JPH0445380A - Refrigerator with defreezing chamber - Google Patents

Abstract

PURPOSE:To enable a defreezing with little unevenness in temperature at each of a central part and a surface part to be realized within a short period of time and upon completion of the defreezing operation to enable a degree of freshness to be kept at such a temperature as one suitable for a raw food such as fish or meat or the like. CONSTITUTION:During a defreezing operation, a blower 18 is forcedly operated and a defreezing time is divided into three stages. At the first stage, an electrical energization for a far infrared ray heater 34 and a heating heater 42 is continuously carried out within a time period ranging from a starting of defreezing to a time in which a temperature of a temperature sensor 43 is increased up to a predetermined temperature and at the same time a damper thermostat 20 is forcedly released. At the second stage, an electrical energization for a far infrared ray heater 35 and a heating heater 42 is intermittently carried out for a specified period of time after a temperature of the temperature sensor 43 is increased up to a predetermined temperature and at the same time the damper thermostat 20 is forcedly released. At the third stage, after elapsing the second stage, the electrical energization for either the far infra-red ray heater or the heating heater is terminated. A heating capacity of both heaters is decreased from the second stage and then the damper thermostat is forcedly closed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigerator with a thawing chamber for thawing frozen foods.

[Prior Art] Conventionally, examples of refrigerators with a thawing chamber that use a heater to thaw frozen foods have been known. For example,
An example of this is shown in Japanese Patent No. 8-25414, and will be explained below with reference to FIGS. 7 and 8.

Reference numeral 1 denotes a thawing box, which includes an outer box 2 formed into a box shape of metal or synthetic resin, and an outer box 2 made of metal such as aluminum with good thermal conductivity and provided with an appropriate gap inside the outer box 2. It consists of an inner box 3. Reference numeral 4 denotes a linear heater, which is closely connected to the inner box 3 by means of aluminum foil 5 so that the bottom surface of the thawing box 1 is sparse and the top surface is densely packed.

6 is a heat insulating material interposed between the outer box 2 and the aluminum foil 5.

In this configuration, when the thawed food 7 is placed on the bottom of the thawing box 1 and the thawing action is started, heat is applied from the entire circumference of the inner box 3 by the heater 4, and the food 7 to be thawed is almost uniformly heated. It is characterized by heating and thawing it.

[Problems to be Solved by the Invention] However, in the conventional configuration, from the bottom of the thawing box 1,
Although heat is transferred to the bottom of the food 7 to be thawed by thermal conduction and the bottom can be thawed, the effect of radiant heat from the top and side surfaces of the thawing box 1 to the food 7 to be thawed is limited by the heating heater 4.
Since the wavelength of the heat rays transmitted through the inner box 3 is in the near-infrared region of 5 μm or less, there is almost no heat radiation, and heating is performed only by heat transfer due to convection of the warmed air inside the thawing box 1. For this reason, there is a problem that the thawing unevenness between the center and surface of the food 7 to be thawed tends to become large, and the thawing time also takes a long time. In addition, for the same reason, if food is left as is after thawing, especially perishable foods such as fish meat, the high ambient temperature will cause deterioration in quality, so the user must monitor the completion of thawing and dispose of the food. However, there was a problem that it could not be used with confidence.

In order to solve the problems of the prior art, the present invention properly controls the temperature during and after thawing, and provides a thawing chamber, especially in a refrigerator, that can thaw in a short time with less uneven thawing. The purpose is to

[Means for Solving the Problem] In order to achieve the above object, the refrigerator with a defrosting chamber of the present invention has the following features:
A freezer compartment, a refrigerator compartment, a thawing compartment, a cooler, a blower for forcing air cooled by the cooler into the freezing compartment, refrigerator compartment, and thawing compartment, and a remote control provided inside the thawing compartment. An infrared ray heater, a heating heater placed in close contact with the back side of the metal bottom plate, a temperature sensor placed in close contact with the back side of the bottom plate approximately in the center, and a temperature sensor provided at the entrance of the thawing chamber to detect the inflow of cold air. A refrigerator with a thawing chamber, which includes at least a damper thermostat that adjusts the damper thermostat, and a ventilation passage formed in the upper space of the thawing chamber, which is communicated with the damper thermos, and during thawing, the blower is forced to operate and the thawing time is 3. It is characterized in that it is divided into stages and includes the following control means, and a thawing control device that maintains the thawing chamber in a temperature range between the refrigerating temperature and the freezing temperature when not thawing.

