U.S. patent application number 11/667836 was filed with the patent office on 2008-02-28 for refrigerator.
Invention is credited to Satoru Hasegawa.
Application Number | 20080047294 11/667836 |
Document ID | / |
Family ID | 36587665 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080047294 |
Kind Code |
A1 |
Hasegawa; Satoru |
February 28, 2008 |
Refrigerator
Abstract
A refrigerator (1) having a temperature switchable compartment
(3) whose interior temperature can be switched among more than one
alternatives is provided with: a cooling device (17) for producing
cold air; a blower (14) for sending out the cold air produced by
the cooling device (17) into the temperature switchable compartment
(3); a temperature switchable compartment discharge damper (13) for
opening and closing an air introduction path (12) through which the
cooling device (17) communicates with the blower (14); and a
temperature switchable compartment return damper (20) for opening
and closing an air return path (19) through which an outlet port
(33b), from which air in the temperature switchable compartment (3)
flows out, communicates with the cooling device (17) and opens and
closes a communication path (36) through which the outlet port
(33b) communicates with the inlet side of the blower (14). When the
communication path (36) is closed and the air return path (19) is
opened by the temperature switchable compartment return damper (20)
and the blower (14) is driven after the temperature switchable
compartment discharge damper (13) is opened, cold air is introduced
into the temperature switchable compartment (3). When the
communication path (36) is opened and the air return path (19) is
closed by the temperature switchable compartment return damper (20)
and the blower (14) is activated after the temperature switchable
compartment discharge damper (13) is closed, the air in the
temperature switchable compartment (3) is circulated. In the
temperature switchable compartment discharge damper (13), a baffle
(42) is arranged closer to the cooling device (17) than an opening
(40a) is, so that the baffle (42) is swingable even if moisture
condensation occurs on the baffle (42) and the condensed water
freezes.
Inventors: |
Hasegawa; Satoru;
(Osaka-Shi, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
36587665 |
Appl. No.: |
11/667836 |
Filed: |
September 27, 2005 |
PCT Filed: |
September 27, 2005 |
PCT NO: |
PCT/JP05/17676 |
371 Date: |
May 16, 2007 |
Current U.S.
Class: |
62/412 ;
62/408 |
Current CPC
Class: |
F25D 31/005 20130101;
F25D 17/045 20130101; F25D 2700/121 20130101; F25D 2317/061
20130101; F25D 17/065 20130101; F25D 23/12 20130101; F25B 2400/01
20130101; F25D 2400/16 20130101 |
Class at
Publication: |
062/412 ;
062/408 |
International
Class: |
F25D 17/00 20060101
F25D017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 15, 2004 |
JP |
2004-362714 |
Feb 7, 2005 |
JP |
2005-029900 |
Claims
1. A refrigerator including a temperature switchable compartment
whose interior temperature can be switched among more than one
alternatives, the refrigerator comprising: a cooling device for
producing cold air; a blower for sending the cold air produced by
the cooling device into the temperature switchable compartment; an
introduction gate for opening and closing an air introduction path
through which the cooling device communicates with the blower; a
return gate for opening and closing an air return path through
which the cooling device communicates with an outlet port through
which air flows out of the temperature switchable compartment; and
a circulation gate for opening and closing a communication path
through which a circulation port formed in the temperature
switchable compartment communicates with an inlet side of the
blower, wherein, when the introduction gate and the return gate are
opened, the circulation gate is closed, and when the circulation
gate is opened, the introduction gate and the return gate are
closed.
2. The refrigerator of claim 1, further comprising a heater for
raising the interior temperature of the temperature switchable
compartment, wherein with the heater operated, the interior
temperature of the temperature switchable compartment can be
switched to a hot setting for keeping cooked food warm.
3. The refrigerator of claim 2, wherein the heater is a
heat-radiating glass-tube heater arranged so as to face the
blower.
4. The refrigerator of claim 1, wherein a single temperature
switchable compartment return damper is shared to serve as both the
return gate and the circulation gate, a single opening is formed to
serve as both the outlet port and the circulation port so that the
return path and the communication path extending from the opening
branch off each other at the temperature switchable compartment
return damper, and the temperature switchable compartment return
damper has a double-sided baffle that swings between a position in
which the baffle closes the communication path and a position in
which the baffle closes the air return path.
5. The refrigerator of claim 4, wherein the double-sided baffle is
swingably supported by a pivot shaft extending horizontally along a
top end of the double-sided baffle.
6. The refrigerator of claim 1, wherein a single damper is shared
to serve as both the introduction gate and the circulation gate,
the air introduction path and the communication path join at the
damper so as to be led to the inlet side of the blower, and the
damper has a double-sided baffle that swings between a position in
which the baffle interrupts the communication path and a position
in which the baffle interrupts the air introduction path.
7. The refrigerator of claim 1, wherein a temperature switchable
compartment discharge damper has an opening that communicates with
the temperature switchable compartment and a movable baffle that is
arranged on a cooling device side of the opening so as to open and
close the opening.
8. The refrigerator of claim 7, wherein the baffle is swingably
supported by a pivot shaft extending horizontally along a top end
of the baffle.
9. The refrigerator of claim 7, wherein a heat insulator is
provided on a surface of the baffle.
10. The refrigerator of claim 7, wherein, at a rim of the opening,
at a side thereof opposite from the baffle, there is formed a step
lower than the opening or a slope slanting downward from the rim of
the opening.
11. A refrigerator in which cold air produced by a cooling device
is supplied to a storage compartment through a cold air path,
wherein a damper for varying an amount of cold air supplied to the
storage compartment is arranged in the cold air path, and the
damper includes an opening that communicates with the storage
compartment and a movable baffle that is arranged on a cooling
device side of the opening so as to open and close the opening.
12. The refrigerator of claim 11, wherein the storage compartment
is a temperature switchable compartment whose interior temperature
can be switched among more than one alternatives, and a cooling
compartment is provided that is arranged parallel with the storage
compartment so as to receive cold air through a path branching off
the cold air path.
13. The refrigerator of claim 12, further comprising a heater for
raising the interior temperature of the temperature switchable
compartment, wherein, with the heater operated, the interior
temperature of the temperature switchable compartment can be
switched to a hot setting for keeping cooked food warm.
14. The refrigerator of claim 11, wherein the baffle is swingably
supported by a pivot shaft extending horizontally along a top end
of the baffle.
15. The refrigerator of claim 11, wherein a heat insulator is
provided on a surface of the baffle.
16. The refrigerator of claim 11, wherein, at a rim of the opening,
at a side thereof opposite from the baffle, there is formed a step
lower than the opening or a slope slanting downward from the rim of
the opening.
Description
TECHNICAL FIELD
[0001] The present invention relates to a refrigerator having a
temperature switchable compartment whose interior temperature can
be switched to a desired one by the user. The present invention
also relates to a refrigerator including a damper for opening and
closing a cold air path, the damper being provided at the cold air
inlet side of a storage compartment.
