Family ID | 32866176 |
Filed Date | 2004-08-26 |
United States Patent
Application |
20040165984 |
Kind Code |
A1 |
Ochiai, Toshinori ; et
al. |
August 26, 2004 |
Centrifugal air blower unit having movable portion
Abstract
A centrifugal air blower unit includes a centrifugal multi-blade
fan, a scroll casing, and an introduction duct. The fan has a
rotation axis and a plurality of blades. The scroll casing provides
a first air passage. The introduction duct provides a second air
passage. The fan sucks the air from the rotation axis and blows the
air toward the outer circumference of the fan. The first and second
air passages flow the air blown from the fan. The inner wall of the
introduction duct includes a movable portion. The inner wall of the
introduction duct is smoothly jointed between the first and second
air passages even when the movable portion is displaced in
accordance with the airflow amount of the air blown from the scroll
casing.
Inventors: |
Ochiai, Toshinori;
(Obu-city, JP) ; Miyata, Manabu; (Obu-city,
JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
32866176 |
Appl. No.: |
10/755253 |
Filed: |
January 9, 2004 |
Current U.S.
Class: |
415/206 |
Current CPC
Class: |
F04D 29/422 20130101;
F01D 17/143 20130101; F04D 29/441 20130101; F01D 17/146
20130101 |
Class at
Publication: |
415/206 |
International
Class: |
F01D 001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 9, 2003 |
JP |
2003-003273 |
Claims
What is claimed is:
1. A centrifugal air blower unit for blowing an air to a heat
exchanger, the unit comprising: a centrifugal multi-blade fan
having a rotation axis with an axial direction, an outer
circumference and a plurality of blades disposed around the
rotation axis of the fan; a scroll casing for accommodating the fan
and for providing a first air passage so as to flow the air by an
airflow amount; and an introduction duct having an inner wall for
providing a second air passage, wherein the fan sucks the air from
the axial direction of the rotation axis and blows the air toward
the outer circumference of the fan, wherein the first air passage
has a scroll shape and flows the air blown from the fan, wherein
the second air passage introduces the air blown from the scroll
casing toward the heat exchanger, wherein the inner wall of the
introduction duct includes a movable portion, and wherein the inner
wall of the introduction duct is smoothly jointed between the first
and second air passages even when the movable portion is displaced
in accordance with the airflow amount of the air blown from the
scroll casing.
2. The unit according to claim 1, wherein each of the first and
second passages includes an upstream side and a downstream side,
and wherein the inner wall of the introduction duct is smoothly
jointed from the upstream side to the downstream side of the first
and second air passages.
3. The unit according to claim 1, wherein the movable portion
includes a seal for preventing an air leakage.
4. A centrifugal air blower unit for blowing an air to a heat
exchanger, the unit comprising: a centrifugal multi-blade fan
having a rotation axis with an axial direction, an outer
circumference and a plurality of blades disposed around the
rotation axis of the fan; a scroll casing with a nose for
accommodating the fan and for providing a first air passage so as
to flow the air by an airflow amount; and an introduction duct
having an inner wall for providing a second air passage, wherein
the fan sucks the air from the axial direction of the rotation axis
and blows the air toward the outer circumference of the fan,
wherein the first air passage has a scroll shape and flows the air
blown from the fan, wherein the second air passage introduces the
air blown from the scroll casing toward the heat exchanger, wherein
the inner wall of the introduction duct includes a movable portion,
which connects to the nose of the scroll casing, and wherein the
inner wall of the introduction duct is smoothly jointed between the
first and second air passages even when the movable portion of the
inner wall of the introduction duct is displaced in accordance with
the airflow amount of the air blown from the scroll casing.
5. The unit according to claim 4, wherein each of the first and
second passages includes an upstream side and a downstream side,
and wherein the inner wall of the introduction duct is smoothly
jointed from the upstream side to the downstream side of the first
and second air passages.
6. The unit according to claim 4, wherein the movable portion
includes a first movable portion and a second movable portion,
wherein the first movable portion is disposed from the nose toward
the scroll casing so that the first movable portion provides a part
of the scroll casing, and wherein the second movable portion is
disposed from the nose toward the heat exchanger so that the second
movable portion provides a part of the introduction duct.
