U.S. patent application number 12/500819 was filed with the patent office on 2010-01-14 for inside air/outside air switching device.
This patent application is currently assigned to Toyota Jidosha Kabushiki Kaisha. Invention is credited to Donald Federico, Yoshiaki Kawato.
Application Number | 20100009620 12/500819 |
Document ID | / |
Family ID | 41505570 |
Filed Date | 2010-01-14 |
United States Patent
Application |
20100009620 |
Kind Code |
A1 |
Kawato; Yoshiaki ; et
al. |
January 14, 2010 |
INSIDE AIR/OUTSIDE AIR SWITCHING DEVICE
Abstract
An inside air/outside air switching device that includes: an
inside air/outside air switching case that has an outside air inlet
which opens into an engine room, a first inside air inlet and a
second inside air inlet which open into a vehicle compartment; an
inside air/outside air switching door that is provided in the
inside air/outside air switching case, and that switches an open
inlet between the first inside air inlet and the outside air inlet;
an inside air introduction support door that opens and closes the
second inside air inlet; and a noise insulation member that is
provided in such a manner that an operation of the inside air
introduction support door is not interfered with, and that blocks
out noise which is generated in the engine room and which proceeds
from the outside air inlet toward the second inside air inlet when
the outside air inlet is open.
Inventors: |
Kawato; Yoshiaki; (Anjo-shi,
JP) ; Federico; Donald; (Grass Lake, MI) |
Correspondence
Address: |
GIFFORD, KRASS, SPRINKLE,ANDERSON & CITKOWSKI, P.C
PO BOX 7021
TROY
MI
48007-7021
US
|
Assignee: |
Toyota Jidosha Kabushiki
Kaisha
Toyota-Shi
JP
|
Family ID: |
41505570 |
Appl. No.: |
12/500819 |
Filed: |
July 10, 2009 |
Current U.S.
Class: |
454/241 |
Current CPC
Class: |
B60H 2001/006 20130101;
B60H 1/00849 20130101; B60H 1/00685 20130101 |
Class at
Publication: |
454/241 |
International
Class: |
F24F 7/00 20060101
F24F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2008 |
JP |
JP2008-180517 |
Claims
1. An inside air/outside air switching device, comprising: an
inside air/outside air switching case that has an outside air inlet
which opens into an engine room, a first inside air inlet which
opens into a vehicle compartment, and a second inside air inlet
which opens into the vehicle compartment and which is formed in a
side wall of the inside air/outside air switching case; an inside
air/outside air switching door that is provided in the inside
air/outside air switching case, and that switches an open inlet
between the first inside air inlet and the outside air inlet; an
inside air introduction support door that opens and closes the
second inside air inlet; and a noise insulation member that is
provided in such a manner that the noise insulation member does not
interfere with an operation of the inside air introduction support
door, and that blocks out noise which is generated in the engine
room and which proceeds from the outside air inlet toward the
second inside air inlet when the outside air inlet is open.
2. The inside air/outside air switching device according to claim
1, further comprising an air blasting unit that is provided at a
position which is downstream of the inside air introduction support
door in a direction of air flow, and that takes in air introduced
into the inside air/outside air switching case through the inlets,
wherein: the inside air introduction support door is provided at a
position that is downstream of the inside air/outside air switching
door in the direction of air flow and that is on an inner side of
the second inside air inlet, moves inward from an inner wall face
of the inside air/outside air switching case when the inside air
introduction support door opens the second inside air inlet, and
opens and closes the second inside air inlet based on a change in a
pressure in the inside air/outside air switching case when the
outside air inlet is open; and the noise insulation member is
provided at a position outside but near an operation range of the
inside air introduction support door.
3. The inside air/outside air switching device according to claim
2, wherein: the pressure in the inside air/outside air switching
case when the outside air inlet is open is determined based on a
pressure of outside air that is introduced into the inside
air/outside air switching case through the outside air inlet and an
intake negative pressure that is generated when the air blasting
unit is driven; when the pressure in the inside air/outside air
switching case is lower than a pressure of inside air, the inside
air introduction support door is drawn inward from the inner wall
face to open the second inside air inlet; and when the pressure in
the inside air/outside air switching case is higher than the
pressure of the inside air, the inside air introduction support
door is pushed against the inner wall face of the inside
air/outside air switching case to close the second inside air
inlet.
4. The inside air/outside air switching device according to claim
2, wherein: the noise insulation member is provided in such a
manner that the noise insulation member covers the inside air
introduction support door; a space, through which the air that is
introduced into the inside air/outside air switching case through
the second inside air inlet flows, is left between a
downstream-side end of the noise insulation member and an upper
plate of the air blasting unit; and an end of the noise insulation
member, which is on an opposite side of the downstream-side end,
contacts the inner wall face of the inside air/outside air
switching case.
5. The inside air/outside air switching device according to claim
4, wherein: the noise insulation member is formed of two side
portions, and has a substantially L-shaped cross section; and an
inside face of an end of one of the side portions, which is the end
on the opposite side of the downstream-side end of the noise
insulation member, contacts an upper end of the inside air
introduction support door.
6. The inside air/outside air switching device according to claim
5, wherein: side plates are provided at respective longitudinal
ends of the noise insulation member; and each of the side plates
connects one of the side portions to the other side portion.
7. The inside air/outside air switching device according to claim
2, further comprising an air filter that is provided between the
inside air introduction support door and the air blasting unit, and
that filters the air introduced into the inside air/outside air
switching case through the inlets, wherein: the noise insulation
member is provided in such a manner that the noise insulation
member covers the inside air introduction support door; a small
space is left between a downstream-side end of the noise insulation
member and the air filter; an end of the noise insulation member,
which is on an opposite side of the downstream-side end, contacts
the inner wall face of the inside air/outside air switching case;
and a small space is left between each of both longitudinal ends of
the noise insulation member and the inner wall face of the inside
air/outside air switching case.