BACKGROUND ART
[0002] Patent Publication 1 discloses a refrigerator provided with
a temperature switchable compartment in addition to a freezer
compartment and a cooling compartment. This refrigerator includes:
a damper device for opening and closing a cold air path through
which cold air is supplied to the temperature switchable
compartment; and a heater for raising the interior temperature of
the temperature switchable compartment. This makes it possible for
the user to switch the interior temperature of the temperature
switchable compartment, according to the purpose for which he/she
uses it, to a desired low temperature zone among, for example,
those intended for freezing, cooling, partial freezing, and
chilling. [0003] [Patent Publication 1] JP-A-H10-288440
DISCLOSURE OF THE INVENTION
[0003] Problems to be Solved by the Invention
[0004] One disadvantage with the conventional refrigerator
described above is that since the interior temperature of the
temperature switchable compartment is changed through the
adjustment, using a damper device, of the amount of cold air
flowing from a cooling device into the temperature switchable
compartment, if there is a large difference between the temperature
of the cold air flowing into the temperature switchable compartment
and the preset temperature, it is not possible to produce an even
temperature distribution. Another disadvantages is that when a
heater is energized in an airtight condition, the temperature
around the heater rises, making it impossible to produce an even
temperature distribution.
[0005] An object of the present invention is to provide a
refrigerator that can produce an even temperature distribution in a
temperature switchable compartment.
Means for Solving the Problem
[0006] To achieve the above object, according to one aspect of the
present invention, a refrigerator including a temperature
switchable compartment, whose interior temperature can be switched
among more than one alternatives, is provided with: a cooling
device for producing cold air; a blower for sending the cold air
produced by the cooling device into the temperature switchable
compartment; an introduction gate for opening and closing an air
introduction path through which the cooling device communicates
with the blower; a return gate for opening and closing an air
return path through which the cooling device communicates with an
outlet port through which air flows out of the temperature
switchable compartment; and a circulation gate for opening and
closing a communication path through which a circulation port
formed in the temperature switchable compartment communicates with
an inlet side of the blower. Here, when the introduction gate and
the return gate are opened, the circulation gate is closed, and
when the circulation gate is opened, the introduction gate and the
return gate are closed.
[0007] With this structure, when the blower is operated with the
circulation gate closed and the introduction gate and the return
gate open, the cold air produced by the cooling device is sent into
the temperature switchable compartment through the air introduction
path. The cold air flows through the temperature switchable
compartment, through the outlet port, and flows back to the cooling
device through the air return path. The temperature switchable
compartment is cooled in this way, and by varying the degrees to
which the introduction gate and the return gate are opened or the
amount of air supplied from the blower, the interior temperature of
the temperature switchable compartment can be switched to different
internal temperatures such as a freezing, a partial freezing, a
chilling, and a cooling temperature. On the other hand, when the
blower is operated with the circulation gate open and with the
introduction gate and the return gate closed, the air inside the
temperature switchable compartment is led out thereof via the
circulation port through the communication path to the inlet side
of the blower, and is then sent into the temperature switchable
compartment. Thus, the air inside the temperature switchable
compartment is circulated.
[0008] According to the present invention, in the refrigerator
structured as described above, a heater may be provided for raising
the interior temperature of the temperature switchable compartment
so as to switch it to the hot setting for keeping cooked food warm.
With this structure, when the setting for the temperature
switchable compartment is switched to the hot setting, the
circulation gate is opened, and the introduction gate and the
return gate are closed. Then, the blower and the heater are
operated so as to raise the interior temperature of the temperature
switchable compartment. This makes temporary storage of cooked
food, warm storage of food for cooking purposes in winter, and the
like possible.
[0009] According to the present invention, the heater provided in
the refrigerator structured as described above may be a
heat-radiating glass-tube heater arranged so as to face the
blower.
[0010] Accorcing to the present invention, in the refrigerator
structured as described above, a single temperature switchable
compartment return damper may be shared to serve as both the return
gate and the circulation gate; a single opening may be formed to
serve as both the outlet port and the circulation port so that the
return path and the communication path extending from the opening
branch off each other at the temperature switchable compartment
damper; and the temperature switchable compartment return damper
may have a double-sided baffle that swings between a position in
which the baffle interrupts the communication path and a position
in which the baffle interrupts the air return path.
[0011] With this structure, the temperature switchable compartment
return damper having the swingable double-sided baffle is shared to
serve as both the return gate and the circulation gate, and when
the double-sided baffle closes the air return path, the
communication path is opened. In this state, when the blower is
operated with the temperature switchable compartment discharge
damper closed, the air inside the temperature switchable
compartment is led out thereof via the opening through the
communication path to the inlet side of the blower, and thus the
air is circulated. When the communication path is closed by the
double-sided baffle, the air return path is opened. In this state,
when the blower is operated with the temperature switchable
compartment discharge damper open, the cold air produced by the
cooling device flows into the temperature switchable compartment
through the air introduction path, through the opening, and then
back to the cooling device through the air return path.
[0012] According to the present invention, in the refrigerator
structured as described above, the double-sided baffle may be
swingably supported by a pivot shaft extending horizontally along a
top end of the double-sided baffle. With this structure, when the
double-sided baffle closes the air return path and condensation
occurs on the double-sided baffle due to a temperature difference
between the temperature switchable compartment side and the cooling
device side, the condensed water runs down, away from the
horizontally extending pivot shaft.
[0013] According to the present invention, a single damper may be
shared to serve as both the introduction gate and the circulation
gate; the air introduction path and the communication path may join
at the damper so as to be led to the inlet side of the blower; and
the damper may have a double-sided baffle that swings between a
position inn which the baffle closes the communication path and a
position in which the baffle closes the air introduction path.
[0014] With this structure, a single damper having a swingable
double-sided baffle is shared to serve as both the introduction
gate and the circulation gate, and when the air introduction path
is closed by the double-sided baffle, the communication path is
opened. In this state, when the blower is operated with the air
return gate closed, the air inside the temperature switchable
compartment is led out thereof via the opening through the
communication path, and to the inlet side of the blower, and thus
the air is circulated. When the communication path is closed by the
double-sided baffle, the air introduction path is opened. In this
state, when the blower is operated with the air return path open,
the cold air produced by the cooling device flows into the
temperature switchable compartment through the air introduction
path, through the opening, and back to the cooling device through
the air return path.
[0015] According to the present invention, in the refrigerator
structured as described above, the introduction gate may be a
temperature switchable compartment discharge damper, and the
temperature switchable compartment discharge damper may have an
opening that communicates with the temperature switchable
compartment and a movable baffle for opening and closing the
opening that is arranged on the cooling device side of the
opening.
