U.S. patent application number 09/808933 was filed with the patent office on 2001-09-20 for automotive climate control system.
Invention is credited to Itoh, Satoshi, Kuroda, Yasutaka, Tomatsu, Yoshitaka, Yamaguchi, Motohiro, Yamanaka, Yasushi.
Application Number | 20010022092 09/808933 |
Document ID | / |
Family ID | 18596613 |
Filed Date | 2001-09-20 |
United States Patent
Application |
20010022092 |
Kind Code |
A1 |
Yamaguchi, Motohiro ; et
al. |
September 20, 2001 |
Automotive climate control system
Abstract
An automotive climate control system is disclosed. As long as an
ignition switch is off, a bypass (14) is closed (in this state, a
ratio between warm air and cool air is a maximum when the
automotive climate control system is activated.), the blowout is
set to defrost mode and the introduced air is set to external air
mode regardless of the preceding modes of blowout and introduced
air (when the ignition switch is on). As a result, the refrigerant
leaking from an evaporator (12) flows to an external air inlet (23)
smaller in air resistance. Even in the case where the ignition
switch is off, therefore, the leaking refrigerant is prevented from
flowing into the cabin.
Inventors: |
Yamaguchi, Motohiro;
(Hoi-gun, JP) ; Itoh, Satoshi; (Kariya-city,
JP) ; Tomatsu, Yoshitaka; (Chiryu-city, JP) ;
Kuroda, Yasutaka; (Anjo-city, JP) ; Yamanaka,
Yasushi; (Nakashima-gun, JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, PLC
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
18596613 |
Appl. No.: |
09/808933 |
Filed: |
March 15, 2001 |
Current U.S.
Class: |
62/244 |
Current CPC
Class: |
F25B 2309/061 20130101;
B60H 1/00978 20130101; B60H 1/00735 20130101 |
Class at
Publication: |
62/244 |
International
Class: |
B60H 001/32 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2000 |
JP |
2000-079356 |
Claims
1. An automotive climate control system comprising: an
air-conditioning casing (11) for passing the air to be blown out
into the cabin; a first heat exchanger (12) arranged in said
air-conditioning casing (11) for exchanging heat between a
refrigerant and the air; a face opening (17) arranged downstream of
said first heat exchanger (12) in the air flow for blowing out the
air to the faces of the occupants in the cabin; a foot opening (18)
arranged downstream of said first heat exchanger (12) in the air
flow for blowing out the air to the feet of the occupants in the
cabin; a defroster opening (19) arranged downstream of said first
heat exchanger (12) in the air flow for blowing out the air to the
vehicle windshield glass; an internal air inlet (22) arranged
upstream of said first heat exchanger (12) in the air flow for
introducing the air from the cabin; and an external air inlet (23)
arranged upstream of said first heat exchanger (12) in the air flow
for introducing the air from outside the cabin; wherein when the
electrical equipment mounted on the vehicle is not supplied with
power, among a first air path (A) leading from the first heat
exchanger (12) to the face opening (17), a second air path (B)
leading from the first heat exchanger (12) to the foot opening (18)
and a third air path (C) leading from the first heat exchanger (12)
to the defroster opening (19), only the air path (C) having a
larger air resistance than an air path (E) leading from the first
heat exchanger (12) to the external air inlet (23) passes air
therethrough while, at the same time, air is passed through the air
path (E) leading from the first heat exchanger (12) to the external
air inlet (23).