7. The unit according to claim 4, wherein the scroll casing
includes a side wall, and wherein the first movable portion moves
along with the sidewall of the scroll casing.
8. A centrifugal air blower unit for blowing an air to a heat
exchanger, the unit comprising: a centrifugal multi-blade fan
having a rotation axis with an axial direction, an outer
circumference and a plurality of blades disposed around the
rotation axis of the fan; a scroll casing with an outer periphery
for accommodating the fan and for providing a first air passage so
as to flow the air by an airflow amount; and an introduction duct
having an inner wall for providing a second air passage, wherein
the fan sucks the air from the axial direction of the rotation axis
and blows the air toward the outer circumference of the fan,
wherein the first air passage has a scroll shape and flows the air
blown from the fan, wherein the second air passage introduces the
air blown from the scroll casing toward the heat exchanger, wherein
the inner wall of the introduction duct includes a movable portion,
which connects to the inner wall disposed at the outer periphery of
the scroll casing, and wherein the inner wall of the introduction
duct is smoothly jointed between the first and second air passages
even when the movable portion of the inner wall of the introduction
duct is displaced in accordance with the airflow amount of the air
blown from the scroll casing.
9. The unit according to claim 8, wherein each of the first and
second passages includes an upstream side and a downstream side,
and wherein the inner wall of the introduction duct is smoothly
jointed from the upstream side to the downstream side of the first
and second air passages.
10. An air conditioning apparatus for a passenger compartment of a
vehicle, the apparatus comprising: a centrifugal air blower unit
according to claim 1; a blower mode switching device for switching
a blower mode of the air to be blown into the passenger
compartment; and a controller, wherein the controller controls the
airflow amount of the air blowing from the scroll casing on the
basis of an operating condition of the blower mode switching
device.
11. An automatically controlled air conditioning apparatus for a
passenger compartment of a vehicle, the apparatus comprising: a
centrifugal air blower unit according to claim 1; and a controller
for calculating a target temperature of the air to be blown into
the compartment and for controlling at least one of a blower mode
of the air to be blown into the passenger compartment and an
airflow amount of the air blowing from the centrifugal air blower
unit on the basis of the target temperature, wherein the controller
controls the airflow of the air blowing from the scroll casing on
the basis of the target temperature.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on Japanese Patent Application No.
2003-3273 filed on Jan. 9, 2003, the disclosure of which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a centrifugal air blower
unit having a movable portion, which is suitably applied for an air
blower unit of an air conditioning apparatus.
BACKGROUND OF THE INVENTION
[0003] A conventional centrifugal air blower unit is disclosed and
specifically described in Japanese Unexamined Patent Application
Publication No. 2002-161896 and Japanese Examined Patent
Application Publication No. H07-92079.
[0004] A scroll casing of the centrifugal air blower unit provides
an air passage having a scroll shape (i.e., a convolution shape).
The air passage is disposed on an outer circumference of a
centrifugal multi-blade fan. A cross section of the air passage
becomes gradually larger, as it goes from a nose (i.e., a volute
tongue of the scroll casing) to an end of the scroll casing so that
the air in the air passage is effectively congregated, and then the
air is blown from the centrifugal multi-blade fan to the downstream
side of the fan.
[0005] Therefore, the optimum dimensions of a figure size of the
scroll casing is required to vary in relation to an amount of the
air to be blown from the scroll casing. Specifically, an increasing
rate of the cross section of the air passage (e.g., an expanding
angle of the air passage) and the cross section of the air passage
are changed in relation to the air-blow amount for optimizing
them.
[0006] Therefore, in the prior art, the air blower unit includes a
variable blade in the air passage, which has a scroll shape
provided by the scroll casing. The variable blade moves toward a
direction parallel to the rotation axis of the centrifugal
multi-blade fan in relation to the air-blow amount so that the
cross section of the air passage is changed.
[0007] Specifically, the air blower unit includes a door means 124
disposed near an air outlet of the scroll casing 172, as shown in
FIG. 7. The door means 124 rotates around a rotation axis, which is
parallel to the rotation axis of the centrifugal multi-blade fan
171. The door means 124 switches a door between opening and closing
in relation to an operation mode. Specifically, the door means 124
optimizes the dimensions of the figure size of the scroll casing
172, i.e., the door means optimizes the dimensions of the air
passage in relation to the air-blow amount.