[0016] With this structure, when the blower is operated with the
circulation gate closed and with the temperature switchable
compartment discharge damper and the return gate open, the cold air
produce by the cooling device is sent into the temperature
switchable compartment through the air introduction path. The cold
air flows through the temperature switchable compartment, through
the outlet port, and then back to the cooling device through the
air return path. In this way, the temperature switchable
compartment is cooled, and according to the degrees to which the
discharge damper of the temperature switchable compartment and the
return gate are opened or according to the amount of the air
supplied from the blower, the interior temperature of the
temperature switchable compartment can be switched among, for
example, those intended for freezing, partial freezing, chilling,
and cooling. When the blower is operated with the circulation gate
open and with the temperature switchable compartment discharge
damper and the return gate closed, the air inside the temperature
switchable compartment is led through the circulation port, via the
communication path, and to the inlet side of the blower, and is
then sent into the temperature switchable compartment. Thus, the
air inside the temperature switchable compartment is circulated.
The temperature-swtichable compartment discharge damper is disposed
in the air introduction path, and the temperature switchable
compartment communicates with the cooling device via the opening.
The opening is opened and closed by the movable baffle disposed on
the cooling device side of the opening.
[0017] According to the present invention, in the refrigerator
structured as described above, there may be provided a heater for
raising the interior temperature of the temperature switchable
compartment so that, by operating the heater, the interior
temperature of the temperature switchable compartment can be
switched to the hot setting for keeping cooked food warm. With this
structure, when the setting for the temperature switchable
compartment is switched to the hot setting, the circulation gate is
opened, and the temperature switchable compartment discharge damper
and the air return gate are closed. Then, the blower and the heater
are operated so as to raise the interior temperature of the
temperature switchable compartment. This allows temporary storage
of cooked food, warm storage of food for cooking purposes in
winter, and the like.
[0018] According to another aspect of the present invention, in a
refrigerator in which the cold air produced by a cooling device is
supplied to a storage compartment through a cold air path, a damper
for varying the amount of cold air supplied to the storage
compartment is disposed in the cold air path; and the damper has an
opening that communicates with the storage compartment and a
movable baffle that opens and closes the opening and that is
arranged on the cooling device side of the opening. With this
structure, the cold air produced by the cooling device is supplied
to the storage compartment through the cold air path, and thus the
storage compartment is cooled. The damper is disposed in the cold
air path, and the storage compartment communicates with the cooling
device via the opening. The opening is opened and closed by the
movable baffle arranged on the cooling device side of the
opening.
[0019] According to the present invention, in the refrigerator
structured as described above, the storage compartment may be a
temperature switchable compartment whose interior temperature can
be switched among more than one alternatives; and there may be
provided a cooling compartment that is arranged in parallel with
the storage compartment and to which cold air is supplied through a
path that branches off the cold air path.
[0020] According to the present invention, in the refrigerator
structured as described above, the baffle may be supported by a
pivot shaft horizontally extending along the top end of the baffle.
With this structure, when a path through which cold air is supplied
to a storage compartment such as a temperature switchable
compartment is closed by the baffle and a temperature difference
arises between the storage compartment side and the cooling device
side, causing condensation on the baffle, the condensed water runs
down, away from the horizontally extending pivot shaft.
[0021] According to the present invention, in the refrigerator
structured as described above, a heat insulator may be provided on
a surface of the baffle.
[0022] According to the present invention, in the refrigerator
structured as described above, at a rim of the opening, at a side
thereof opposite from the baffle, there may be formed a step lower
than the opening or a slope slanting downward from the rim of the
opening. With this structure, when condensation occurs on the side
of the baffle opposite from the cooling device side, the condensed
water runs down the baffle and is led to the storage compartment
(e.g., a temperature switchable compartment) side via the step or
the slope.
ADVANTAGES OF THE INVENTION
[0023] According to the present invention, a refrigerator is
provided with a blower for sending cold air, an introduction gate
for opening and closing an air introduction path, a return gate for
opening and closing an air return path, and a circulation gate for
opening and closing a communication path through which a
circulation port formed in a temperature switchable compartment
communicates with the inlet side of the blower. Here, when the
circulation gate is opened, the introduction gate and the return
gate are closed, and this allows the air inside the temperature
switchable compartment in an airtight state to be circulated
therein, making it possible to produce an even temperature
distribution inside the temperature switchable compartment. The
circulation gate is closed when the introduction gate and the
return gate are opened, and hence the cold air flows through the
temperature switchable compartment, and this makes it possible to
produce an even temperature distribution inside the temperature
switchable compartment. At this time, since the circulation gate is
closed, it is possible to prevent the efficiency of the blower from
decreasing.
[0024] According to the present invention, a heater is provided for
raising the interior temperature of the temperature switchable
compartment and the interior temperature of the temperature
switchable compartment can be switched to the hot setting for
keeping heated food hot by operating the heater, and hence, it is
possible to provide a refrigerator that is economical to the user
by eliminating the need for a separate warm-keeping box or the like
for keeping cooked food warm and that is useful by eliminating the
need for securing a space for such a warm-keeping box or the like.
It is also possible to prevent the heater and the components around
it from deforming, burning, or smoking.
[0025] According to the present invention, the heater is a
heat-radiating glass-tube heater having a high heating rate
arranged so as to face the blower, and this allows the interior
temperature of the temperature switchable compartment to quickly
pass through the temperature range in which food poisoning
microorganisms grow. Therefore, it is possible to provide a
refrigerator which is safe in terms of food hygiene. Furthermore,
even a high-capacity heat-radiating glass-tube heater occupies a
small space, and hence the heater can be disposed in a rear portion
of the temperature switchable compartment, and this reduces the
risk of the user getting burned. Moreover, the surface temperature
of the heater can be lowered, thereby improving the safety.
[0026] According to the present invention, a single temperature
switchable compartment return damper is shared to serve as both the
return gate and the circulation gate, and a swingable double-sided
baffle selectively closes one of the communication path and the air
return path at a time, and this reduces the cost of the
refrigerator and improves the volume efficiency thereof.
[0027] According to the present invention, the double-sided baffle
is supported by a pivot shaft horizontally extending along the top
end of the double-sided baffle, and hence, when a temperature
difference arises between the storage compartment side and the
cooling device side of the double-sided baffle, causing
condensation on the double-sided baffle, the condensed water runs
down, away from the pivot shaft. This prevents the pivot shaft from
being frozen up even if the condensed water freezes when the
opening is opened, permitting the double-sided baffle to move
normally. This also helps prevent the swinging movement of the
double-sided baffle from being hampered by the condensed water that
has dripped down from the double-sided baffle to freeze in a
heap.
[0028] According to the present invention, a single damper is
shared to serve as both the introduction gate and the circulation
gate, and the swingable double-sided baffle selectively closes one
of the communication path and the air return path at a time. This
reduces the cost of the refrigerator and improves the volume
efficiency thereof.
[0029] According to the present invention, in the temperature
switchable compartment discharge damper disposed in the air
introduction path, a baffle for opening and closing the opening is
located on the cooling device side of the opening, and thus, when
the baffle closes the opening, only the portion thereof showing
through the rim of the opening is exposed to the temperature
switchable compartment side, whose temperature is higher than that
of the cooling device side. Hence, when a temperature difference
exists between the cooling device side and the temperature
switchable compartment side, condensation occurs only on the
portion of the baffle showing through the rim of the opening but
not on the pivot shaft of the baffle or other portions thereof.