2. An automotive climate control system comprising: an
air-conditioning casing (11) for passing the air to be blown out
into the cabin therethrough; a first heat exchanger (12) arranged
in the air-conditioning casing (11) for exchanging heat between the
refrigerant and the air; a face opening (17) arranged downstream of
the first heat exchanger (12) in the air flow for blowing out the
air to the faces of the occupants in the cabin; a foot opening (18)
arranged downstream of the first heat exchanger (12) in the air
flow for blowing out the air to the feet of the occupants in the
cabin; a defroster opening (19) arranged downstream of the first
heat exchanger (12) for blowing out the air to the vehicle
windshield glass; an internal air inlet (22) arranged upstream of
the first heat exchanger (12) in the air flow for introducing the
air from the cabin; and an external air inlet (23) arranged
upstream of the first heat exchanger (12) in the air flow for
introducing the air from outside the cabin; wherein as long as the
electrical equipment mounted on the vehicle is not supplied with
power, among a first air path (A) leading from the first heat
exchanger (12) to the face opening (17), a second air path (B)
leading from the first heat exchanger (12) to the foot opening (18)
and a third air path (C) leading from the first heat exchanger (12)
to the defroster opening (19), only the air path (C) having the
largest air resistance passes the air while, at the same time, air
is passed through an air path (E) leading from the first heat
exchanger (12) to the external air inlet (23).
3. An automotive climate control system comprising an
air-conditioning casing (11) for passing the air to be blown out
into the cabin therethrough; a first heat exchanger (12) arranged
in the air-conditioning casing (11) for exchanging heat between the
refrigerant and the air; a face opening (17) arranged downstream of
the first heat exchanger (12) in the air flow for blowing out the
air to the faces of the occupants in the cabin; a foot opening (18)
arranged downstream of the first heat exchanger (12) in the air
flow for blowing out the air to the feet of the occupants in the
cabin; a defroster opening (19) arranged downstream of the first
heat exchanger (12) for blowing out the air to the vehicle
windshield glass; an internal air inlet (22) arranged upstream of
the first heat exchanger (12) in the air flow for introducing the
air from the cabin; and an external air inlet (23) arranged
upstream of the first heat exchanger (12) for introducing the air
from outside the cabin; wherein, as long as the electrical
equipment mounted on the vehicle is not supplied with power, the
air path (C) leading from the first heat exchanger (12) to the
defroster opening (19) passes air therethrough while, at the same
time, air is passed through an air path (E) leading from the first
heat exchanger (12) to the external air inlet (23).
4. An automotive climate control system comprising an
air-conditioning casing (11) for passing the air to be blown out
into the cabin therethrough; a first heat exchanger (12) arranged
in the air-conditioning casing (11) for exchanging heat between the
refrigerant and the air; a face opening (17) arranged downstream of
the first heat exchanger (12) in the air flow for blowing out the
air to the faces of the occupants in the cabin; a foot opening (18)
arranged downstream of the first heat exchanger (12) in the air
flow for blowing out the air to the feet of the occupants in the
cabin; a defroster opening (19) arranged downstream of the first
heat exchanger (12) for blowing out the air to the vehicle
windshield glass; an internal air inlet (22) arranged upstream of
the first heat exchanger (12) in the air flow for introducing the
air from the cabin; and an external air inlet (23) arranged
upstream of the first heat exchanger (12) for introducing the air
from outside the cabin; wherein, as long as the electrical
equipment mounted on the vehicle is not supplied with power, among
a first air path (A) leading from the first heat exchanger (12) to
the face opening (17), a second air path (B) leading from the first
heat exchanger (12) to the foot opening (18) and a third air path
(C) leading from the first heat exchanger (12) to the defroster
opening (19), only the air path (C) passes the air therethrough,
while at the same time air is passed through an air path (E)
leading from the first heat exchanger (12) to the external air
inlet (23).