First stage: From the start of thawing until the temperature of the temperature sensor rises to a predetermined temperature, the far-infrared heater and heating heater are continuously energized, and the damper thermo is forcibly released. do.

Second stage: After the temperature of the temperature sensor rises to a predetermined temperature, the far-infrared heater and heating heater are intermittently energized and the damper thermo is forcibly released within a certain period of time. .

Third stage: After the second stage has passed, the supply of electricity to at least one of the far-infrared heater or the heating heater is stopped, or the heat generation capacity of both heaters is lowered than in the second stage, and the damper Forcibly block the thermostat.

[Function] According to the configuration of the present invention described above, during normal thawing, far-infrared rays are directly radiated by the far-infrared heater from the top and side surfaces of the food to be thawed, and conductive heating is performed from the bottom heater. heat is absorbed. Further, in the first stage when the temperature sensor on the bottom rises to a predetermined temperature, both heaters are continuously energized and the temperature of the food to be thawed rises rapidly.

After that, the intermittent energization rate to both heaters is the second. The third stage and gradual decline, and the first stage. In the second stage, cold air is evenly supplied to the food to be thawed from the many ventilation holes on the top surface via the damper thermo, thereby suppressing the temperature rise on the food surface.

Then, in the third stage, power supply to at least one of the far-infrared heater or the heating heater is stopped, or the heat generation capacity of both heaters is lowered than in the second stage, and the damper thermo is forcibly closed. . Therefore, the damper thermo is forcibly closed and the exhaust heat in the thawing chamber is not recovered to the cooler side. Furthermore, if defrosting is started without putting food to be thawed by mistake, the power supply to both heaters is stopped to prevent each part from becoming abnormally high temperature.

Furthermore, after thawing, the damper thermostat will control the temperature.
Food temperature is automatically maintained in a temperature range between refrigeration temperature and freezing temperature to keep it cold.

[Embodiment 1] A refrigerator with a defrosting chamber according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

First, in Figure 3, 8 is the refrigerator body, outer box 9, inner box 1
0 and a heat insulating material 11 filled between these two boxes 9 and 10. Reference numeral 12 denotes a partition wall that divides the inside of the refrigerator main body 8 into upper and lower sections, and a freezer compartment 1 is provided in the upper part of the partition wall 12.
3. A refrigerating chamber 14 is defined in the lower part. Reference numeral 15 denotes a thawing chamber provided in an upper section of the refrigerator compartment 14.

16 is a compressor of a refrigeration cycle provided at the rear of the bottom of the refrigerator compartment main body 8, and 17 is a cooler housed in the back of the freezer compartment 13. 18 is a blower for forcing the cold air cooled by the cooler 17 into the freezing compartment 13, the refrigerator compartment 14, and the thawing compartment 15; 19.20 is provided at the entrance of the refrigerator compartment 14 and the thawing compartment 15; This is a damper thermostat that adjusts the amount of cold air flowing in using electrical input.

Its configuration is shown in Fig. 4 as a damper thermometer 20 for the thawing chamber 15.
will be explained using an example.

In FIG. 4, 21 is an electromagnetic coil, 22 is a plunger that moves the inner core of the electromagnetic coil 21 up and down depending on the presence or absence of electromagnetic action, 23 is a rod connected to the plunger 22, and 24 is a damper that opens and closes the cold air passage. When the electromagnetic coil 21 is energized, the electromagnetic action is applied to the rod 2.
3 is pushed up to open the damper 24, and when the current is cut off, the rod 23 falls downward and the damper 24 is closed.