[0008] In this case, the cross section of the air passage in the
scroll casing 172 becomes much larger, just after the air passes
through the door means 124. Therefore, a turbulence of the airflow,
i.e., a vortex of the airflow is generated at the downstream side
of the door means 124 in the airflow direction. That is because the
air, which flows along with a sidewall of the door means 124 and
the scroll casing 172 in a case where the door means 124 is opened,
breaks away from the sidewall of the scroll casing 172 in a case
where the door means 124 is closed. Thus, a noise generated by the
vortex of the airflow becomes larger, and the air-blow amount of
the air blowing from the air blower unit is decreased by a vortex
loss of the vortex of the airflow.
SUMMARY OF THE INVENTION
[0009] In view of the above problem, it is an object of the present
invention to provide a new centrifugal air blower unit.
Specifically, the centrifugal air blower unit has high air-blow
efficiency and low air-blow noise.
[0010] A centrifugal air blower unit blows an air to a heat
exchanger. The unit includes a centrifugal multi-blade fan, a
scroll casing, and an introduction duct. The centrifugal
multi-blade fan has a rotation axis with an axial direction, an
outer circumference and a plurality of blades disposed around the
rotation axis of the fan. The scroll casing accommodates the fan
and provides a first air passage so as to flow the air by an air
flow amount. The introduction duct has an inner wall and provides a
second air passage. The fan sucks the air from the axial direction
of the rotation axis and blows the air toward the outer
circumference of the fan. The first air passage has a scroll shape
and flows the air blown from the fan. The second air passage
introduces the air blown from the scroll casing toward the heat
exchanger. The inner wall of the introduction duct includes a
movable portion. The inner wall of the introduction duct is
smoothly jointed between the first and second air passages even
when the movable portion is displaced in accordance with the
airflow amount of the air blown from the scroll casing.
[0011] In the above unit, both of the first and second air passages
can be optimized in accordance with the airflow amount. Even when
the movable portion is displaced, all circumference of the inner
wall of the duct is continuously (i.e., smoothly) jointed from the
upstream side to the downstream side of the air passages.
Therefore, no vortex is generated in the duct. Thus, a noise
generated by the vortex of the airflow is reduced, and the airflow
amount of the air blowing from the airblower unit is prevented from
decreasing. Here, the decreasing of the air-blow amount is caused
by a vortex loss of the vortex of the airflow.
[0012] Thus, the centrifugal air blower unit has high air-blow
efficiency and low air-blow noise.
[0013] Further, a centrifugal air blower unit blows an air to a
heat exchanger. The unit includes a centrifugal multi-blade fan, a
scroll casing, and an introduction duct. The centrifugal
multi-blade fan has a rotation axis with an axial direction, an
outer circumference and a plurality of blades disposed around the
rotation axis of the fan. The scroll casing with a nose
accommodates the fan and provides a first air passage so as to flow
the air by an airflow amount. The introduction duct has an inner
wall and provides a second air passage. The fan sucks the air from
the axial direction of the rotation axis and blows the air toward
the outer circumference of the fan. The first air passage has a
scroll shape and flows the air blown from the fan. The second air
passage introduces the air blown from the scroll casing toward the
heat exchanger. The inner wall of the introduction duct includes a
movable portion, which connects to the nose of the scroll casing.
The inner wall of the introduction duct is smoothly jointed between
the first and second air passages even when the movable portion of
the inner wall of the introduction duct is displaced in accordance
with the airflow amount of the air blown from the scroll
casing.
[0014] In the above unit, both of the first and second air passages
can be optimized in accordance with the airflow amount. No vortex
is generated in the duct, so that the airflow amount of the air
blowing from the air blower unit is prevented from decreasing.
Thus, the centrifugal air blower unit has high air-blow efficiency
and low air-blow noise.