8. The inside air/outside air switching device according to claim
7, wherein: the noise insulation member is formed of two side
portions, and has a substantially L-shaped cross section; and an
inside face of an end of one of the side portions, which is the end
on the opposite side of the downstream-side end of the noise
insulation member, contacts an upper end of the inside air
introduction support door.
9. The inside air/outside air switching device according to claim
8, wherein: side plates are formed at respective longitudinal ends
of the noise insulation member; and each of the side plates
connects one of the side portions to the other side portion.
10. The inside air/outside air switching device according to claim
2, further comprising an air volume adjustment plate that is
provided at a position which is downstream of the inside air
introduction support door in the direction of air flow, and that
has a draft resistance which is substantially equal to a draft
resistance of an air filter that filters the air introduced into
the inside air/outside air switching case through the inlets,
wherein: the noise insulation member is provided in such a manner
that the noise insulation member covers the inside air introduction
support door; a small space is left between a downstream-side end
of the noise insulation member and the air volume adjustment plate;
an end of the noise insulation member, which is on an opposite side
of the downstream-side end, contacts the inner wall face of the
inside air/outside air switching case; and a small space is left
between each of both longitudinal ends of the noise insulation
member and the inner wall face of the inside air/outside air
switching case.
11. The inside air/outside air switching device according to claim
10, wherein: the noise insulation member is formed of two side
portions, and has a substantially L-shaped cross section; and an
inside face of an end of one of the side portions, which is the end
on the opposite side of the downstream-side end of the noise
insulation member, contacts an upper end of the inside air
introduction support door.
12. The inside-air/outside air switching device according to claim
11, wherein: side plates are formed at respective longitudinal ends
of the noise insulation member; and each of the side plates
connects one of the side portions to the other side portion.
13. The inside air/outside air switching device according to claim
1, further comprising: a servo motor that opens and closes the
inside air introduction support door.
Description
INCORPORATION BY REFERENCE
[0001] The disclosure of Japanese Patent Application No.
2008-180517 filed on Jul. 10, 2008 including the specification,
drawings and abstract is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to an inside air/outside air
switching device that has a first inside air inlet and a second
inside air inlet which open into a vehicle compartment, and an
outside air inlet which opens into an engine room, and more
specifically to a technology for minimizing noise that leaks from
the engine room into the vehicle compartment through the second
inside air inlet.
[0004] 2. Description of the Related Art
[0005] An inside air/outside air switching device of the
above-mentioned type is described in, for example, Japanese Patent
Application Publication No. 2002-137621 (JP-A-2002-137621). In the
inside air/outside air switching device, a second inside air inlet
is formed at a position between an inside air/outside air switching
door, which switches an open inlet between a first inside air inlet
and an outside air inlet, and an air filter, and an inside air
introduction support door that opens and closes the second inside
air inlet is provided.
[0006] The inside air introduction support door opens the second
inside air inlet when the inside air/outside air switching device
is in the outside air introduction mode in which the outside air is
drawn into the inside air/outside air switching device through the
outside air inlet. Thus, the outside air is introduced into the
inside air/outside air switching device through the outside air
inlet and part of the inside air is introduced into the inside
air/outside air switching device through the second inside air
inlet.
[0007] When the inside air/outside air switching device according
to JP-A-2002-137621 is in the outside air introduction mode in
which the outside air inlet is open, the second inside air inlet is
also open. Therefore, engine noise may enter the inside air/outside
air switching device through the outside air inlet and then leak
into a vehicle compartment through the second inside air inlet.
SUMMARY OF THE INVENTION
[0008] The invention provides an inside air/outside air switching
device that has a first inside air inlet, a second inside air
inlet, and an outside air inlet, and that is structured in such a
manner that noise that leaks into a vehicle compartment through the
second inside air inlet is minimized.
[0009] An aspect of the invention relates to an inside air/outside
air switching device that includes: an inside air/outside air
switching case that has an outside air inlet which opens into an
engine room, a first inside air inlet which opens into a vehicle
compartment, and a second inside air inlet which opens into the
vehicle compartment and which is formed in the side wall of the
inside air/outside air switching case; an inside air/outside air
switching door that is provided in the inside air/outside air
switching case, and that switches an open inlet between the first
inside air inlet and the outside air inlet; an inside air
introduction support door that opens and closes the second inside
air inlet; and a noise insulation member that is provided in such a
manner that the noise insulation member does not interfere with the
operation of the inside air introduction support door, and that
blocks out noise which is generated in the engine room and which
proceeds from the outside air inlet toward the second inside air
inlet when the outside air inlet is open. The inside air/outside
air switching device according the aspect of the invention may
further include an air blasting unit that is provided at a position
which is downstream of the inside air introduction support door in
the direction of air flow, and that takes in the air introduced
into the inside air/outside air switching case through the inlets.
In the inside air/outside air switching device, the inside air
introduction support door may be provided at a position that is
downstream of the inside air/outside air switching door in the
direction of air flow and that is on the inner side of the second
inside air inlet, may move inward from the inner wall face of the
inside air/outside air switching case when the inside air
introduction support door opens the second inside air inlet, and
may open and close the second inside air inlet based on a change in
the pressure in the inside air/outside air switching case when the
outside air inlet is open, and the noise insulation member may be
provided at a position outside but near the operation range of the
inside air introduction support door.
[0010] According to the aspect of the invention described above,
the noise that is generated in the engine room and enters the
inside air/outside air switching case is blocked out by the noise
insulation member. With this structure, even if the second inside
air inlet is open, the noise that leaks into the vehicle
compartment is minimized.