Therefore, even when the opening is opened and the condensed water
meets the cold air to freeze, the normal movement of the baffle is
not hampered, and thus undercooling and overcooling of the
temperature switchable compartment can be prevented.
[0030] According to the present invention, since, in the damper
disposed in the cold air path, the baffle for opening and closing
the opening is disposed on the cooling device side of the opening,
when the baffle closes the opening, only the portion of the baffle
showing through the rim of the opening is exposed to the storage
compartment side, whose temperature is higher than that of the
cooling device side. Hence, when a temperature difference exists
between the cooling device side and the storage compartment side,
condensation occurs only on the portion of the baffle showing
through the rim of the opening but not on the pivot shaft of the
baffle or other portions thereof. Therefore, when the opening is
opened and the condensed water meets cold air to freeze, the normal
movement of the baffle is not hampered, and thus undercooling and
overcooling of the storage compartment can be prevented.
[0031] According to the present invention, the baffle is supported
by a pivot shaft horizontally extending along the top end of the
baffle. Thus, when a temperature difference arises between the
temperature switchable compartment side and the cooling device side
of the baffle and condensation occurs on the baffle, the condensed
water runs down, away from the pivot shaft. Hence, even when the
opening is opened and the condensed water meets cold air to freeze,
it is possible to prevent the pivot shaft from being frozen up, and
thereby to permit the baffle to move normally. It is also possible
to prevent the swinging movement of the baffle from being hampered
by the freezing of the condensed water that has dripped from the
baffle.
[0032] According to the present invention, a heat insulator is
provided on a surface of the baffle, and this reduces condensation
on the baffle.
[0033] According to the present invention, around the rim of the
opening at the side of the opening opposite from the baffle, there
is formed a step lower than the opening or a slope slanting
downward from the rim of the opening. Hence, when condensation
occurs on the baffle and the condensed water runs down, the
condensed water is led from the rim of the opening down to the step
or along the slope to the side opposite from the cooling device.
Therefore, it is possible to prevent the condensed water from
entering the cooling device side via the opening when the baffle is
opened.
[0034] According to the present invention, the storage compartment
is a temperature switchable compartment whose interior temperature
can be switched among more than one alternatives, and there is
provided a cooling compartment that is arranged in parallel with
the storage compartment and to which cold air is supplied through a
path branching off the cold air path. Hence, it is possible to
store articles in the cooling compartment either in cold storage or
in frozen storage, while producing an even temperature distribution
inside the temperature switchable compartment by keeping it
airtight and circulating air therein.
BRIEF DESCRIPTION OF DRAWINGS
[0035] [FIG. 1] A front view of a refrigerator embodying the
present invention;
[0036] [FIG. 2] A right side view of the refrigerator embodying the
present invention;
[0037] [FIG. 3] A vertical sectional view as seen from the right
side of the refrigerator embodying the present invention;
[0038] [FIG. 4] A vertical sectional view as seen from the right
side of a temperature switchable compartment of the refrigerator
embodying the present invention;
[0039] [FIG. 5] A vertical sectional view as seen from the right
side of the temperature switchable compartment of the refrigerator
embodying the present invention;
[0040] [FIG. 6] A vertical sectional view as seen from the front of
a middle portion of the refrigerator embodying the present
invention;
[0041] [FIG. 7] A cold air circuit diagram showing how cold air
flows in the refrigerator embodying the present invention;
[0042] [FIG. 8] Diagrams showing a discharge damper of the
temperature switchable compartment in the refrigerator embodying
the present invention;
[0043] [FIG. 9] A vertical sectional view as seen from the side
showing how the discharge damper of the temperature switchable
compartment is fitted in the refrigerator embodying the present
invention;
[0044] [FIG. 10] A diagram illustrating, by way of a
counterexample, the effect of the discharge damper of the
temperature switchable compartment of the refrigerator embodying
the present invention; and
[0045] [FIG. 11] A diagram illustrating, by way of a
counterexample, the effect of the discharge damper of the
temperature switchable compartment of the refrigerator embodying
the present invention.
LIST OF REFERENCE SYMBOLS
[0046] 1 refrigerator [0047] 2 cooling compartment [0048] 3
temperature switchable compartment [0049] 4 ice-maker compartment
[0050] 5 vegetable compartment [0051] 6 freezer compartment [0052]
9 door [0053] 12 air introduction path [0054] 13 temperature
switchable compartment discharge damper [0055] 14, 18, 28 blower
[0056] 15 heater [0057] 17 evaporator [0058] 16, 24 temperature
sensor [0059] 19, 21 air return path [0060] 20 temperature
switchable compartment return damper [0061] 22 freezer compartment
damper [0062] 25 chilling compartment damper [0063] 30 thermal fuse
[0064] 31, 32 cold air path [0065] 33 rear panel [0066] 33a inlet
port [0067] 33b outlet port [0068] 35 compressor [0069] 36
communication path [0070] 40 housing [0071] 40a opening [0072] 42
baffle [0073] 42a pivot shaft [0074] 43 sealing member
BEST MODE FOR CARRYING OUT THE INVENTION
[0075] Hereinafter, embodiments of the present invention will be
described with reference to the accompanying drawings. FIGS. 1 and
2 are a front view and a right side view, respectively, of a
refrigerator embodying the present invention. A cooling compartment
2 is arranged in a top portion of the refrigerator 1, and a
temperature switchable compartment 3 and an ice-maker compartment 4
are arranged in a middle portion thereof. In a bottom portion of
the refrigerator 1, a vegetable compartment 5 and a freezer
compartment 6 are arranged.
[0076] The cooling compartment 2 has double doors and keeps
articles in cold storage. The temperature switchable compartment 3
is arranged in a left side of the middle portion of the
refrigerator 1 and the interior temperature of the temperature
switchable compartment 3 can be switched by the user. The ice-maker
compartment 4 is arranged in a right side of the middle portion of
the refrigerator 1 and makes ice. The vegetable compartment 5 is
arranged in a left side of the bottom portion of the refrigerator 1
and the interior temperature thereof is maintained at a temperature
suitable for storing vegetables (e.g., 8.degree. C.). The freezer
compartment 6 is arranged in a right side of the bottom portion of
the refrigerator 1; it communicates with the ice-maker compartment
4, and keeps articles in frozen storage.
[0077] FIG. 3 is a vertical sectional view, as seen from the right
side, of the refrigerator 1. The freezer compartment 6 and the
ice-maker compartment 4 are each provided with a storage case 11.
Likewise, the vegetable compartment 5 and the temperature
switchable compartment 3 are each provided with a storage case 11.