5. An automotive climate control system comprising an
air-conditioning casing (11) for passing the air to be blown out
into the cabin therethrough; a first heat exchanger (12) arranged
in the air-conditioning casing (11) for exchanging heat between the
refrigerant and the air; a face opening (17) arranged downstream of
the first heat exchanger (12) in the air flow for blowing out the
air to the faces of the occupants in the cabin; a foot opening (18)
arranged downstream of the first heat exchanger (12) in the air
flow for blowing out the air to the feet of the occupants in the
cabin; a defroster opening (19) arranged downstream of the first
heat exchanger (12) for blowing out the air to the vehicle
windshield glass; an internal air inlet (22) arranged upstream of
the first heat exchanger (12) in the air flow for introducing the
air from the cabin; and an external air inlet (23) arranged
upstream of the first heat exchanger (12) for introducing the air
from outside the cabin; wherein, as long as the electrical
equipment mounted on the vehicle is not supplied with power, a
first air path (A) leading from the first heat exchanger (12) to
the face opening (17), a second air path (B) leading from the first
heat exchanger (12) to the foot opening (18) and a third air path
(C) leading from the first heat exchanger (12) to the defroster
opening (19) are all closed, while at the same time air is passed
through an air path (E) leading from the first heat exchanger (12)
to the external air inlet (23).
6. An automotive climate control system according to claim 1,
wherein a second heat exchanger (13) for heating the air is
arranged between the first heat exchanger (12) and the three
openings (17 to 19) in the air-conditioning casing (11), and as
long as the electric equipment mounted on the vehicle is not
supplied with power, the air flowing from the first heat exchanger
(12) toward the second heat exchanger (13) is passed in its
entirety through the second heat exchanger (13).
7. An automotive climate control system according to claim 1,
wherein said air-conditioning casing (11) includes therein: a
second heat exchanger (13) arranged between the first heat
exchanger (12) and the three openings (17 to 19) for heating the
air; a bypass (14) for causing the air passing from the first heat
exchanger (12) toward the second heat exchanger (13) to bypass the
second heat exchanger (13); and a bypass amount adjusting means
(15) for adjusting the air passed through the bypass (14); wherein
the bypass amount adjusting means (15) closes the bypass (14) in
the case where the electrical equipment mounted on the vehicle is
not supplied with power.
8. An automotive climate control system according to claim 1,
wherein a fluid having a higher density than air is used as a
refrigerant, and the external air inlet (23) is arranged at a
position lower than the defroster opening (19).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an automotive climate
control system or, in particular, to an automotive climate control
system using carbon dioxide or a hydrocarbon compound (combustible
refrigerant) such as propane as a refrigerant.
[0003] 2. Description of the Related Art
[0004] In the invention of an automotive climate control system
using a combustible refrigerant such as propane disclosed in
Japanese Unexamined Patent Publication (Kokai) No. 9-11734, whether
the refrigerant is leaking or not is detected by a sensor and, in
the case where a refrigerant leakage is detected, an electric
actuator such as a servo motor is activated to open an external air
inlet to introduce air from outside the cabin thereby to prevent
the leaking refrigerant from flowing into the cabin.
[0005] With the aforementioned invention, however, as long as the
vehicle is stationary with the ignition switch off, power cannot be
supplied to the sensor and the electric actuator. In the case where
the refrigerant leaks out while the vehicle is stationary,
therefore, action against it cannot be taken.
[0006] This inconvenience may be obviated by providing means for
supplying power constantly to the sensor and the electric actuator
at the sacrifice of an increased power load on the battery.
SUMMARY OF THE INVENTION
[0007] In view of the aforementioned fact, the object of the
present invention is to provide an automotive climate control
system, in which the refrigerant which may leak out is prevented
from flowing into the cabin even in the case where the electric
equipment on board the vehicle is not supplied with power such as
when the ignition switch is in off state.