[0015] Further, a centrifugal air blower unit blows an air to a
heat exchanger. The unit includes a centrifugal multi-blade fan, a
scroll casing, and an introduction duct. The centrifugal
multi-blade fan has a rotation axis with an axial direction, an
outer circumference and a plurality of blades disposed around the
rotation axis of the fan. The scroll casing with an outer periphery
accommodates the fan and provides a first air passage so as to flow
the air by an airflow amount. The introduction duct has an inner
wall and provides a second air passage. The fan sucks the air from
the axial direction of the rotation axis and blows the air toward
the outer circumference of the fan. The first air passage has a
scroll shape and flows the air blown from the fan. The second air
passage introduces the air blown from the scroll casing toward the
heat exchanger. The inner wall of the introduction duct includes a
movable portion, which connects to the inner wall disposed at the
outer periphery of the scroll casing. The inner wall of the
introduction duct is smoothly jointed between the first and second
air passages even when the movable portion of the inner wall of the
introduction duct is displaced in accordance with the airflow
amount of the air blown from the scroll casing.
[0016] In the above unit, both of the first and second air passages
can be optimized in accordance with the airflow amount. No vortex
is generated in the duct, so that the airflow amount of the air
blowing from the air blower unit is prevented from decreasing.
Thus, the centrifugal air blower unit has high air-blow efficiency
and low air-blow noise.
[0017] Further, an air conditioning apparatus is suitably used for
a passenger compartment of a vehicle. The apparatus includes a
centrifugal air blower unit according to claim 1; a blower mode
switching device for switching a blower mode of the air to be blown
into the passenger compartment; and a controller. The controller
controls the airflow amount of the air blowing from the scroll
casing on the basis of an operating condition of the blower mode
switching device.
[0018] In the above apparatus, the centrifugal air blower unit has
high air-blow efficiency and low air-blow noise, so that the
apparatus is much improved.
[0019] Further, an automatically controlled air conditioning
apparatus is suitably used for a passenger compartment of a
vehicle. The apparatus includes a centrifugal air blower unit
according to claim 1; and a controller for calculating a target
temperature of the air to be blown into the compartment and for
controlling at least one of a blower mode of the air to be blown
into the passenger compartment and an airflow amount of the air
blowing from the centrifugal air blower unit on the basis of the
target temperature. The controller controls the airflow of the air
blowing from the scroll casing on the basis of the target
temperature. In the above apparatus, the centrifugal air blower
unit has high air-blow efficiency and low air-blow noise, so that
the apparatus is much improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above and other objects, features and advantages of the
present invention will become more apparent from the following
detailed description made with reference to the accompanying
drawings. In the drawings:
[0021] FIG. 1 is a schematic view showing an air conditioning
apparatus, according to a first embodiment of the present
invention;
[0022] FIG. 2 is a block diagram showing the air conditioning
apparatus according to the first embodiment;
[0023] FIG. 3 is a schematic cross sectional view showing a
centrifugal air blower unit according to the first embodiment;
[0024] FIG. 4 is a cross sectional view explaining an operation of
the air blower unit according to the first embodiment;
[0025] FIG. 5 is a cross sectional view explaining the operation of
the air blower unit according to the first embodiment;
[0026] FIG. 6 is a schematic cross sectional view showing a
centrifugal air blower unit according to a second embodiment of the
present invention; and
[0027] FIG. 7 is a schematic cross sectional view showing a
centrifugal air blower unit according to a prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] (First Embodiment)
[0029] A centrifugal air blower unit according to a first
embodiment of the present invention is suitably used for an air
conditioning apparatus 1 of a vehicle, as shown in FIG. 1.
[0030] At the upstream side of an air conditioning casing 2 in the
airflow direction of an airflow path, an inner-air inlet port 3, an
outer-air inlet port 4 and an air-switching door 5 are disposed.
The inner-air inlet port 3 sucks the inner air disposed in a
passenger compartment of the vehicle. The outer-air inlet port 4
sucks the outer air disposed outside of the compartment. The
inside/outside air-switching door 5 switches the inlet ports 3, 4.
The air-switching door 5 is controlled (i.e., opened or closed)
manually or by a servomotor or the like.
[0031] At the downstream side of the air-switching door 5, a filter
(not shown) for filtering the air dusts and a centrifugal air
blower unit 7 are disposed. The air is sucked by the air blower
unit 7 through the inlet ports 3, 4, and then blown toward air
outlets 14, 15, 17.