Next, returning to FIG. 3, 25 and 26 guide the cold air from the blower 18 to the refrigerator compartment 14 and the thawing compartment 15 (discharge duct,
Reference numerals 27 and 28 designate suction ducts for returning the cold air that has cooled the refrigerator compartment 14 and the thawing compartment 15 to the cooler 17, respectively. Further, reference numerals 29, 30, and 31 are temperature detection means for detecting the temperatures in the freezing compartment 13, refrigerator compartment 14, and thawing compartment 15, respectively.

Next, the detailed structure of the defrosting chamber 15 will be explained with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, 32 is an outer box made of synthetic resin, and 33 is a heat insulating material installed on the inner surface of the outer box 32 to surround the outer periphery. 34 is a far-infrared heater installed in the upper part of the thawing chamber 15, and a ceramic paint layer 37 containing silicon or the like as a main component is baked on the surface of a glass tube 36 in which a heater wire 35 is enclosed to form a coating with a thickness of about 5 μm or more. It is configured to effectively emit far-infrared rays. This far-infrared heater 34 is suspended and supported by a dome-shaped reflector plate 39 made of metal such as aluminum through a holder 38 made of synthetic resin with high heat resistance. In addition, the reflector plate 39 is integrally formed with the inner box portions that constitute both side walls and the back wall of the thawing chamber 15, and a large number of ventilation holes 40 are formed in the flat portions on both sides of the top dome portion. ing.

Next, reference numeral 41 denotes a bottom plate made of metal such as aluminum, and a linear heater 42 is tightly fixed to the back surface of the bottom plate with aluminum foil 43 or the like for heat conduction.

A thawing tray 44 is detachably installed on the bottom plate 41, and is composed of a tray 46 made of metal such as aluminum on which the food to be thawed 45 is placed, and a frame 47 made of synthetic resin surrounding the outer periphery. . 48 is a protective net for preventing burns that is fixedly installed below the reflector plate 39 at a certain interval;
A door 9 opens and closes the front opening of the thawing chamber 15. Further, reference numeral 50 denotes a ventilation passage formed in the space on the back surface of the reflector plate 39, which communicates with the damper thermometer 20 via a discharge port 51. Reference numeral 52 denotes a suction port formed in the back wall of the thawing chamber 15 and communicates with the suction duct 28 .

Next, the functions of the refrigerator with a defrosting chamber of this embodiment will be explained using FIG.

In FIG. 5, 53 is a defrost switch provided on the front surface of the outer shell of the refrigerator main body 8.

The electric circuit and control circuit will be explained below using FIG. 5.

The compressor 16 and the blower 18 are connected to a power source via a relay contact 54 and a relay contact 55, respectively. The far-infrared heater 34 and the heater 42 are connected to a power source through a relay contact 56 and a relay contact 57, respectively. Also, the electromagnetic coil 21 of the damper thermo for the thawing chamber,
The electromagnetic coils 21' of the damper thermos for the refrigerator compartment are each connected to the power supply via relay contacts 58, 59.

Reference numeral 60 denotes a freezer temperature control device, which includes a temperature detector 29 such as a thermistor, resistors R1, R2, R3, a comparator circuit including a comparator 61, a transistor 62, and a relay coil 63, and the output of the comparator 61 is Connected to the base of transistor 62. Further, the collector of the transistor 62 is connected to the relay coil 63 for attraction, which opens and closes the relay contact 54 . 6
Reference numeral 4 denotes a refrigerator temperature control device, which includes a temperature detector 30 such as a thermistor, resistors R4, R5, R6, a comparator circuit including a comparator 65, a transistor 66, and a relay coil 67. Connected to the base of transistor 66. Further, the collector of the transistor 66 is connected to the relay coil 67 for attraction, which opens and closes the relay contact 59. 68
is a thawing chamber temperature control device, and a temperature sensor such as a thermistor 3
1. It is equipped with a comparison circuit including resistors R7, R8, R9, a comparator 69, an OR circuit 70, an AND circuit 70a1, a transistor 71, and a relay coil 72. During normal cooling, the temperature inside the thawing chamber 15 is approximately -3°C. The temperature is controlled to the partial freezing temperature of . The output of the comparator 69 is connected to one input of the OR circuit 70. Further, the output of the OR circuit 70 is connected to the base of the transistor 71 via the AND circuit 70a, and the collector of the transistor 71 is connected to the base of the transistor 71 through the AND circuit 70a.
The relay coil 72 for suction, which opens and closes the relay contact 58, is connected.