[0008] In order to achieve the above-mentioned object, according to
a first aspect of the invention, there is provided an automotive
climate control system comprising an air-conditioning casing (11)
which allows air to flow therethrough and to be blown out into the
cabin, a first heat exchanger (12) arranged in the air-conditioning
casing (11) for exchanging heat between the refrigerant and the
air, a face opening (17) arranged downstream of the first heat
exchanger (12) in the air flow for blowing out the air to the faces
of the occupants in the cabin, a foot opening (18) arranged
downstream of the first heat exchanger (12) in the air flow for
blowing out the air to the feet of the occupants in the cabin, a
defroster opening (19) arranged downstream of the first heat
exchanger (12) for blowing out the air to the vehicle windshield
glass, an internal air inlet (22) arranged upstream of the first
heat exchanger (12) in the air flow for introducing the air from
the cabin, and an external air inlet (23) arranged upstream of the
first heat exchanger (12) for introducing the air from outside the
cabin wherein, as long as the electrical equipment mounted on the
vehicle is not supplied with power, among a first air path (A)
leading from the first heat exchanger (12) to the face opening
(17), a second air path (B) leading from the first heat exchanger
(12) to the foot opening (18) and a third air path (C) leading from
the first heat exchanger (12) to the defroster opening (19), only
the air path (C) having a larger air resistance than an air path
(E) leading from the first heat exchanger (12) to the external air
inlet (23) passes the air therethrough while, at the same time, the
air passes through the air path (E) leading from the first heat
exchanger (12) to the external air inlet (23).
[0009] As a result, the refrigerant which may leak out from the
first heat exchanger (12) can be passed to the external air inlet
(23). Thus, the refrigerant that may leak from the first heat
exchanger (12) while the ignition switch is in off state can be
prevented by simple means from flowing into the cabin without any
leakage protection device such as a sensor.
[0010] According to a second aspect of the invention, there is
provided an automotive climate control system comprising an
air-conditioning casing (11) which allows air to flow therethrough
and to be blown into the cabin, a first heat exchanger (12)
arranged in the air-conditioning casing (11) for exchanging heat
between the refrigerant and the air, a face opening (17) arranged
downstream of the first heat exchanger (12) in the air flow for
blowing out the air to the faces of the occupants in the cabin, a
foot opening (18) arranged downstream of the first heat exchanger
(12) in the air flow for blowing out the air to the feet of the
occupants in the cabin, a defroster opening (19) arranged
downstream of the first heat exchanger (12) for blowing out the air
to the vehicle windshield glass, an internal air inlet (22)
arranged upstream of the first heat exchanger (12) in the air flow
for introducing the air from the cabin, and an external air inlet
(23) arranged upstream of the first heat exchanger (12) for
introducing the air from outside the cabin wherein, as long as the
electrical equipment on board the vehicle is not supplied with
power, among a first air path (A) leading from the first heat
exchanger (12) to the face opening (17), a second air path (B)
leading from the first heat exchanger (12) to the foot opening
(18), a third air path (C) leading from the first heat exchanger
(12) to the defroster opening (19), only the air path (C) having
the largest air resistance passes the air while, at the same time,
the air passes through the air path (E) leading from the first heat
exchanger (12) to the external air inlet (23).
[0011] As a result, as in the first aspect of the invention, the
refrigerant that has leaked out can be prevented from flowing into
the cabin with simple means without any protective device such as a
sensor.
[0012] According to a third aspect of the invention, there is
provided an automotive climate control system comprising an
air-conditioning casing (11) which allows the air to flow
therethrough and to be blown into the cabin, a first heat exchanger
(12) arranged in the air-conditioning casing (11) for exchanging
heat between the refrigerant and the air, a face opening (17)
arranged downstream of the first heat exchanger (12) in the air
flow for blowing our the air to the faces of the occupants in the
cabin, a foot opening (18) arranged downstream of the first heat
exchanger (12) in the air flow for blowing out the air to the feet
of the occupants in the cabin, a defroster opening (19) arranged
downstream of the first heat exchanger (12) for blowing out the air
to the vehicle windshield glass, an internal air inlet (22)
arranged upstream of the first heat exchanger (12) in the air flow
for introducing the air from the cabin, and an external air inlet
(23) arranged upstream of the first heat exchanger (12) for
introducing the air from outside the cabin wherein, as long as the
electrical equipment on board the vehicle is not supplied with
power, the air path (C) leading from the first heat exchanger (12)
to the defroster opening (19) passes air while at the same time
passing the air through the air path (E) leading from the first
heat exchanger (12) to the external air inlet (23).