[0032] At the downstream side from the air blower unit 7, an
evaporator 9 is disposed. The evaporator 9 is a cooling device for
cooling the air to be blown into the passenger compartment. The air
sent by the air blower unit 7 passes entirely through the
evaporator 9. Here, the evaporator 9 is a low-pressure side heat
exchanger in a vapor compression refrigerating system. The system
cools the air by evaporating a refrigerant in the system.
[0033] At the downstream side from the evaporator 9, a heater 10
for heating the air to be blown into the passenger compartment is
disposed. The heater 10 heats the air with using a coolant of an
engine 11 (i.e., E/G) as a heat source.
[0034] A bypass passage 12 for bypassing the heater 10 is disposed
in the air conditioning casing 2. An air mix door 13 is disposed at
the upstream side from the heater 10. The air mix door 13 controls
a ratio between the air passing through the heater 10 and the air
passing through the bypass passage 12 so that the air mix door 13
controls the temperature of the air to be blown into the passenger
compartment. At the downstream side of the air conditioning casing
2, air outlets 14, 15, 17 are disposed. The air outlet 14 works as
a FACE outlet for blowing the air toward an upper side of the
passenger compartment, so that the air blows toward an upper body
of a passenger in the passenger compartment. That is called a face
mode of the air conditioning apparatus. The air outlet 15 works as
a FOOT outlet for blowing the air toward a lower side of the
passenger compartment, so that the air blows toward a lower body of
the passenger in the passenger compartment. That is called a foot
mode of the air conditioning apparatus. The air outlet 15 works as
a DEFROSTER outlet for blowing the air toward a window shield glass
16 (i.e., the inner surface of the glass 16) of the vehicle. That
is called a defroster mode of the air conditioning apparatus.
[0035] Each outlet 14, 15, 17 has a blower mode switching door 18,
19, 20, respectively. The blower mode switching door 18, 19, 20 is
disposed at the upstream side from the outlet 14, 15, 17. The
blower mode switching door 18, 19, 20 controls and switches a
blower mode among the face mode, the foot mode and the defroster
mode. The blower mode switching door 18, 19, 20 is controlled
manually or by a servomotor or the like.
[0036] Thus, the blower mode is composed of the face mode for
blowing the air from the FACE outlet 14, the foot mode for blowing
the air from the FOOT outlet 15, and the defroster mode for blowing
the air from the DEFROSTER outlet 17. The blower mode further
includes a bi-level mode for blowing the air from both of the FACE
outlet 14 and the FOOT outlet 15, and so on.
[0037] In general, when the air conditioning apparatus 1 is
operated in the FACE mode, it is required to have a large amount of
the air-blow to be blown into the compartment. Therefore, the FACE
outlet 14 is set to be parallel to the air passage of the air
conditioning casing 2 so that a pressure loss (i.e., an airflow
resistance of the air passage) in case of the FACE mode becomes
smaller than that in case of the FOOT mode, the DEFROSTER mode and
the like.
[0038] As shown in FIG. 2, several signals are inputted into an
electronic control unit (i.e., ECU). The signals are a detection
signals outputted from a plurality of air conditioning sensors 22
and a signal outputted from an operation panel 23. The detection
signals are, for example, a detection signal from an outside air
temperature sensor for detecting the temperature of the outside air
outside the passenger compartment, a detection signal from an
cooled air temperature sensor for detecting the temperature of the
air just after passing through the evaporator 9, a detection signal
from a solar radiation sensor for detecting an amount of solar
radiation entered into the passenger compartment. The signal from
the operation panel 23 disposed in the passenger compartment
corresponds to a setting temperature, which is set by the passenger
in the passenger compartment.
[0039] The ECU 21 calculates a target temperature TAO in accordance
with a predetermined program on the basis of the above signals
inputted into the ECU 21. The target temperature TAO is a target
temperature of the air to be blown into the passenger compartment.
Specifically, the target temperature TAO is calculated, and then
the ECU 21 controls the air-switching door 5, the air mix door 13,
the blower mode switching doors 18, 19, 20 and the air blower unit
7. Here, the ECU 21 controls the air blower unit 7 with an applied
voltage applied to an electric motor (not shown) of the air blower
unit 7, so that the airflow amount of the air blower unit 7 is
controlled. The electric motor rotates the centrifugal multi-blade
fan 71.