[0011] The inside air/outside air switching device described above
may further include an air filter that is provided between the
inside air introduction support door and the air blasting unit, and
that filters the air introduced into the inside air/outside air
switching case through the inlets. The noise insulation member may
be formed of two side portions, may have a substantially L-shaped
cross section, and may be provided in such a manner that the noise
insulation member covers the inside air introduction support door.
The inside face of an end of one of the side portions may contact
the upper end of the inside air introduction support door. A small
space may be left between the lower end of the other side portion
and the air filter. In addition, a small space may be left between
each of both longitudinal ends of the side portions and the inner
wall face of the inside air/outside air switching case.
[0012] The noise that is generated in the engine room and enters
the inside air/outside air switching case through the outside air
inlet proceeds toward the second inside air inlet through the
spaces. However, a labyrinth structure is formed because the spaces
are small. Therefore, the noise that leaks into the vehicle
compartment through the second inside air inlet is minimized.
[0013] The inside air/outside air switching device described above
may further include an air volume adjustment plate that is provided
between the inside air introduction support door and the air
blasting unit, and that has a blast resistance which is
substantially equal to a blast resistance of an air filter that
filters the air introduced into the inside air/outside air
switching case through the inlets. The noise insulation member may
be formed of two side portions, may have a substantially L-shaped
cross section, and may be provided in such a manner that the noise
insulation member covers the inside air introduction support door.
The inside face of an end of one of the side portions may contact
the upper end of the inside air introduction support door. A small
space may be left between the lower end of the other side portion
and the air volume adjustment plate. In addition, a small space may
be left between each of both longitudinal ends of the side portions
and the inner wall face of the inside air/outside air switching
case.
[0014] The noise that is generated in the engine room and enters
the inside air/outside air switching case through the outside air
inlet proceeds toward the second inside air inlet through the
spaces. However, a labyrinth structure is formed because the spaces
are small. Therefore, the noise that leaks into the vehicle
compartment through the second inside air inlet is minimized.
[0015] The noise insulation member may be formed of two side
portions, may have a substantially L-shaped cross section, and may
be provided in such a manner that the noise insulation member
covers the inside air introduction support door. The inside face of
an end of one of the side portions may contact the upper end of the
inside air introduction support door. A space, through which the
air that is introduced into the inside air/outside air switching
case through the second inside air inlet flows, may be left between
the lower end of the other side portion and the upper plate of the
air blasting unit.
[0016] With this structure, the noise that is generated in the
engine room and enters the inside air/outside air switching device
through the outside air inlet is blocked out by the noise
insulation member that has the substantially L-shaped cross
section. Therefore, the noise that leaks into the vehicle
compartment through the second inside air inlet is minimized.
[0017] Side plates may be provided at respective longitudinal ends
of the noise insulation member, and each of the side plates may
connect one of the side portions to the other side portion. With
this structure, the noise that leaks into the vehicle compartment
is minimized more reliably because the length of the spaces in the
depth direction is increased.
[0018] The pressure in the inside air/outside air switching case
when the outside air inlet is open may be determined based on the
pressure of the outside air that is introduced into the inside
air/outside air switching case through the outside air inlet and
the intake negative pressure that is generated when the air
blasting unit is driven. When the pressure in the inside
air/outside air switching case is lower than the pressure of the
inside air, the inside air introduction support door may be drawn
inward from the inner wall face to open the second inside air
inlet. When the pressure in the inside air/outside air switching
case is higher than the pressure of the inside air, the inside air
introduction support door may be pushed against the inner wall face
of the inside air/outside air switching case to close the second
inside air inlet. With this structure, a device that generates
power for operating the inside air introduction support door need
not be provided, and part of the inside air is introduced into the
inside air/outside air switching case through the second inside air
inlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The features, advantages, and technical and industrial
significance of this invention will be described in the following
detailed description of example embodiments of the invention with
reference to the accompanying drawings, in which the same or
corresponding portions will be denoted by the same reference
numerals, and wherein:
[0020] FIG. 1 is a view schematically showing the overall structure
of an inside air/out side air switching device according to a first
embodiment of the invention;
[0021] FIG. 2 is a perspective view showing the appearance of a
noise insulation member according to the first embodiment of the
invention;
[0022] FIG. 3 is a partially-cutout perspective view showing the
inside air/outside air switching device according to the first
embodiment of the invention;
[0023] FIG. 4 is a front view showing the state in which an inside
air introduction support door is fitted;
[0024] FIG. 5 is a graph showing comparison between the noise level
when the noise insulation member according to the first embodiment
of the invention is provided and the noise level when no noise
insulation member is provided;
[0025] FIG. 6 is a perspective view showing the appearance of a
noise insulation member according to a second embodiment of the
invention;
[0026] FIG. 7 is a view schematically showing the overall structure
of an inside air/outside air switching device according to a third
embodiment of the invention; and
[0027] FIG. 8. is a view schematically showing the overall
structure of an inside air/outside air switching device according
to a fourth embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] Hereafter, an inside air/outside air switching device
according to a first embodiment of the invention will be described
with reference to FIGS. 1 to 5. FIG. 1 is a view schematically
showing the overall structure of the inside air/outside air
switching device. FIG. 2 is a perspective view showing the
appearance of a noise insulation member. FIG. 3 is a
partially-cutout perspective view showing the inside air/outside
air switching device. FIG. 4 is a front view showing the state in
which an inside air introduction support door is fitted.
[0029] As shown FIGS. 1 to 3, the inside air/outside air switching
device according to the first embodiment of the invention includes
an inside air/outside air switching case 10 and an air blasting
unit 20. The inside air/outside air switching device is provided at
the front portion of a vehicle compartment of a vehicle. The inside
air/outside air switching device is arranged below a dashboard and
on the side of a front passenger seat. The inside air/outside air
switching case 10 is formed of a case made of synthetic resin, and
the air blasting unit 20 is connected to the bottom of the inside
air/outside air switching case 10. The inner space of the inside
air/outside air switching case 10 is communicated with a
bell-mouthed inlet 21 of the air blasting unit 20.