The cooling compartment 2 includes a plurality of storage shelves
41 on which to place stored articles. The doors of the cooling
compartment 2 have storage pockets 42. These make the refrigerator
1 handy to use. Inside the cooling compartment 2, in a bottom part
thereof, a chilling compartment 23 is arranged, and the interior
temperature is maintained within a chilling temperature zone (about
-3.degree. C.).
[0078] Behind the freezer compartment 6, a cold air path 31 is
formed. In the cold air path 31, there is arranged an evaporator
17, which is connected to a compressor 35. Behind the cooling
compartment 2, there is formed a cold air path 32 that communicates
with the cold air path 31. When the compressor 35, to which a
condenser and an expander (neither is illustrated) are connected,
is operated, it circulates a refrigerant such as isobutane through
a refrigeration cycle and thereby achieves heat exchange with the
evaporator 17, which is disposed at the cold end of the
refrigeration cycle, where cold air is produced. Thus, the
compressor 35 and the evaporator 17, together with the condenser
and the expander, constitute a cooling device for producing cold
air.
[0079] In the cold air paths 31 and 32, blowers 18 and 28 are
arranged, respectively. As will be described in detail later, when
the blower 18 is operated, the cold air produced at the evaporator
17 is supplied through the cold air path 31 to the freezer
compartment 6, the ice-maker compartment 4, the chilling
compartment 23, and the temperature switchable compartment 3.
Moreover, when the blower 28 is operated, the cold air is also
supplied through the cold air path 32 to the cooling compartment 2
and the vegetable compartment 5.
[0080] FIG. 4 is a vertical sectional view, as seen from the right
side, of the temperature switchable compartment 3. The temperature
switchable compartment 3 is, at the top and bottom faces thereof,
separated from the cooling compartment 2 and the vegetable
compartment 5 by partition walls 7 and 8, respectively. The
temperature switchable compartment 3 can be opened and closed at
the front face thereof with a pivoted door 9. The rear face of the
temperature switchable compartment is covered with a rear panel 33.
Inside the temperature switchable compartment, a drawer-type
storage case 11 is provided.
[0081] Behind the rear panel 33, between it and a heat insulating
wall 10, which constitutes an exterior wall of the refrigerator 1,
an air introduction path 12 is formed. Through the air introduction
path 12, an inflow port 33a formed in the rear panel 33 connects to
the cold air path 31 (see FIG. 3). In the air introduction path 12,
a temperature switchable compartment discharge damper 13
(introduction gate) is provided. When the temperature switchable
compartment discharge damper 13 is opened, the cold air produced at
the evaporator 17 (see FIG. 3) is led to the temperature switchable
compartment 3.
[0082] FIGS. 8A to 8C are a front view, a top view, and a vertical
sectional side view, respectively, of the temperature switchable
compartment discharge damper 13. The temperature switchable
compartment discharge damper 13 has a baffle 42 provided inside a
resin-molded housing 40 having an opening 40a formed in the front
face thereof. The baffle 42 is swingably supported on a pivot shaft
42a extending horizontally along the top end thereof inside the
housing 40.
[0083] When a drive motor 41 coupled to the pivot shaft 42a is
driven, the baffle 42 swings as indicated by arrow H. As the baffle
42 swings, it opens and closes the opening 40a, and thereby opens
and closes the temperature switchable compartment discharge damper
13. On the baffle 42, on the side thereof facing the opening 40a,
there is disposed a sealing member 43 that is formed of a heat
insulating material and comes into close contact with the rim of
the opening 40a.
[0084] FIG. 9 is a vertical sectional view, as seen from the side,
showing how the temperature switchable compartment discharge damper
13 is fitted. The temperature switchable compartment discharge
damper 13 is fitted to a wall 50 of the air introduction path 12.
As will be described later, the air introduction path 12 branches
in two directions, specifically on one hand in the direction of the
temperature switchable compartment 3, which is arranged further
leftward of the figure, and on the other hand, in the direction of
the chilling compartment 23, which is arranged further upward of
the figure. The air introduction path 12 communicates with the
temperature switchable compartment 3 via a hole 50a. The
temperature switchable compartment discharge damper 13 is arranged
with the opening 40a located on the temperature switchable
compartment 3 side of the baffle 42, and with the baffle 42 located
on the evaporator 17 side of the opening 40a (relative to FIG. 9,
the temperature switchable compartment 3 is situated further
leftward and the evaporator 17 is situated further rightward).
[0085] Since the temperature of the cold air flowing through the
air introduction path 12 is lower than the interior temperature of
the temperature switchable compartment 3, when the baffle 42 closes
the opening 40a, a temperature difference arises between opposite
sides of the baffle 42. If, as shown in FIG. 10, the baffle 42 is
located on the temperature switchable compartment 3 side of the
opening 40a (i.e., left in the figure), the baffle 42 becomes
hotter except in the portion thereof that shows through the opening
40a.
[0086] This causes condensation on the warmer portion of the baffle
42, and, if it happens, when the opening 40a is opened, the
condensed water meets cold air and freezes, freezing up the pivot
shaft 42a. If, as a result, the baffle 42 becomes unable to fully
open the opening 40a, the interior temperature of the temperature
switchable compartment 3 is undercooled; if the baffle 42 becomes
unable to fully close the opening 40a, the temperature switchable
compartment 3 is overcooled.
[0087] In contrast, in the present embodiment, the baffle 42 is
located on the evaporator 17 side of the opening 40a; hence, when
the opening 40a is closed, the baffle 42 becomes hotter only in the
portion thereof showing through the opening 40a. In addition, the
sealing member 43 formed of a heat insulating material disposed on
the surface of the baffle 42 prevents condensation. The heat
insulator may be disposed on the face of the baffle 42 opposite
from the opening 40a.
[0088] Even if condensation occurs on the baffle 42, it occurs only
on the portion thereof that shows through the opening 40a, and not
on the pivot shaft 42a of the baffle 42. Therefore, even if the
condensed water freezes when the opening 40a is opened, the baffle
42 swings normally, without causing undercooling or overcooling of
the temperature switchable compartment 3.
[0089] The baffle 42 is particularly prone to condensation of
moisture from stored articles when the internal temperature of the
temperature switchable compartment 3 is at the hot setting (for
example, 55.degree. C. to 80.degree. C.), which will be described
later. Even then, despite a large amount of frozen condensed water,
the baffle 42 swings normally, without causing undercooling or
overcooling of the temperature switchable compartment 3, and thus
with greater effect. Similar benefits can be obtained also in a
case where the baffle 42 is a sliding one instead of a swinging
one.
[0090] With a similar structure, similar benefits can be obtained
also in a case where a damper is arranged for opening and closing a
cold air path through which cold air is supplied to a storage
compartment whose cold air circuit is arranged in parallel with
that of another cooling compartment wherein when the damper is
closed, the air in the storage compartment is circulated inside it.
Specifically, by locating a baffle on the evaporator (cooling
device) side of an opening in the damper, it is possible to prevent
frozen condensed water from hampering the normal movement of the
baffle. Thus, it is possible to prevent undercooling and
overcooling of the storage compartment.