[0040] Next, the air blower unit 7 is described in detail as
follows.
[0041] As shown in FIG. 3, the air blower unit 7 includes the
centrifugal multi-blade fan 71, an electric fan motor (not shown),
a scroll casing 72, a introduction duct 73 and the like. The fan 71
includes a plurality of blades 71a, which is disposed around a
rotation axis of the centrifugal multi-blade fan 71, so that the
fan 71 sucks the air from the rotation axis, and blows the air
toward the outer periphery of the fan 71. The fan motor works as a
driving means for rotating the fan 71, and is disposed on one side
of the rotation axis of the fan 71. The scroll casing 72
accommodates the fan 71, and provides an air passage 72a having a
scroll shape (i.e., a convolution shape). The air blown from the
fan 71 flows in the air passage 72a. The air blown from the scroll
casing 72 is introduced into the evaporator 9 through the
introduction duct 73, so that the introduction duct 73 works as
another air passage.
[0042] A cross section of the air passage 72a in the scroll casing
72 becomes gradually larger, as it goes from a nose 72b (i.e., a
volute tongue of the scroll casing 72) to an end of the scroll
casing 72 so that the air in the air passage 72a is effectively
congregated (i.e., smoothly blown), and then the air is blown from
the fan 71 toward the downstream side from the fan 71. In this
embodiment, the cross section of the air passage 72a is gradually
increased along with a logarithmic spiral curve. Specifically, a
scroll angle measured from the nose 72b is along with the
logarithmic spiral curve.
[0043] The introduction duct 73 includes an inner wall, all
circumference of which is continuously (i.e., smoothly) jointed
from the upstream side to the downstream side of the air passage.
That is, the inner wall is smooth without any critical concavity or
convexity on the inner wall. The inner wall includes an inside
inner wall 73a and an outside inner wall 73b. The inside inner wall
73a is continuously (i.e., smoothly) jointed to the nose 72b, and
can be displaced to a predetermined position so that the cross
section of the air passage of the introduction duct 73 (i.e., the
cross section of the duct 73) is changed in accordance with the
airflow amount of the air blown from the scroll casing 72.
[0044] Specifically, the inside inner wall 73a moves around the
rotation axis of the fan 71, so that the air passage of the duct 73
is displaced between a maximum airflow position (shown as a solid
line in FIG. 3) and a minimum airflow position (shown as a broken
line in FIG. 3). Here, in case of the maximum airflow position, the
amount of the airflow in the duct 73 becomes maximum, i.e., the
cross section of the air passage of the duct 73 becomes large. In
case of the minimum airflow position, the amount of the airflow in
the duct 73 becomes minimum, i.e., the cross section of the air
passage of the duct 73 becomes small. Thus, the inside inner wall
73a works as a movable wall, which connects between the nose 72b of
the scroll casing 72 and a casing for accommodating the evaporator
9.
[0045] The outside inner wall 73b faces the inside inner wall 73a,
and is disposed on the inner wall of the duct 73. The outside inner
wall 73b is smoothly jointed from the inner wall of the scroll
casing 72, which is disposed on an outer periphery of the scroll
casing 72. The outside inner wall 73b is formed integrally with the
scroll casing 72 and is made of resin.
[0046] A sliding portion between the inside inner wall 73a and the
scroll casing 72 and another sliding portion between the inside
inner wall 73a and the casing of the evaporator 9 are sealed with a
packing as a sealing means for sealing the air from leakage.
Specifically, the inside inner wall 73a includes the first movable
portion and the second movable portion. The first movable portion
is disposed from the nose 72b toward the scroll casing 72 so that
the first movable portion provides a part of the scroll casing 72.
The second movable portion is disposed from the nose 72b toward the
heat exchanger 9 so that the second movable portion provides a part
of the introduction duct 73.
[0047] Next, the air blower unit 7 has characteristics described as
follows.
[0048] As shown in FIG. 4, the applied voltage applied to the fan
motor is increased so that the airflow amount of the air blowing
from the fan 71 becomes larger. In this case, the inside inner wall
73a is displaced toward a direction opposite to the outside inner
wall 73b so that the cross section of the duct 73 is increased.