[0013] As a result, as in the first embodiment of the invention,
the refrigerant that has leaked out can be prevented from flowing
into the cabin by simple means without providing any protective
device such as a sensor.
[0014] According to a sixth aspect of the invention, there is
provided an automotive climate control system wherein a second heat
exchanger (13) for heating the air is arranged between the first
heat exchanger (12) and the three openings (17 to 19) in the
air-conditioning casing (11), and as long as the electrical
equipment mounted on the vehicle is not supplied with power, the
air flowing from the first heat exchanger (12) toward the second
heat exchanger (13) passes in its entirety through the second heat
exchanger (13).
[0015] As a result, the air resistance in the air path in the
openings (17 to 19) can be further increased, so that the
refrigerant that has leaked out from the first heat exchanger (12)
can be positively passed to the external air inlet (23). Thus, the
refrigerant can be prevented without fail from flowing into the
cabin.
[0016] According to a seventh aspect of the invention, there is
provided an automotive climate control system, comprising an
air-conditioning casing (11) having arranged therein a second heat
exchanger (13) between a first heat exchanger (12) and three
openings (17 to 19) for heating the air, a bypass (14) for causing
the air passing from the first heat exchanger (12) toward the
second heat exchanger (13) to bypass the second heat exchanger (13)
and a bypass amount regulation means (15) for regulating the air
passage in the bypass (14), wherein the bypass amount regulation
means (15) closes the bypass (14) as long as the electrical
equipment mounted on the vehicle is not supplied with power.
[0017] As a result, the air resistance in the air path in the
openings (17 to 19) can be further increased, so that the
refrigerant that has leaked out from the first heat exchanger (12)
can be positively made to flow to the external air inlet (23). Thus
the refrigerant can be prevented without fail from flowing into the
cabin.
[0018] According to an eighth aspect of the invention, there is
provided an automotive climate control system, wherein a fluid
having a higher density than air is used as a refrigerant, and the
external air inlet (23) is arranged at a position lower than the
defroster opening (19).
[0019] As a result, the refrigerant heavier than air which may leak
out little by little from the first heat exchanger (12) when the
ignition switch is in off state, for example, can be discharged out
of the cabin from the external air inlet (23) earlier than from the
openings (17 to 19) inside the cabin, and therefore the refrigerant
can be prevented from flowing into the cabin more positively.
[0020] The present invention may be more fully understood from the
description of preferred embodiments of the invention set forth
below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a diagram schematically showing an automotive
climate control system according to an embodiment of the present
invention.
[0022] FIG. 2 is a diagram schematically showing the flow of the
refrigerant which may leak out from an automotive climate control
system according to an embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] FIG. 1 is a diagram schematically showing an automotive
climate control system according to an embodiment of the present
invention. Reference numeral 10 designates an air-conditioning unit
for harmonizing the air blown out into the cabin, and numeral 20 a
fan unit for blowing the air into the air-conditioning unit 10.
[0024] Numeral 11 designates an air-conditioning casing for passing
the air to be blown out into the cabin. The air-conditioning casing
11 has arranged therein an evaporator (first heat exchanger) 12 for
cooling the air flowing in the air-conditioning casing 11 and a
heater core (second heat exchanger) 13 arranged downstream of the
evaporator 12 in the air path for heating the air.
[0025] The evaporator 12 is a heat exchanger on the low pressure
side of a vapor compression refrigeration cycle in which the
refrigeration performance is exhibited by compressing and reducing
the pressure of a refrigerant and then evaporating the refrigerant
reduced in pressure. The heater core 13 is for heating the air with
the cooling water for the running engine (not shown) as a heat
source.
[0026] This embodiment employs a vapor compression refrigeration
cycle using carbon dioxide as a refrigerant. In the vapor
compression refrigeration cycle, a supercritical state occurs in
which the refrigerant pressure on high pressure side is not lower
than the critical pressure of the refrigerant.