[0091] Since the pivot shaft 42a is arranged along the top end of
the baffle 42, even when condensation occurs on the baffle 42, the
condensed water runs down, away from the pivot shaft 42a. Hence,
even when the opening 40a is opened and the condensed water meets
cold air and freezes, the pivot shaft 42a is prevented more
effectively from being frozen up, so that the baffle 42 swings
normally.
[0092] If, as shown in FIG. 11, the pivot shaft of the baffle 42
extends vertically, when the opening 40a is opened, the condensed
water that has dripped from the baffle 42 freezes in a heap, and
this hampers the swinging movement of the baffle 42. By contrast,
in the present embodiment, where the pivot shaft 42a extends
horizontally along the top end of the baffle 42, when the opening
40a is opened, the bottom end of the baffle 42 retracts by moving
up. This makes it possible to prevent the swinging movement of the
baffle 42 from being hampered even when condensed water drips from
the baffle 42 and freezes.
[0093] Back in FIG. 9, the hole 50a in the wall 50 is formed to be
larger in diameter than the opening 40a, and a step 50b is formed
at a level lower than the opening 40a. Thus, the condensed water
that has run down the baffle 42 is diverted from the rim of the
opening 40a into the temperature switchable compartment 3. This
prevents entry of condensed water through the opening 40a into the
evaporator 17. Instead of the step 50b, a slope slanting downward
from the rim of the opening 40a may be formed.
[0094] In FIG. 4, a blower 14 is arranged between the temperature
switchable compartment discharge damper 13 and the inlet port 33a.
In a bottom portion of the rear panel 33, an outlet port 33b is
formed, and when the blower 14 is activated, cold air is easily
introduced from the cold air path 31 into the temperature
switchable compartment 3 via the inlet port 33a and then discharged
out of the temperature switchable compartment 3 via the outlet port
33b. The amount of air supplied from the air introduction path 12
to the temperature switchable compartment 3 is controlled by
opening and closing the temperature switchable compartment
discharge damper 13.
[0095] Behind the outlet port 33b, there is formed an air return
path 19 through which air returns to the air cooling device 17. In
the air return path 19, there is formed a temperature switchable
compartment return damper 20 (return gate) open to face the outlet
port 33b. In the rear and the top of the temperature switchable
compartment return damper 20, openings 20b and 20c are formed,
respectively, and inside the temperature switchable compartment
return damper 20, there is arranged a double-sided swingable baffle
20a for selectively closing one of the openings 20b and 20c at a
time.
[0096] When the opening 20c is closed and the opening 20b is open,
the air that has flowed out of the outlet port 33b flows into the
air return path 19. When the opening 20b is closed and the opening
20c is opened, as shown in FIG. 5, the air that has flowed out of
the outlet port 33b is led to the inlet side of the blower 14. In
this way, a communication path 36 is formed, through which the
outlet port 33b communicates with the inlet side of the blower 14
via the opening 20c of the temperature switchable compartment
return damper 20. Thus, with the blower 14 operated, the air in the
temperature switchable compartment 3 can be circulated inside it
via the communication path 36.
[0097] Since the pivot shaft of the baffle 20a extends horizontally
along the top end thereof, even when a temperature difference
arises between the evaporator 17 side and the temperature
switchable compartment 3 side of the baffle 20a and condensation
occurs on the baffle 20a, the condensed water runs down, away from
the pivot shaft. Hence, even when the condensed water freezes when
the opening 20b is opened, it is possible to prevent the pivot
shaft from being frozen up to ensure that the baffle 20a swings
normally. When the baffle 20a swings, the bottom end thereof
retracts by moving up. This prevents the swinging movement of the
double-sided baffle 20a from being hampered by condensed water that
has dripped therefrom and has frozen in a heap.
[0098] The temperature switchable compartment return damper 20
serves as a circulation gate for opening and closing the
circulation path that includes the communication path 36. The
outlet port 33b serves as a circulation port via which air flows
out of the temperature switchable compartment 3 into the
communication path 36. The communication path 36 may be formed by
arranging the circulation port at a position different from that of
the outlet port 33b. In this case, however, in addition to the
temperature switchable compartment return damper 20, another
circulation gate for opening and closing the communication path 36
needs to be formed. Hence, with the present embodiment, in which
the outlet port 33b is shared as the circulation port and the
temperature switchable compartment return damper 20 having the
double-sided baffle 20a serves as the circulation gate, it is
possible to reduce the cost of the refrigerator 1 and to improve
the volume efficiency thereof.
[0099] In a top rear portion of the rear panel 33, a heater 15 is
arranged. The heater 15 is a heat-radiating glass-tube heater, and
the heat therefrom is radiated through the rear panel 33 to heat
the temperature switchable compartment 3. The blower 14 is arranged
such that it sends air toward the surface of the heater 15. This
helps lower the surface temperature of the heater 15, and thereby
improves safety.
[0100] On the bottom rear portion of the rear panel 33, a
temperature sensor 16 is arranged. The temperature sensor 16
detects the interior temperature of the temperature switchable
compartment 3 and sends a detection signal to a controller (not
shown). The controller, according to the detection result of the
temperature sensor 16, controls the heater 15, the temperature
switchable compartment discharge damper 13, and the blower 14, so
that the interior temperature of the temperature switchable
compartment 3 is maintained at a preset temperature.
[0101] Above the heater 15, a temperature sensor 24 is arranged
adjacent to the heater 15. The temperature sensor 24 is firmly
attached on the ceiling face of the part of the rear panel 33 so
bent as to enclose the heater 15. Thus, the temperature closely
above the heater 15, where heating proceeds fastest with the rising
stream of air heated by the heat radiating from the heater 15, is
detected by the temperature sensor 24.
[0102] When the temperature sensor 24 finds the temperature in the
vicinity of the heater 15 to be abnormally high, the heater 15 is
de-energized. In this way, it is possible to prevent the heater 15
and the components around it from breaking, burning, or smoking.
Furthermore, above the temperature sensor 16, a thermal fuse 30 is
arranged. The thermal fuse 30, when the temperature thereof becomes
as high as a predetermined level, melts so that the heater 15 is
de-energized. This further improves safety.
[0103] FIG. 6 is a vertical sectional view, as seen from the front,
of the middle portion of the refrigerator 1. The cold air path 31
behind the freezer compartment 6 has an opening formed at upper
front of the blower 18, and the blower 18 sends air into the
ice-maker compartment 4. In a bottom portion of the freezer
compartment 6, which communicates with the ice-maker compartment 4,
there is arranged a freezer compartment damper 22. Behind the
freezer compartment 6, at the bottom thererof, there is arranged an
air return path 21 (see FIG. 3) that leads air through the freezer
compartment damper 22, to the evaporator 17, and then back to the
cold air path 31. The amount of air led out of the freezer
compartment 6 is controlled by opening and closing the freezer
compartment damper 22.