[0030] The inside air/outside air switching case 10 has a first
inside air inlet 11 and a second inside air inlet 17 (described
later in detail) through which the air in the vehicle compartment
is introduced into the inside air/outside air switching case 10,
and an outside air inlet 12 through which the air outside the
vehicle compartment is introduced into the inside air/outside air
switching case 10. The first inside air inlet 11 and the second
inside air inlet 17 open into the vehicle compartment, and the
outside air inlet 12 opens into the engine room. The vehicle
compartment and the engine room are separated from each other by a
dash panel D.
[0031] A rotary door 13, which is an inside air/outside air
switching door that is used to switch the air that is introduced
into the inside air/outside air switching case 10 between the
inside air and the outside air, is provided at a position that is
downstream of the first inside air inlet 11 and the outside air
inlet 12 in the direction of air flow. The rotary door 13 is
arranged so as to pivot about right and left pivot shafts 13c. The
rotary door 13 is formed of a peripheral wall 13a having an
arc-shaped cross section, and fan-shaped side plates 13b that are
formed at respective sides of the peripheral wall 13a.
[0032] The peripheral wall 13a pivots about the pivot shafts 13c.
End portions of the pivot shafts 13c protrude from the right and
left side plates 13b, respectively, outward in the axial direction
of the pivot shafts 13c. The right and left pivot shafts 13c are
rotatably supported by bearing holes 10a formed in the inside
air/outside air switching case 10 (see FIG. 3). The pivot shafts
13c are allowed to rotate within a range of approximately 70
degrees.
[0033] Flanges 13d are formed on the entire ends of the peripheral
wall 13a and flanges 13e are formed on the entire ends of the side
plates 13b. The flanges 13d are formed on the peripheral wall 13a
at the ends in the circumferential direction of the peripheral wall
13a, and project from the ends outward in the radial direction. The
flanges 13e are formed at both ends of each of the right and left
side plates 13b, and project from the ends outward in the axial
direction of the pivot shafts 13c.
[0034] The rotary door 13 may be made of resin, for example,
polypropylene, and is easily produced by forming the
above-described portions 13a to 13e integrally with each other.
Thin gaskets 14 and 15 are fixed all over the respective faces of
the flanges 13d and 13e with, for example, an adhesive agent. The
gaskets 14 and 15 provide airtight sealing when the first inside
air inlet 11 or the outside air inlet 12 is closed by the rotary
door 13.
[0035] Thermoplastic elastomer is preferably used as the material
for the gaskets 14 and 15. The thermoplastic elastomer is an
elastic body that exhibits rubber elasticity at ordinary
temperatures and that softens and exhibits liquidity
(thermoplasticity) at high temperatures. Therefore, the
thermoplastic elastomer is formed into shapes in a manner similar
to a manner in which ordinary thermoplastic resin is formed into
shapes. Therefore, the gaskets 14 and 15 may be formed integrally
with the rotary door 13.
[0036] The first inside air inlet 11 has a peripheral portion
opening 11a that faces the peripheral wall 13a of the rotary door
13 and side portion openings 11b that extend from the peripheral
portion opening ha toward the pivot shafts 13c. That is, when the
rotary door 13 opens the first inside air inlet 11, not only a
portion that corresponds to the peripheral wall 13a of the rotary
door 13 but also portions that correspond to the side plates 13b of
the rotary door 13 are open. In contrast, the outside air inlet 12
is formed only of a peripheral portion opening that faces the
peripheral wall 13a of the rotary door 13.
[0037] The up-down direction, the right-left direction, and the
front-rear direction shown in FIGS. 1 and 3 show the directions of
the inside air/outside air switching device when the inside
air/outside air switching device is mounted in the vehicle. The
pivot shafts 13c for the rotary door 13 are arranged at
substantially the center of the inside air/outside air switching
case 10 in the front-rear direction and below the inlets 11 and 12.
Sealing faces 10b and 10c are formed at positions posterior to the
pivot shafts 13c and sealing faces 10d and 10e are formed at
positions anterior to the pivot shafts 13c. The sealing faces 10b,
10c, 10d and 10e are inclined downward toward the pivot shafts 13c.
Sealing faces 10f and 10g are formed at positions above the pivot
shafts 13c.
[0038] The sealing faces 10b to 10g are formed in such a manner
that flanges 13d and 13e contact the sealing faces 10d, 10e, 10f
and 10g when the rotary door 13 is at a position at which the
inside air is introduced into the inside air/outside air switching
case 10 (position indicated by two-dot chain lines in FIG. 1), and
the flanges 13d and 13e contact (are brought into surface contact
with) the sealing faces 10b, 10c, 10f and 10g when the rotary door
13 is at a position at which the outside air is introduced into the
inside air/outside air switching case 10 (position indicated by
solid lines in FIG. 1).
[0039] The inside air/outside air switching case 10 having the
above-described structure includes at least two cases 10j and 10k
that are separately formed. The inside air/outside air switching
case 10 is formed by arranging the separate cases 10j and 10k next
to each other in the longitudinal direction of the rotary door 13,
that is, the right-left direction of the vehicle and then
connecting the cases 10j and 10k integrally with each other. The
sealing faces 10b to 10g are formed integrally with the inside
air/outside air switching case 10.
[0040] A switching link member 16 made of resin (see FIG. 3) is
connected integrally with one end of the pivot shaft 13c of the
rotary door 13. A manual operation force, which is applied to an
inside air/outside air switching operation member (e.g. manual
operation lever) provided in an air-conditioning operation panel
(not shown), is transmitted from the switching link member 16 to
the pivot shaft 13c via, for example, a cable to cause the rotary
door 13 to pivot about the pivot shafts 13c.