73 is a thawing control device, which connects the thawing chamber 15c) to the bottom plate 4;
1, a temperature sensor 43, a resistor RIO1R11,
R12, comparator 74 and resistors R13, R14, R
15, two comparison circuits equipped with a comparator 74a,
Timer 75.76.77.77a, 90, AND circuit 78.79.79a10R circuit 80.81.82, OR circuit 70, inverter 83, inverter 83a, h
Langimeta 84.8.5.86, relay coil 87.8
8.89 and the defrosting switch 53.

The output of the defrosting switch 53 is connected to the input of the timer 75, and the output of the timer 75 is connected to the AND circuit 78.79a10R circuit 70.82.
are connected to one input of each. The output of the comparator 74 is connected to the AND via the inverter 83.
It is connected to the other input of the circuit 78 and simultaneously connected to one input of the AND circuit 79. The output of the comparator 74a is connected to the other input of the AND circuit 79a via a timer 90 and an inverter 83a, and the output of the AND circuit 79a is connected to the other input of the AND circuit 79. . The output of the AND circuit 78 is connected to one of the OR circuits 80.81a, and the output of the AND circuit 79 is connected to the input of the timer 76.77.77a. The outputs of the timers 76 and 77 are connected to the other inputs of the OR circuits 80 and 81, and the outputs of the OR circuits 80 and 81 are respectively connected to the bases of the transistors 84 and 85. There is. The collector of the transistor 84.85 has the relay contact 56.5.
The relay coils 87 and 88 for suction that open and close 7 are connected. The output of the timer 77a is
Along with the output of the OR circuit 70, the AND circuit 70
connected to one input of a. Further, the other input of the 0R circuit 82 is connected to the freezer compartment temperature control device 6.
The output of the comparator 61 of O is connected, and the output of the comparator 61 of O
The output of R circuit 82 is connected to the base of transistor 86. A suction relay coil 89 for opening and closing the relay contact 55 is connected to the collector of the transistor 86.

Here, the timer 75 is set to "High" once for the input.
(Hereafter simply referred to as "H") signal is input for a predetermined time t.
The “H” signal continues to be output during this period, and then “LOW” (
The timers 76 and 77 alternate between "H" and "L" signals for a predetermined period of time while the "H" signal is being input to the input. However, the intermittent output rate of the "H" signal is configured to decrease stepwise as a predetermined time elapses.

For example, specifically, the output of the timer 76 is such that the output rate of the "H" signal is 80% at the first time t1, and the output rate of the "H" signal is 80% at the next time t2.
In this case, the configuration is such that the output rate of the "H" signal is 40%,
The output of the timer 77 is "H" for the first time 1+-
The output rate of the "H" signal is 80%, and the output rate of the "H" signal is 0% at the next time t2-.The operating time of the timers 76 and 77 is t+ +t2=tl
-+t2-, and the predetermined time t of the timer 75 is the operating time t+ of the timers 76 and 77, including the time-safe role of the defrosting action.
+t2 = t+ −+t2− is set to be sufficiently longer. Further, the output of the timer 77a is normally "H", and when "H" is input to the input of -1, the timer 77a outputs "H". =1. -, the output continues to be "H", and then becomes "L" at time t2=t2-.