[0104] At the top thereof, the cold air path 31 communicates with
the cold air path 32 via the cooling compartment damper 27. The
cold air path 31 also branches into the air introduction path 12,
so as to communicate, on one hand, with the chilling room 23 via
the chilling compartment damper 25 and, on the other hand, with the
temperature switchable compartment 3 via the temperature switchable
compartment discharge damper 13 as described above.
[0105] In the cooling compartment 2, in a rear bottom portion
thereof, there is formed a cooling compartment outlet port (not
shown). In the vegetable compartment 5, a vegetable compartment
inlet port (not shown) is formed. The cooling compartment outlet
port and the vegetable compartment inlet port are coupled to each
other via a path (not shown) located behind the temperature
switchable compartment 3, and thereby the cooling compartment 2
communicates with the vegetable compartment 5.
[0106] The air return path 19 that communicates with the
temperature switchable compartment 3 extends downward from the
temperature switchable compartment return damper 20 to run behind
the temperature switchable compartment 3 and the vegetable
compartment 5. By opening and closing the temperature switchable
compartment return damper 20, the air in the temperature switchable
compartment 3 is led to the evaporator 17 through the air return
paths 19 and 21. In the rear face of the vegetable compartment 5,
there is formed a vegetable compartment outlet port (not shown)
that communicates with the air return path 19.
[0107] FIG. 7 is a cold air circuit diagram showing how cold air
flows in the refrigerator 1. When the blower 18 is operated, the
cold air produced at the evaporator 17 rises through the cold air
path 31 as indicated by arrow A (see FIG. 6), and is supplied to
the ice-maker compartment 4. The cold air supplied to the ice-maker
compartment 4 flows through the ice-maker compartment 4 and the
freezer compartment 6, and then flows out via the freezer
compartment damper 22 to return to the evaporator 17 through the
air return path 21. In this way, the ice-maker compartment 4 and
the freezer compartment 6 are cooled.
[0108] When the blower 28 is operated, part of the cold air
branches off the cold air path 31 at the top thereof to flow into
and through the cold air path 32 as indicated by arrow B (see FIG.
6) via the cooling compartment damper 27, and is sent to the
cooling compartment 2; that part of the cold air also flows into
and through the air introduction path 12 as indicated by arrow C
(see FIG. 6), and is then supplied to the chilling compartment 23.
The cold air sent into the cooling compartment 2 and the chilling
compartment 23 flows through them and then flows into the vegetable
compartment 5. The cold air that has flowed into the vegetable
compartment 5 flows therethrough and then flows through the air
return paths 19 and 21 back to the evaporator 17. In this way, the
cooling compartment 2 and the vegetable compartment 5 are cooled.
When the preset temperatures are obtained, the cooling compartment
damper 27 and the chilling compartment damper 25 are closed.
[0109] When the blower 14 is operated, part of the cold air
branches off the cold air path 31 at the top thereof to flow
through the air introduction path 12 into, as indicated by arrow D
(see FIGS. 4 and 6), the temperature switchable compartment 3 via
the temperature switchable compartment discharge damper 13. The
cold air that has flowed into the temperature switchable
compartment 3 flows therethrough, then flows out thereof through
the outlet port 33b, and then returns to the evaporator 17 through
the air return paths 19 and 21 as indicated by arrow E (see FIGS. 4
and 6). Thus, the inside of the temperature switchable compartment
3 is cooled.
[0110] As described above, the interior temperature of the
temperature switchable compartment 3 can be switched by the user as
he/she desires. For example, the user can select any temperature
zone from among those intended for freezing (-15.degree. C.),
partial freezing (-8.degree. C.), chilling (-3.degree. C.), cooling
(3.degree. C.), vegetable (8.degree. C.). This enables the user to
keep articles in frozen or cool storage at the desired temperature.
The switching of the interior temperature of the temperature
switchable compartment 3 can be achieved by changing the degree to
which the temperature switchable compartment discharge damper 13 is
opened or the amount of air supplied from the blower 14.
[0111] In that case, as shown in FIG. 4, the double-sided baffle
20a of the temperature switchable compartment return damper 20 is
so located that it keeps the air return path 19 open and the
communication path 36 closed. Hence, the cold air that flows in via
the inlet port 33a flows via the temperature switchable compartment
return damper 20 into the air return path 19, without circulating
through the communication path 36. This prevents the cold air from
being short-circuited through the communication path 36 and thereby
improves the efficiency of the blower 14.
[0112] When, for example, the interior temperature of the
temperature switchable compartment 3 is switched from the
"freezing" to the "cooling" zone, the temperature may be raised by
energizing the heater 15. This allows quick switching of the
interior temperature of the temperature switchable compartment 3 to
a desired one. Furthermore, by energizing the heater 15, the
interior temperature of the temperature switchable compartment 3
can be switched from the cold setting for frozen or cold storage of
articles to the hot setting for temporary storage of cooked food,
warm storage of food for cooking purposes, and the like.
[0113] When the interior temperature of the temperature switchable
compartment 3 is at the hot setting, as shown in FIG. 5, the
temperature switchable compartment discharge damper 13 is closed
and the double-sided baffle 20a of the temperature switchable
compartment return damper 20 is positioned such that it keeps the
air return path 19 closed and the communication path 36 open. When
the heater 15 and the blower 14 are operated, the air sent by the
blower 14 as indicated by arrow F flows through the communication
path 36 via the outlet port 33b as indicated by arrow G.
[0114] Thus, the air in the temperature switchable compartment 3 is
circulated by being led to the blower 14 via the temperature
switchable compartment return damper 20 as indicated by the dotted
line S in FIG. 7. This makes it possible to keep the temperature
switchable compartment 3 airtight and thereby to prevent the warm
air therein from escaping. Hence, it is possible to produce an even
temperature distribution inside the temperature switchable
compartment 3 at the hot setting and to prevent the heater 15 and
the components around it from deforming, burning, or smoking.
Moreover, it is possible to realize a refrigerator that is
economical to the user by eliminating the need for a separate
warm-keeping box or the like for keeping cooked food warm and that
is useful by eliminating the need for securing a space for such a
warm-keeping box or the like.
[0115] It is preferable that the interior temperature of the
temperature switchable compartment 3 at the hot setting be kept at
50.degree. C. or more. This is in consideration of the fact that
common microorganisms causing food poisoning grow at 30.degree. C.
to 45.degree. C., and also in consideration of the permitted
tolerance in the heater capacity, the temperature distribution
inside the temperature switchable compartment 3, and other factors.
This helps prevent growth of microorganisms. It is preferable,
however, that the interior temperature of the temperature
switchable compartment 3 at the hot setting be kept at 80.degree.
C. or less. This contributes to low cost, because resin components
commonly used in refrigerators are resistant up to 80.degree.
C.
[0116] Microorganisms causing food poisoning are killed by heat;
for example, enterohaemorrhagic Escherichia coli (e.g., E. coli
O157) are killed when kept at 75.degree. C. for one minute. In
consideration of this, and also in consideration of the permitted
tolerance in the heater capacity and the temperature distribution
inside the temperature switchable compartment 3, it is particularly
preferable that the interior temperature of the temperature
switchable compartment 3 at the hot setting be kept at 80.degree.