[0041] Alternatively, an actuator (e.g. motor) may be electrically
actuated with the use of an inside air/outside air changeover
switch in the air-conditioning operation panel, and the switching
link member 16 may be operated by the actuator so that the rotary
door 13 pivots about the pivot shafts 13c.
[0042] An air filter 30 is provided in the inside air/outside air
switching device. In the air filter 30, a filter member formed of,
for example, corrugated Japanese paper or a porous urethane foam is
supported by a frame made of resin. The air filter 30 has a flat
plate shape as shown in FIG. 1, and removes dust in the air. When
required, the filter member may be provided with an absorbent, for
example, activated charcoal, which absorbs malodorous components.
In this way, the filter member offers deodorization
performance.
[0043] In the inside air/outside air switching case 10, the air
filter 30 is provided at a position downstream of the pivot shafts
13c of the rotary door 13 in the direction of air flow so that the
air filter 30 does not interfere with the pivot motion of the
rotary door 13. The air blasting unit 20 includes a blast fan 22
formed of a centrifugal multiblade blower, a drive motor 23, and a
casing 24. The casing 24 is made of resin material, and formed in a
scroll shape.
[0044] The blast fan 22 is driven by the motor 23 so that the air
taken in the blast fan 22 through the inlet 21 flows outward in the
radial direction of the blast fan 22 as indicated by an arrow A. An
air outlet 25 of the casing 24 is connected to an air-conditioning
duct (not shown). The blast fan 22 and the motor 23 may be included
in an air blasting unit according to the invention.
[0045] A heat exchanger for cooling air, a heat exchanger for
heating air, etc. are housed in the air-conditioning duct. The air
delivered from the air blasting unit 20 is cooled, dehumidified,
and re-heated while passing through the air-conditioning duct. In
this way, the temperature of the air is adjusted. Then, the air is
introduced into the vehicle compartment.
[0046] The second inside air inlet 17 is formed in the inside
air/outside air switching case 10 at a side wall on the vehicle
front side. In addition, the second inside air inlet 17 is formed
at a position below the outside air inlet 12. That is, the second
inside air inlet 17 is formed at a position between the rotary door
13 and the air filter 30. An inside air introduction support door
18, which opens and closes the second inside air inlet 17, is
arranged on the inner side of the second inside air inlet 17, that
is, at a position closer to the rear of the vehicle than the second
inside air inlet 17. The inside air introduction support door 18 is
arranged in such a manner that the inside air introduction support
door 18 does not interfere with the pivot motion of the rotary door
13.
[0047] As shown in FIGS. 1 and 4, the inside air introduction
support door 18 includes a door member 18a, which is formed of a
thin rectangular plate, and a pivot shaft 18c. A gasket 18b is
fitted on a face of the door member 18a, which faces the second
inside air inlet 17. The gasket 18b provides airtight sealing when
the inside air introduction support door 18a contacts a sealing
face 17a (see FIG. 1) in the side wall, which defines the second
inside air inlet 17. Therefore, for example, porous elastic
material, for example, a urethane foam or the above-described
thermoplastic elastomer may be used as the material for the gasket
18b.
[0048] Both ends of the pivot shaft 18c are rotatably supported by
bearing holes 10h that are formed in the inside air/outside air
switching case 10, at positions above the second inside air inlet
17. When the operation of the blast fan 22 does not operate, the
inside air introduction support door 18 according to the first
embodiment of the invention is oriented in the vertical direction
(direction of gravitational force) as indicated by solid lines in
FIG. 1 so as to close the second inside air inlet 17.
[0049] The inside air introduction support door 18 opens and closes
the second inside air inlet 17 in response to changes in the
pressure in the inside air/outside air switching case 10. In the
outside air mode in which the outside air inlet 12 is opened and
the first inside air inlet 11 is closed by the rotary door 13, the
pressure in the inside air/outside air switching case 10 is
determined based on the pressure of the outside air that is
introduced into the inside air/outside air switching case 10
through the outside air inlet 12, that is, the pressure of the
outside air, which is influenced by the dynamic pressure that is
generated when the vehicle travels, and the intake negative
pressure that is generated when the blast fan 22 is driven.
[0050] More specifically, when the blast fan 22 rotates at a high
speed, the intake negative pressure increases and the pressure in
the inside air/outside air switching case 10 decreases. When the
vehicle travels at a high speed, the dynamic pressure increases and
the pressure in the inside air/outside air switching case 10
increases. When the vehicle compartment needs to be warmed up
rapidly, for example, when a heater is turned on in winter, the
voltage that is supplied to the drive motor 23 is maximized to
maximize the rotational speed of the blast fan 22 (to maximize the
volume of air delivered from the blast fan 22). In this way, the
maximum heating capacity is utilized. As a result, the pressure in
the inside air/outside air switching case 10 falls below the
pressure in the vehicle compartment.
[0051] That is, the intake negative pressure is introduced into the
area near the inside air introduction support door 18, which causes
a pressure difference between the pressure in the area near the
inside air introduction support door 18 and the pressure in the
vehicle compartment, that is, the pressure outside the inside
air/outside air switching case 10. Namely, a pressure change is
caused in the inside air/outside air switching case 10. With the
use of this pressure difference, the inside air introduction
support door 18 pivots inward from the inner wall face of the
inside air/outside air switching case 10 as indicated by two dot
chains line in FIG. 1. As a result, the second inside air inlet 17
is opened.