In this configuration, when the temperature of the freezer compartment 13 is higher than a predetermined value, the resistance value of the temperature detector 29 is small and the output of the comparator 61 becomes H'', so the transistor 62 is turned on and the relay coil 63 is turned on. Therefore, the relay contact 54 is closed and the compressor 16 is operated.

At the same time, the output of the OR circuit 82 also becomes "H", so the transistor 86 is turned on and the relay coil 89 becomes conductive. Therefore, the relay contact 55 is closed and the blower 18 is also operated to forcefully ventilate cold air to the freezing compartment 13, refrigerator compartment 14, and thawing compartment 15 to perform cooling.

Thereafter, when the freezer compartment 13 is cooled to a predetermined temperature, the resistance value of the temperature detector 29 increases and the output of the comparator 6 becomes "L". Therefore, the transistor 62 is 0FF.
Since the output of the OR circuit 82 also becomes "L", the transistor 86 is also turned off, and the power to the relay coil 63.89 is cut off. Therefore, both relay contacts 54 and 55 are opened, and the compressor 16 and blower 18 are stopped. Thereafter, this action is repeated until the inside of the freezer compartment 13 reaches a predetermined temperature (for example, -20
The temperature is maintained at ℃).

Next, when the temperature of the refrigerator compartment 14 is higher than a predetermined value, the resistance value of the temperature detector 30 is small, and the comparator 6
Since the output of 5 becomes "H", the transistor 66 turns on.
Then, the relay coil 67 becomes conductive. Therefore, the relay contact 59 is closed, the electromagnetic coil 21- is energized, the damper 24' of the damper thermostat 19 is opened, and cold air is introduced into the refrigerator compartment 14 to perform a cooling effect.

Thereafter, when the refrigerator compartment 14 is cooled to a predetermined temperature, the resistance value of the temperature detector 30 becomes large and the comparator 65
As a result, the transistor 66 is turned off, the current to the relay coil 67 is cut off, the relay contact 59 is opened, and the current to the electromagnetic coil 21' is also cut off. Then, the damper 24' of the damper thermostat 19 is closed to prevent cold air from flowing into the refrigerator compartment 14. Thereafter, this action is repeated to maintain the temperature inside the refrigerator compartment 14 at a predetermined temperature (for example, 5° C.).

Further, when the temperature of the thawing chamber 15 is higher than a predetermined value when not thawing, the resistance value of the temperature detector 31 is small, and the output of the comparator 69 becomes "H", f=? h
OR circuit 70. The output of the AND circuit 7゜a becomes H'', the transistor 71 turns on, and the relay coil 72 becomes conductive. Therefore, the relay contact 58 closes and the electromagnetic coil 21
is energized, the damper 24 of the damper thermostat 20 is opened, and cold air is introduced into the thawing chambers 1 and 5 to perform a cooling action. Thereafter, when the thawing chamber 15 is cooled to a predetermined temperature, the resistance value of the temperature detector 31 increases (and the comparator 6
The output of 9 becomes "L". Therefore, the output of the OR circuit 70 becomes "L" and the output of the AND circuit 70a also becomes "L", and the transistor 71 is turned off and the relay coil 72
The power supply to the electromagnetic coil 21 is cut off, the relay contact 58 is opened, and the power supply to the electromagnetic coil 21 is also cut off. And damper thermo 20
The damper 24 is closed to prevent cold air from flowing into the thawing chamber 15. Thereafter, this action is repeated until the thawing chamber 15
As mentioned above, the temperature inside the container is maintained at a third temperature range between the freezing temperature and the refrigeration temperature suitable for preserving fresh foods, that is, the partial freezing temperature range of about -3°C.