C.
[0117] Here are the results of a test on how the numbers of food
poisoning microorganisms decrease when kept at 55.degree. C. A test
sample was prepared that in its initial state included
2.4.times.10.sup.3 CFU/mL of Escherichia coli, 2.0.times.10.sup.3
CFU/mL of Staphylococcus aureus, 2.1.times.10.sup.3 CFU/mL of
Salmonella, 1.5.times.10.sup.3 CFU/mL of Vibrio parahaemolyticus,
and 4.0.times.10.sup.3 CFU/mL of Bacillus cereus. The test sample
was first heated from 3.degree. C. to 55.degree. C. over 40
minutes, was then maintained at 55.degree. C. for 3.5 hours, and
was then cooled from 55.degree. C. to 3.degree. C. over 80 minutes;
then the number of the microorganisms were counted again. It was
found that the number of any of the kinds of microorganism tested
had decreased to 10 CFU/mL or less (i.e., below the detectable
level). This demonstrates that keeping the temperature switchable
compartment 3 at 55.degree. C. at the hot setting provides a
sufficient effect of reducing microorganisms.
[0118] As described above, the heater 15 is a heat-radiating
glass-tube heater. The heater 15 may be a heat-conducting heater
such as a sheet-shaped aluminum-deposited heater, which is
inexpensive but has a low heating rate. For this reason, with a
heat-conducting heater, when the temperature switchable compartment
3 is at the hot setting, the interior temperature thereof takes a
long time to pass through the temperature range from 30.degree. C.
to 45.degree. C., in which microorganisms actively grow, leading to
low safety in terms of food hygiene. A higher heating rate can be
achieved by increasing the heater capacity; this, however, cannot
be done above the temperature (normally, about 80.degree. C.) up to
which the component to which the heater is attached is resistant;
moreover, doing so may make the heat-radiating surface so large
that it extends up to a front part of the temperature switchable
compartment 3, increasing the risk of the user getting burned.
[0119] By contrast, a heat-radiating glass-tube heater has a high
heating rate, which contributes to safety in terms of food hygiene.
Furthermore, even a high-capacity heat-radiating glass-tube heater
occupies only a small area of space, and thus, as shown back in
FIG. 4, it can be arranged in a rear portion of the temperature
switchable compartment 3, and this reduces the risk of the user
getting burned. Therefore, it is more preferable that the heater 15
be a heat-radiating glass-tube heater.
[0120] The heater 15 is capable of being operated at an heat output
higher than is needed to maintain the interior temperature of the
temperature switchable compartment 3 at the hot setting, in which
cooked food are kept warm. The heat output of the heater 15 can be
changed by changing the energization rate of the heater 15. Hence,
rapid switching of the interior temperature of the temperature
switchable compartment 3 from the cold setting to the hot setting
can be achieved by operating the heater 15 at a high heat output,
and this makes the refrigerator 1 useful. When the interior
temperature of the temperature switchable compartment 3 reaches a
preset hot-setting temperature, it can be maintained at the preset
temperature by operating the heater 15 at a lower heat output.
[0121] For example, when, as the heater 15, a heater whose power
consumption is about 190 W and whose surface area is about 10,990
mm.sup.2 is used and operated at an energization rate of 100%, the
interior temperature of a temperature switchable compartment 3,
when it has a volume of about 0.023 m.sup.3, can be raised from
3.degree. C. up to 80.degree. C. in about 30 minutes. Then, by
operating the heater 15 intermittently at an energization rate of
15% (ON for 15 seconds and OFF for 85 seconds), the interior
temperature of the temperature switchable compartment 3 can be kept
about 80.degree. C. The blower 14 has a motor equipped with an
axial flow fan, and is operated so as to send air approximately at
a rate of 0.4 m.sup.3/m.
[0122] Here, while the temperature is kept constant, the surface
temperature of the heater 15 remains not higher than 250.degree.
C., and thus below the ignition point (494.degree. C.) of
isobutane, which is a flammable refrigerant. Thus, when, out of
consideration of the environment, isobutane, which is a flammable
refrigerant, is used as the refrigerant sealed in the refrigeration
cycle, even if isobutane leaks from the evaporator 17 or elsewhere,
there is no risk of the heat from the heater 15 causing an
explosion. This makes the refrigerator 1 safer to the user.
[0123] In the present embodiment, when the interior temperature of
the temperature switchable compartment 3 has reached a
predetermined temperature at the cold setting, the air inside the
temperature switchable compartment 3 may be circulated.
Specifically, with the temperature switchable compartment return
damper 20 so located as to keep the air return path 19 closed and
the communication path 36 open, and with the temperature switchable
compartment discharge damper 13 closed, the blower 14 is operated.
This makes it possible to produce a more even temperature
distribution inside the temperature switchable compartment 3 at the
cold setting.
[0124] Instead of opening and closing the air return path 19 and
the communication path 36 with the temperature switchable
compartment return damper 20, the air introduction path 12 and the
communication path 36 may be opened and closed with the temperature
switchable compartment discharge damper 13. This can be achieved by
provindig the temperature switchable compartment discharge damper
13 with a double-sided baffle similar to the one provided in the
temperature switchable compartment return damper 20.
[0125] When the double-sided baffle is positioned so as to keep the
air introduction path 12 open and the communication path 36 closed,
the cold air that has flowed into the temperature switchable
compartment 3 via the inlet port 33a flows out thereof via the
outlet port 33b, and is led to the air return path 19 via the
temperature switchable compartment return damper 20. On the other
hand, when the baffle is positioned so as to keep the communication
path 36 open and keep the air introduction path 12 closed, the air
circulates inside the temperature switchable compartment 3. This
makes it possible to reduce the cost of the refrigerator 1 and to
improve the volume efficiency thereof as effectively as in the case
described above.
[0126] A damper may be provided at the outlet port of the vegetable
compartment 5. In this case, when the temperature switchable
compartment 3 is switched from the hot setting to the cold setting,
closing the above-mentioned damper makes it possible to prevent the
hot air in the temperature switchable compartment 3 from flowing
back into the vegetable compartment 5. In addition, it is possible
to prevent the cold air in the vegetable compartment 5 from
reaching the double-sided baffle 20a and causing condensation
thereon.
[0127] The freezer compartment damper 22 is closed if, when the
temperature switchable compartment 3 is switched from the hot
setting to the cold setting, the blower 18 is not operated. This
prevents the hot air in the temperature switchable compartment 3
from flowing back into the freezer compartment 6 as the blower 14
is operated.
INDUSTRIAL APPLICABILITY
[0128] The present invention is applicable to a refrigerator
provided with a temperature switchable compartment whose interior
temperature can be switched by the user. The present invention is
also applicable to a refrigerator provided with, at the cold air
inlet side of a storage compartment, a damper for opening and
closing a cold air path.
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