[0052] In other words, when the pressure in the inside air/outside
air switching case 10 is lower than the pressure of the inside air,
the inside air introduction support door 18 moves away from the
second inside air inlet 17 and drawn inward from the inner wall
face of the inside air/outside air switching case 10. As a result,
the second inside air inlet 17 is opened. Thus, part of the inside
air is drawn into the inside air/outside air switching case 10
through the second inside air inlet 17. The temperature of the
inside air is higher than the low temperature of the outside air in
winter. Therefore, if part of the inside air is mixed with the
outside air, the temperature of the air at an inlet of the heat
exchanger for heating air provided in the air-conditioning duct
increases. As a result, the temperature of the air that is warmed
while the air passes through the heat exchanger for heating is made
higher than that when only the outside air is introduced into the
inside air/outside air switching case 10. As a result, the heating
efficiency is enhanced.
[0053] On the other hand, when the pressure in the inside
air/outside air switching case 10 is higher than the pressure of
the inside air, the inside air introduction support door 18 is
pushed against the inner wall face of the inside air/outside air
switching case 10, more specifically, the inner wall face at a
portion around the second inside air inlet 17. As a result, the
second inside air inlet 17 is closed. Thus, it is possible to avoid
the situation where the low temperature outside air passes through
the second inside air inlet 17 and directly flows into the vehicle
compartment while the vehicle compartment is heated in the outside
air mode.
[0054] The opening amount of the inside air introduction support
door 18, in other words, the volume of inside air that is
introduced into the inside air/outside air switching case 10
through the second inside air inlet 17 may be adjusted based on the
relationship between the weight (gravity) of the inside air
introduction support door 18 and the pressure of the air delivered
from the blast fan 22. Accordingly, the required volume of inside
air that is introduced into the inside air/outside air switching
case 10 may be ensured by changing the weight of the inside air
introduction support door 18.
[0055] A noise insulation member 19 is provided at a position that
is outside but near the operation range of the inside air
introduction support door 18. The noise insulation member 19 blocks
out the noise generated in the engine room, which proceeds from the
outside air inlet 12 toward the second inside air inlet 17 when the
outside air inlet 12 is open.
[0056] As shown in FIGS. 1, 2 and 4, the cross section of the noise
insulation member 19 is in a substantially L-shape. The noise
insulation member 19 is formed of a side portion 19a and another
side portion 19b. The inner side of the end portion of the side
portion 19a contacts the inside air introduction support door 18 at
a portion near the top of the pivot shaft 18c, that is, the upper
end of the inside air introduction support door 18. A small space
S1 is left between the lower end of the side portion 19b and the
upper face of the air filter 30 (see FIG. 1).
[0057] The space S1 left between the upper face of the air filter
30 and the noise insulation member 19 is determined in such a
manner that the air filter 30 is attached to and detached from the
inside air/outside air switching case 10 without hindrance. In
addition, a small space S1 is left between each of both ends of the
noise insulation member 19, that is, the side portions 19a and 19b,
and the inner wall of the inside air/outside air switching case 10
(see FIG. 4). That is, the noise insulation member 19 is formed so
as to cover the inside air introduction support door 18. The space
S1 left between the inner wall of the inside air/outside air
switching case 10 and the noise insulation member 19 may be smaller
than the space between the side portion 19b and the upper face of
the air filter 30.
[0058] With this structure, the noise that is generated in the
engine room and that enters the inside air/outside air switching
case 10 through the outside air inlet 12 is blocked out by the
noise insulation member 19. The noise generated in the engine room
leaks toward the second inside air inlet 17 through the small
spaces S1. However, the noise that leaks toward the second inside
air inlet 17 is minimized because a labyrinth structure is formed
due to the small spaces S1.
[0059] Next, the operation of the inside air/outside air switching
device having the above-described structure will be described. The
air that is introduced into the inside air/outside air switching
case 10 may be switched between the inside air and the outside air
by pivoting the rotary door 13 about the pivot shafts 13c. To
select the outside air introduction mode, the rotary door 13 is
pivoted to the position indicated by the solid lines in FIG. 1
(FIG. 3 shows the case where the rotary door 13 is at the position
at which the outside air is introduced into the inside air/outside
air switching case 10).
[0060] Thus, the peripheral wall 13a of the rotary door 13 closes
the peripheral portion opening 11a of the first inside air inlet
11, and the side plates 13b of the rotary door 13 close the side
portion openings 11b of the first inside air inlet 11. At the same
time, the peripheral wall 13a of the rotary door 13 moves away from
the airflow path on the outside air inlet 12 side. As a result, the
outside air inlet 12 is fully open.
[0061] The gaskets 14 and 15 fixed to the flanges 13d and 13e of
the rotary door 13 are pushed against (brought into surface contact
with) the sealing faces 10b, 10c, 10f and 10g of the inside
air/outside air switching case 10. Therefore, surface-sealing is
provided between the entire ends of the rotary door 13 and the
inside air/outside air switching case 10.
[0062] The space on the inner side of the rotary door 13 is
entirely communicated with the outside air inlet 12 and a space
upstream of the air filter 30 in the direction of air flow.
Therefore, the outside air, which is introduced into the inside
air/outside air switching case 10 through the outside air inlet 12
when the blast fan 22 is driven, flows through the space on the
inner side of the rotary door 13 and uniformly introduced into the
air filter 30.
[0063] Next, the introduced outside air passes through the air
filter 30, and fine dust, malodorous components, etc. are absorbed
in the air filter 30 and therefore removed from the air. Then, the
introduced outside air from which fine dust, malodorous components,
etc. are removed is drawn into the air blasting unit 20 through the
inlet 21 and delivered toward the air-conditioning duct under
pressure.
[0064] The intake negative pressure is introduced into the area
near the air filter 30 and the inside air introduction support door
18 when the blast fan 22 is driven, which causes a pressure
difference between the pressure in this area and the pressure in
the vehicle compartment, that is, the pressure outside the inside
air/outside air switching case 10. Due to this pressure difference,
the inside air introduction support door 18 opens the second inside
air inlet 17. That is, the inside air introduction support door 18
pivots to the position indicated by the two-dot chain lines in FIG.