[0049] As shown in FIG. 5, the applied voltage applied to the fan
motor is decreased so that the airflow amount of the air blowing
from the fan 71 becomes smaller. In this case, the inside inner
wall 73a is displaced toward the outside inner wall 73b so that the
cross section of the duct 73 is decreased.
[0050] Thus, both of the air passage in the duct 73 and the air
passage 72a in the scroll casing 72 can be optimized in accordance
with the airflow amount.
[0051] Even when the inside inner wall 73a is displaced, all
circumference of the inner wall of the duct 73 is continuously
(i.e., smoothly) jointed from the upstream side to the downstream
side of the air passage. Therefore, no vortex is generated in the
duct 73. Thus, a noise generated by the vortex of the airflow is
reduced, and the air-blow amount of the air blowing from the air
blower unit 7 is prevented from decreasing. Here, the decreasing of
the air-blow amount is caused by a vortex loss of the vortex of the
airflow.
[0052] Thus, the centrifugal air blower unit 7 has high air-blow
efficiency and low air-blow noise.
[0053] (Second Embodiment)
[0054] A centrifugal air blower unit 207 according to a second
embodiment of the present invention is shown in FIG. 6. The
centrifugal air blower unit 207 includes an outside inner wall 273b
as a movable wall. The outside inner wall 273b includes a movable
inner wall 273c disposed on the scroll casing side and another
movable inner wall 273d disposed on the evaporator side. A sliding
portion 73e between the movable inner walls 273c, 273d is sealed
with a lip seal (i.e., a lip packing) as a sealing means for
sealing the air from leakage. The lip seal is, for example, made of
fluorocarbon rubber such as elastomer rubber, so that the lip seal
is formed integrally with the movable inner walls 273c, 273d.
[0055] In FIG. 6, the maximum airflow position is shown as a solid
line, and the minimum airflow position is shown as a broken
line.
[0056] Thus, both of the air passage in the duct 73 and the air
passage 72a in the scroll casing 72 can be optimized in accordance
with the air-blow amount. Even when the outside inner wall 273b is
displaced, all circumference of the inner wall of the duct 73 is
continuously (i.e., smoothly) jointed from the upstream side to the
downstream side of the air passage. Therefore, no vortex is
generated in the duct 73. Thus, a noise generated by the vortex of
the airflow is reduced, and the air-blow amount of the air blowing
from the air blower unit is prevented from decreasing. Here, the
decreasing of the air-blow amount is caused by a vortex loss of the
vortex of the airflow.
[0057] Thus, the centrifugal air blower unit 207 has high air-blow
efficiency and low air-blow noise.
[0058] (Third Embodiment)
[0059] In the air blower units 7, 207 shown in FIGS. 3 and 6, the
movable inner walls 73a, 273c, 273d are displaced in accordance
with the applied voltage applied to the fan motor. In these cases,
when the blower mode is switched, the air-blow resistance is also
changed. Therefore, the actual air-blow amount is changed.
[0060] In view of the above point, in a centrifugal air blower unit
307 according to a third embodiment of the present invention, the
movable inner walls 73a, 273c, 273d are displaced in accordance
with the blower mode (i.e., the operating condition of each blower
mode switching door 18-20).
[0061] Specifically, in case of the face mode, the air-blow
resistance becomes small so that the air-blow amount is increased.
Therefore, the movable inner wall 73a, 273c, 273d is displaced to
the maximum airflow position. In case of the foot mode or the
defroster mode, the air-blow resistance becomes large so that the
air-blow amount is decreased. Therefore, the movable inner wall
73a, 273c, 273d is displaced to the minimum airflow position. Here,
in case of the bi-level mode, the air-blow resistance is moderate,
so that the movable inner wall 73a, 273c, 273d is displaced to a
middle position between the maximum airflow position and the
minimum airflow position.
[0062] Thus, both of the air passage in the duct 73 and the air
passage 72a in the scroll casing 72 can be optimized in accordance
with the air-blow amount. Even when the movable inner wall 73a,
273c, 273d is displaced, all circumference of the inner wall of the
duct 73 is continuously (i.e., smoothly) jointed from the upstream
side to the downstream side of the air passage. Therefore, no
vortex is generated in the duct 73. Thus, a noise generated by the
vortex of the airflow is reduced, and the air-blow amount of the
air blowing from the air blower unit 307 is prevented from
decreasing.