Next, we will discuss the action during thawing. First, the food to be thawed 45 to be thawed is placed on the thawing tray 44 and placed on the bottom plate 41 in the thawing chamber 15, and then the thawing switch 5 is turned on.
Insert 3. At the same time as the input, the timer 75 starts outputting an "H" signal, and one input of the AND circuit 78, 79a becomes "H". At this time, the bottom plate 41 of the thawing chamber 15 is connected to the frozen food 4 which is at a low temperature (for example, -20°C).
The temperature decreases due to heat conduction with the thawing tray 44 on which the food 5 is placed. That is, the temperature sensor 43 is in a sufficiently low temperature state. Therefore, the outputs of comparators 74 and 74a are both "L", and the signals inverted to "H" by inverters 83 and 83a are input to the other inputs of AND circuits 78 and 79a, respectively. . Therefore, AND
Since the inputs of the circuit 79a are both “H”, the output is “H”
and is input to one input of the AND circuit 79.

On the other hand, the AND circuit 79 does not include the inverter 83.
The "L" signal is input as is. Therefore, the output of the AND circuit 78 is "H" and the output of the AND circuit 79 is "L".
Therefore, the timers 76 and 77 do not operate, and the outputs of the OR circuits 80 and 81 become "H" and the transistors 84 and 84.
85 turns on. Then, the relay coils 87 and 88 are energized, the relay contacts 56 and 57 are closed, and the far-infrared heater 34 and the heating heater 42 are continuously energized.

Then, when the thawing action progresses and the temperature sensor 43 rises to a predetermined temperature (for example, 20 ° C.) (the time required for this is t, and this period is defined as the first stage), The output of the comparator 74 becomes "H", the "L" signal is input to the AND circuit 78 via the inverter 83, and the output of the AND circuit 78 becomes "L". At this time,
The output of the comparator 74a remains unchanged at "L".

On the other hand, since the "H" signal is input to the AND circuit 79, the timers 76 and 77 go "H" and "L" at a predetermined intermittent rate.
" signal starts to be output repeatedly. Therefore, the transistor 84.85 is turned on and off through the OR circuit 80.81 at an intermittent output rate corresponding to that signal.Then, the energization to the relay coil 87.88 is interrupted. The relay contacts 56 and 57 open and close intermittently.

As a result, the far infrared heater 34 is continuously energized for a period of time t.
. 1+ (this period is the second stage)
is controlled so that the energization rate is 80%, and the energization rate is 40% at the next time t2 (this period is defined as the third stage), so that the heat generation capacity is gradually reduced as time passes. Further, the heater 42 is continuously energized for the time t. Control is performed such that the energization rate is 80% during the following time t1-, and 0% during the next time t2-, so that the heat generation capacity is reduced.

In this way, in the early stage of thawing when the temperature of the food to be thawed 45 is low, both the far-infrared heater 34 and the heating heater 42 are continuously energized until the temperature of the temperature sensor 43 rises to a predetermined temperature (for example, 20° C.). Foods to be thawed 45
Even if the weight of the food changes, depending on the degree of temperature rise of the temperature sensor 43, thawing will proceed rapidly under conditions with a large amount of heat generation for a time appropriate for each weight. Time can be shortened.

Thereafter, the heat generation capacity gradually decreases with the passage of time, and the thawing of the food 45 progresses while suppressing the rise in the surface temperature of the food 45 to be thawed. During thawing, the food to be thawed 45 is uniformly heated by radiation from the far-infrared heater 34 from the top surface, coupled with the reflection action of the reflector plate 39, and is simultaneously heated by conduction from the bottom surface by the heater 42. It will be done.

Here, in heating by the far infrared heater 34, far infrared rays with a long wavelength of 5 μm or more are radiated to the food to be thawed 45, so that general foods having an absorption wavelength band in the far infrared wavelength range can be efficiently Far infrared rays are absorbed and the food to be thawed 4
Thawing proceeds in a state where the temperature unevenness between the surface portion and the center portion does not become relatively large as it penetrates relatively far into the inside of the portion 5. Further, in heating by the heater 42, the bottom portion of the food to be thawed 45, which cannot be sufficiently heated by the far-infrared heater 34, can be thawed by heat conduction heating via the thawing plate 44.