1. As a result, the outside air is introduced into the inside
air/outside air switching case 10 through the outside air inlet 12
and part of the inside air is introduced into the inside
air/outside air switching case 10 through the second inside air
inlet 17.
[0065] To select the inside air introduction mode, the rotary door
13 is pivoted clockwise by approximately 70 degrees from the
position indicated by the solid lines in FIG. 1 to the position
indicated by the two-dot chain lines in FIG. 1. Thus, the gaskets
14 and 15 fixed to the flanges 13d and 13e of the rotary door 13
are pushed against (brought into surface contact with) the sealing
faces 10d, 10e, 10f and 10g of the inside air/outside air switching
case 10. Therefore, surface-sealing is provided between the entire
ends of the rotary door 13 and the inside air/outside air switching
case 10.
[0066] As a result, the outside air inlet 12 is closed and the
first inside air inlet 11 is fully open. The inside air, which is
introduced into the inside air/outside air switching case 10
through the first inside air inlet 11 when the blast fan 22 is
driven, flows through the space on the inner side of the rotary
door 13 and is uniformly introduced into the air filter 30.
[0067] The introduced inside air passes through the air filter 30,
and fine dust, malodorous components, etc. are absorbed in the air
filter 30 and therefore removed from the air. Then, the introduced
inside air from which fine dust, malodorous components, etc. are
removed is drawn into the air blasting unit 20 through the inlet 21
and delivered toward the air-conditioning duct under pressure.
[0068] In the inside air introduction mode as well the intake
negative pressure is introduced into the area near the air filter
30 and the inside air introduction support door 18 when the blast
fan 22 is driven, which causes a pressure difference between the
pressure in the area and the pressure in the vehicle compartment,
that is, the pressure outside the inside air/outside air switching
case 10. Due to this pressure difference, the inside air
introduction support door 18 pivots to open the second inside air
inlet 17. As a result, the inside air is introduced into the inside
air/outside air switching case 10 through the first inside air
inlet 11 and part of the inside air is introduced into the inside
air/outside air switching case, 10 through the second inside air
inlet 17.
[0069] Next, the noise insulating effect provided by the noise
insulation member 19 will be described. FIG. 5 is a graph showing
comparison between the noise level when the noise insulation member
is provided and the noise level when no noise insulation member is
provided. More specifically, FIG. 5 shows the comparison of the
above-described noise levels near the ear of an occupant in the
front passenger seat in the outside air introduction mode, in the
case where the inside air/outside air switching device is mounted
in the vehicle. A solid line in FIG. 5 shows the characteristic of
the noise level when the noise insulation member 19 is provided at
a position that is outside but near the operation range of the
inside air introduction support door 18.
[0070] A dashed line in FIG. 5 shows the characteristic of the
noise level when no noise insulation member 19 is provided. The
graph shows that provision of the noise insulation member 19
decreases the noise level in the frequency range from approximately
1200 Hz to approximately 2500 Hz.
[0071] When the inside air/outside air switching device having the
above-described structure is in the outside air introduction mode,
the outside air is introduced into the inside air/outside air
switching case 10 through the outside air inlet 12 and part of the
inside air is introduced into the inside air/outside air switching
case 10 through the second inside air inlet 17. Therefore, the
noise generated in the engine room enters the inside air/outside
air switching case 10 through the outside air inlet 12 and proceeds
toward the second inside air inlet 17. However the noise generated
in the engine room, which enters the inside air/outside air
switching case 10 through the outside air inlet 12, is blocked out
by the noise insulation member 19.
[0072] The noise generated in the engine room leaks toward the
second inside air inlet 17 through the small spaces S1. However,
the noise that leaks toward the second inside air inlet 17 is
minimized because the labyrinth structure is formed due to the
small spaces S1. Thus, even if the second inside air inlet 17 is
open, the noise that leaks into the vehicle compartment is
minimized.
[0073] In addition, if the inside air introduction support door 18
is opened with the use of the intake negative pressure that is
generated when the blast fan 22 is driven, part of the inside air
is introduced into the inside air/outside air switching case 10
through the second inside air inlet 17 not only in the outside air
introduction mode but also in the inside air introduction mode.
Also, a component used to open and close the inside air
introduction support door is, for example, a link member, is no
longer necessary, which reduces the component cost.
[0074] Next, a second embodiment of the invention will be
described. FIG. 6 is a perspective view showing the appearance of a
noise insulation member according to the second embodiment of the
invention. As shown in FIG. 6, the noise insulation member 19
according to the second embodiment of the invention is provided
with side plates 19c that are arranged at respective longitudinal
ends of the noise insulation member 19, and that connect the side
portion 19a and the side portion 19b to each other. That is, the
noise insulation member 19 is provided with side walls formed of
the side plates 19c.
[0075] With this structure, the length of the space S1 between the
upper face of the air filter 30 and the noise insulation member 19
in the depth direction and the length of the space S1 between the
noise insulation member 19 and the inner wall of the inside
air/outside air switching case 10 in the depth direction are
increased. Therefore, the noise that is generated in the engine
room that enters the inside air/outside air switching case 10
through the outside air inlet 12 is reduced. Thus, it is possible
to reduce the noise that leaks into the vehicle compartment through
the second inside air inlet 17.
[0076] Next, a third embodiment of the invention will be described.
In the embodiments of the invention described above, the air filter
30 is provided between the inside air introduction support door 18
and the air blasting unit 20. Instead of the air filter 30, an air
volume adjustment plate 40 may be provided. FIG. 7 is a view
schematically showing the overall structure of an inside
air/outside air switching device according to the third embodiment
of the invention. In the inside air/outside air switching case 10
according to the third embodiment of the invention, the air volume
adjustment plate 40 is provided at a position that is downstream of
the inside air introduction support door 18 in the direction of air
flow, as shown in FIG. 7.