[0063] Thus, the centrifugal air blower unit 307 has high air-blow
efficiency and low air-blow noise.
[0064] (Fourth Embodiment)
[0065] In case of an automatically controlled air conditioning
apparatus, the ECU 21 controls the applied voltage applied to the
fan motor and the blower mode on the basis of the target
temperature TAO. Accordingly, in a centrifugal air blower unit 407
according to a fourth embodiment of the present invention, the
movable inner walls 73a, 273c, 273d are displaced in accordance
with the target temperature TAO.
[0066] Specifically, when the target temperature TAO is set to be
low, the air conditioning apparatus 1 operates in a cooling
operation mode so that the blower mode becomes the face mode. When
the target temperature TAO is set to be high, the air conditioning
apparatus 1 operates in a heating operation mode so that the blower
mode becomes the foot mode. Therefore, when the target temperature
TAO is set to be lower than the first predetermined temperature,
the movable inner wall 73a, 273c, 273d is displaced to the maximum
airflow position. When the target temperature TAO is set to be
higher than the second predetermined temperature, the movable inner
wall 73a, 273c, 273d is displaced to the minimum airflow position.
Here, the second predetermined temperature is higher than the first
predetermined temperature. When the target temperature TAO is set
to be in a range between the first predetermined temperature and
the second predetermined temperature, the movable inner wall 73a,
273c, 273d is displaced to the middle position between the maximum
airflow position and the minimum airflow position in accordance
with the target temperature TAO.
[0067] Thus, both of the air passage in the duct 73 and the air
passage 72a in the scroll casing 72 can be optimized in accordance
with the air-blow amount. Even when the movable inner wall 73a,
273c, 273d is displaced, all circumference of the inner wall of the
duct 73 is continuously (i.e., smoothly) jointed from the upstream
side to the downstream side of the air passage. Therefore, no
vortex is generated in the duct 73. Thus, a noise generated by the
vortex of the airflow is reduced, and the air-blow amount of the
air blowing from the air blower unit 407 is prevented from
decreasing.
[0068] Thus, the centrifugal air blower unit 407 has high air-blow
efficiency and low air-blow noise.
[0069] (Modifications)
[0070] Although the air blower unit 7, 207, 307, 407 is applied to
the air conditioning apparatus for the vehicle, the air blower unit
7, 207, 307, 407 can be used for another air conditioning apparatus
for a ship, an airplane, and the like.
[0071] Although the movable inner walls 73a, 273c, 273d are
displaced with using a gear system or a link system, the movable
inner walls 73a, 273c, 273d can be displaced with using another
driving means.
[0072] Although each movable inner wall 73a, 273c, 273d has a
certain shape shown in FIGS. 3 and 6, the movable inner walls 73a,
273c, 273d can have another shape.
[0073] Further, the movable inner walls 73a, 273c, 273d can be
displaced in accordance with an airflow pressure detected by a
pressure sensor. The airflow pressure is provided by the air-blow
blown from the air blower unit 7, 207, 307, 407.
[0074] In the air conditioning apparatus 1 for the passenger
compartment of the vehicle, the apparatus can includes a detector
for detecting the airflow amount of the air blowing from the scroll
casing 72 on the basis of an operating condition of the blower mode
switching doors 18-20. In this case, the movable inner walls 73a,
273c, 273d is displaced in accordance with the airflow amount
detected by the detector.
[0075] In the automatically controlled air conditioning apparatus,
the apparatus can includes a controller and a detector. The
controller controls at least one of the blower mode of the air to
be blown into the passenger compartment and the airflow amount of
the air blowing from the centrifugal air blower unit 7, 207, 307,
407 on the basis of the target temperature TAO of the air to be
blown into the compartment. The detector detects the airflow of the
air blowing from the scroll casing 72 on the basis of the target
temperature TAO. In this case, the movable inner walls 73a, 273c,
273d is displaced in accordance with the target temperature
TAO.
[0076] Such changes and modifications are to be understood as being
within the scope of the present invention as defined by the
appended claims.
* * * * *