[0027] The air-conditioning casing 11 also has arranged therein a
bypass 14 for causing the air flowing from the evaporator 12 toward
the heater core 13 (downstream) to bypass the heater core 13 and
flow downstream. Numeral 15 designates an air mix door (bypass
amount regulation means) for regulating the air flow in the bypass
14.
[0028] According to this embodiment, the flow rate of the cool air
cooled by the evaporator 12 and the flow rate of the warm air
heated by being passed through the heater core 14 are regulated by
adjusting the opening degree (air flow) of the air mix door 15,
thereby regulating the temperature of the air blown out into the
cabin.
[0029] Also, an air mix chamber (air mix space) 16 for mixing the
warm air and the cool air is arranged downstream of the heater core
13 and the air mix door 15 in the air flow. The air mix chamber 16
has arranged therein a face opening 17 for blowing out the air to
the faces of the occupants in the cabin, a foot opening 18 for
blowing out the air to the feet of the occupants in the cabin and a
defroster opening 19 for blowing out the air toward the vehicle
windshield glass W.
[0030] The openings 17 to 19 are opened/closed by first to third
blowout mode doors 17a to 19a. By opening/closing the blowout mode
doors 17a to 19a, the face mode in which air is blown out from the
face opening 17, the foot mode in which air is blown out from the
foot opening 18 and the defrost mode in which air is blown out from
the defroster opening 19 are switched with each other.
[0031] The defroster opening 19 has a plurality of narrow points
and turning points, and communicates with the air mix chamber 16
through a defroster duct 19a having a comparatively long path. In
defrost mode, therefore, the air resistance increases to a maximum
and decreases in foot mode and face mode in that order.
[0032] The air resistance in face mode is defined as the pressure
loss in the first air path A leading from a blowout air temperature
regulation section including the evaporator 12, the heater core 13
and the air mix door 15 to the face opening 17. The air resistance
in foot mode is defined as the pressure loss in the second air path
B leading from the blowout air temperature regulation section to
the foot opening 18. The air resistance in defrost mode is defined
as the pressure loss in the third air path C leading from the
blowout temperature regulation section to the defroster opening
19.
[0033] The fan unit 20 is arranged upstream of the air-conditioning
unit 10 in the air flow. The fan unit 20 includes a multiblade
centrifugal fan 21, an internal air inlet 22 located upstream of
the centrifugal fan 21 in the air flow for introducing the air from
the cabin into the air-conditioning casing 11 (fan unit 20), an
external air inlet 23 for introducing the air from outside the
cabin into the air-conditioning casing 11, and an internal/external
air switching door 24 for opening/closing the two inlets 22,
23.
[0034] The state in which the air is passed through the fourth air
path D from the internal air inlet 22 to the blowout air
temperature regulation unit by opening the internal air inlet 22 is
hereinafter called the internal air mode, while the state in which
the air is passed through the fifth air path E leading from the
external air inlet 23 to the blowout air temperature regulation
unit by opening the external air inlet 23 is hereinafter called the
external air mode.
[0035] Now, the operation features of the present embodiment will
be explained.
[0036] As long as the ignition switch (not shown) is off (the state
in which the electrical equipment including the ignition coil and
the fuel injection valve mounted on the vehicle are not supplied
with power), the blowout is set to defrost mode and the introduced
air is set to external mode regardless of the preceding state (the
state in which the ignition switch is on) of the blowout and the
introduced air.
[0037] As a result, in the case where the refrigerant leaks out
from the evaporator when the ignition switch is off, the
refrigerant that has thus leaked flows out toward the third air
path C and the fifth air path E as shown in FIG. 2. The third air
path C has a plurality of narrow points and turning points as
described above, and a comparatively long path with a large air
resistance. The fifth air path E, on the other hand, in which the
only device is the centrifugal fan 21, generally has a small air
resistance and has a comparatively large area. Most of the
refrigerant that has leaked out from the evaporator, therefore,
flows toward the fifth air path E having a small air resistance
(pressure loss).