[0077] The air volume adjustment plate 40 is used as a substitute
for the air filter 30 after the air filter 30 is removed from the
inside air/outside air switching case 10. The air volume adjustment
plate 40 is a pressure loss adjustment plate that is used to adjust
the volume of the intake air that is introduced through the inlets
11, 12 and 17. In the third embodiment of the invention, the air
volume adjustment plate 40 has a draft resistance that is
substantially equal to the draft resistance of the air filter 30.
That is, the air volume adjustment plate 40 is formed in such a
manner that the draft resistance thereof is substantially equal to
the draft resistance of the air filter 30.
[0078] Therefore, the air volume adjustment plate 40 is formed in
such a manner that the air volume adjustment plate 40 is easily
attached to and detached from the inside air/outside air switching
case 10 as in the case of the air filter 30, and is formed of a
porous plate 41 that has a large number of draft holes 42.
Accordingly, if the air volume adjustment plate 40 is arranged in
place of the air filter 30 after the air filter 40 is removed, the
volume of the air that passes through the air volume adjustment
plate 40 is adjusted in a manner substantially same as that when
the air filter 30 is arranged.
[0079] As in the embodiments of the invention described above, the
noise insulation member 19 is arranged in such a manner that the
inner side of the end portion of the side portion 19a contacts the
inside air introduction support door 18 at a portion near the top
of the pivot shaft 18c, that is, the upper end of the inside air
introduction support door 18. A small space S1 is left between the
lower end of the side portion 19b and the upper face of the air
volume adjustment plate 40 (see FIG. 7).
[0080] The amount of space S1 left between the upper face of the
air volume adjustment plate 40 and the noise insulation member 19
is determined in such a manner that the air volume adjustment plate
40 is attached to and detached from the inside air/outside air
switching case 10 without hindrance. Thus, the noise that is
generated in the engine room that enters the inside air/outside air
switching case 10 through the outside air inlet 12 is blocked out
by the noise insulation member 19. A small space S1 is left between
each of the both ends of the noise insulation member 19, that is,
the side portions 19a and 19b, and the inner wall of the inside
air/outside air switching case 10 (see FIG. 4), as in the
above-described embodiments.
[0081] A fourth embodiment of the invention will be described. In
the embodiments of the invention described above, the air filter 30
or the air volume adjustment plate 40 is arranged between the
inside air introduction support door 18 and the air blasting unit
20. However, the inside air/outside air switching case 10 that
includes neither the air filter 30 nor the air volume adjustment
plate 40 may be used. FIG. 8 is a view schematically showing the
overall structure of the inside air/outside air switching device
according to the fourth embodiment of the invention.
[0082] As shown in FIG. 8, the air blasting unit 20 is provided at
a position that is directly downstream of the inside air
introduction support door 18 in the direction of air flow. For
example, the inside air/outside air switching case 10 according to
the fourth embodiment of the invention is used when the air filter
30 is provided in the air-conditioning duct (not shown) connected
to a downstream-side portion of the air blasting unit 20.
[0083] Accordingly, a space S2 is left between the lower end of the
side portion 19b of the noise insulation member 19 according to the
fourth embodiment of the invention and an upper plate 24a of the
casing 24 of the air blasting unit 20. The space S2 is larger than
the small space S1.
[0084] The space S2 according to the fourth embodiment of the
invention is set in such a manner that the intake air introduced
into the inside air/outside air switching case 10 through the
second inside air inlet 17 flows toward the inlet 21 of the casing
24. Therefore, when the second inside air inlet 17 is opened in
response of a change in the pressure in the inside air/outside air
switching case 10, the intake air introduced into the inside
air/outside air switching case 10 through the second inside air
inlet 11 is drawn by the blast fan 22.
[0085] With the inside air/outside air switching device having the
structure described above, the noise that is generated in the
engine room that enters the inside air/outside air switching case
10 through the outside air inlet 12 is blocked out by the noise
insulation member 19 that has the substantially L-shaped cross
section. Accordingly, it is possible to reduce the noise that leaks
into the vehicle compartment through the second inside air inlet
17.
[0086] In the embodiments of the invention described above, the
noise insulation member 19 is larger than the inside air
introduction support door 18 when viewed in the front-rear
direction of the vehicle. Alternatively, the noise insulation
member 19 may be equal to or smaller than the inside air
introduction support door 18 when viewed in the front-rear
direction of the vehicle.
[0087] In the embodiments of the invention described above, the
inside air introduction support door 18 is formed by forming the
door member 18a and the pivot shaft 18c integrally with each other
and fitting the gasket 18b to the door member 18a. Alternatively,
the inside air introduction support door 18 may be formed by
forming material, for example, thermoplastic elastomer, in an
elastically deformable sheet shaped plate door.
[0088] More specifically, a plate door is formed of a single sheet,
and only one face of an upper portion of the sheet is fixed to an
upper portion of the inner wall face around the second inside air
inlet 17. Thus, the second inside air inlet 17 may be opened and
closed in response to a change in the pressure in the inside
air/outside air switching case 10.
[0089] In the embodiments of the invention described above, the
inside air introduction support door 18 may be opened and closed
based on an intake negative pressure generated by the blast fan 22.
Alternatively, the inside air introduction support door 18 may be
opened and closed by an actuator, for example, a servo motor.
[0090] While the invention has been described with reference to
example embodiments thereof, it is to be understood that the
invention is not limited to the example embodiments or
constructions. To the contrary, the invention is intended to cover
various modifications and equivalent arrangements. In addition,
while the various elements of the example embodiments are shown in
various combinations and configurations, which are example, other
combinations and configurations, including more, less or only a
single element, are also within the scope of the invention.
* * * * *