[0038] Thus, even in the case where the refrigerant leaks out from
the evaporator when the ignition switch is off, the leaking
refrigerant can be prevented from flowing into the cabin by simple
means and without using a protective device such as a sensor.
[0039] Further, according to this embodiment, when the ignition
switch is off, the bypass 14 is closed up by the air mix door 15 so
that the air passing through the evaporator 12 is allowed to pass
through the heater core 13 in its entirety. In this way, the
pressure loss in the third air path C is further increased, and
thus the leaking refrigerant is positively prevented from flowing
into the cabin.
[0040] According to this embodiment, carbon dioxide larger in
density than the air is used as a refrigerant. In the case where
the evaporator 12 is mounted at a position lower than the defroster
opening 19 and the external air inlet 23 as in this embodiment,
therefore, the refrigerant that has leaked out little by little
expands upward and gradually come to stay in the air-conditioning
casing 11.
[0041] In view of this, according to this embodiment, the external
air inlet 23 is arranged at a position lower than the defroster
opening 19, so that the refrigerant in the air-conditioning casing
11 may flow out of the air-conditioning casing 11 (automotive
climate control system) by way of the external air inlet 23 earlier
than by way of the defroster opening 19.
[0042] Therefore, the refrigerant that has leaked out of the
evaporator 12 little by little when the ignition switch is off can
be prevented from overflowing the air-conditioning casing 11
(automotive climate control system) and flowing out into the
cabin.
[0043] Other embodiments will now be explained. Instead of carbon
dioxide used as a refrigerant in the aforementioned embodiment, a
combustible refrigerant such as propane or other materials such as
chlorofluoro hydrocarbon may be used as a refrigerant according to
another embodiment.
[0044] In the case where a material having a density smaller than
air is used as a refrigerant, the external air inlet 23 is not
necessarily arranged at a position lower than the defroster opening
19.
[0045] Also, unlike the automotive climate control system of an air
mix type according to the aforementioned embodiments in which the
temperature of the air blown out is regulated by regulating the
ratio between warm air and cool air by the air mix door 15, the
present invention is not limited to such a configuration. Instead,
an automotive climate control system of a reheat type is
applicable, in which all the air passing through the evaporator 12
is passed through the heater core 13, and the temperature of the
air blown out is regulated by regulating the degree to which the
air is heated in the heater core 13.
[0046] According to this invention, when the ignition switch is
off, the climate control system is set to external air mode while
at the same time setting the blowout to a mode with as large an air
resistance as possible to prevent the leaking refrigerant from
flowing into the cabin. In the case where the air resistance in
foot mode (second air path B) is larger than that in external air
mode (fifth air path E) according to the embodiments described
above, therefore, the climate control system may be set to external
air mode and foot mode at the same time when the ignition switch is
off.
[0047] Further, the air blowout is set to defrost mode in the
embodiments described above. According to still another embodiment,
however, the blowout may be set to a closed-up mode, if any, in the
climate control system.
[0048] Furthermore, instead of employing the heater core 13 as
means for heating the air as in the embodiments described above,
the air may be heated by carrying out the vapor compression
refrigeration cycle with a heat pump. In such a case, the
evaporator (first heat exchanger) 12 functions as a radiator.
[0049] In addition, the foregoing explanation refers to the case in
which the ignition switch is off as the state in which the
electrical equipment mounted in the vehicle is not supplied with
power. As an alternative, the state in which power is not supplied
to the electrical equipment mounted on the vehicle may be defined
as the one in which an accessory switch is off.
[0050] While the invention has been described by reference to
specific embodiments chosen for purposes of illustration, it should
be apparent that numerous modifications could be made thereto by
those skilled in the art without departing from the basic concept
and scope of the invention.
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