On the other hand, at the same time as the heating action by the far-infrared heater 34 and the heating heater 42, the OR circuit 82 is activated during defrosting, that is, during the first, second, and third stages in which the output of the timer 75 continues to generate an "H" signal. The output becomes “H” and transistor 8
6 is turned on, and the relay coil 89 becomes conductive. For this reason,
The relay contact 55 closes and the blower 18 is forced to operate regardless of the output of the freezer temperature control device 60.

Meanwhile, during this period, the output of the timer 77a is "L" due to the output of the AND circuit 79 which is "L" due to the output of the comparator 74 being "L" in the first stage. When the output of the AND circuit 79 changes to "H", the output of the timer 77a changes to "H" in the second stage.
The third stage is "L". Therefore, the AND circuit 70
The output of a is also “H” in the first and second stages, and “H” in the third stage.
The transistor 71 is turned on during that time.

It turns ON and OFF. That is, during thawing, the damper 24 of the damper thermometer 20 for the thawing chamber has a pattern in which the first and second stages are forcibly opened, and the third stage is forcibly closed.

In this way, the first and second stages are the open damper 2
The cold air forcedly ventilated by the blower 18 through the air blower 18 flows through the discharge duct 26 and into the ventilation passage 50 in the upper part of the thawing chamber 15 through the discharge port 51. The cold air that has flowed into the ventilation path 50 is discharged downward from a large number of ventilation holes formed in the reflection plate 39, and evenly cools the surface of the food to be thawed 45.

Due to this action, the food 45 to be thawed is mainly affected by the far-infrared radiation effect of the far-infrared heater 34 and the far-infrared radiation effect of the far-infrared heater 34.
In addition to the effect of the control that gradually reduces the heat generation capacity of the heaters 4 and 42, the temperature rise at the surface is further suppressed, resulting in uneven thawing with a small temperature difference between the center and the surface. Decompression progresses with less.

Then, after the thawing has progressed considerably and the second stage ends (for example, when the center temperature of the food to be thawed 45 is around 15° C.), the damper 24 of the damper thermostat 20 is forcibly closed. Defrosting progresses gradually without introducing cold air and with a small amount of heat generated by the heater. During this time, the temperature of the food to be thawed 45 is also rising, so the heating efficiency of the heater and the heat absorption efficiency of the food to be thawed 45 are decreasing, but since the damper 24 is blocked, the temperature inside the thawing chamber 15 is The remaining heat is not recovered from the suction port 52 and is not returned to the cooler 17. Therefore, the amount of heat load on the cooler 17 is reduced accordingly, and the compressor 1
6 extra driving is avoided.

Note that FIG. 6 shows the temperature characteristics and time chart of the food to be thawed 45 during thawing.

In FIG. 6, for example, a temperature of 20 DEG C. is the predetermined temperature in the present invention, and a time t. Indicates that t is the first stage, t is the second stage, and t2 is the third stage.

In addition, regarding the thawing time, the internal penetration effect of far infrared rays and continuous heating control in the initial stage of thawing make it possible to thaw in a relatively short time (for example, about 30 minutes for a tuna weighing 500 g and 25 mm thick). Since the plate 39 is exposed in the ventilation path 50, the temperature of the surrounding members of the reflector plate 39 itself, which is originally quite high in temperature, is cooled and lowered, which is advantageous in terms of safety.

As this thawing action progresses, the following time to +t
+ +t2 =to -+tI -+t2 -i.e.
When the total time of the first, second, and third stages has elapsed, the outputs of the timers 76 and 77 become "L", and the output of the timer 75 is also "L" due to input from the timer 76 to the reset terminal of the retimer 75. It becomes “L”. Therefore, transistors 84, 85 are turned off, and relay coils 87.
88 is cut off, relay contacts 56 and 57 are opened, and the far infrared heater 34 and heating heater 42 are cut off, and thawing is completed. Similarly, the OR circuit 82
Since one of the inputs becomes "L", the forced operation state of the blower 18 is canceled. Also, the output of the timer 77a is
In order to return to "H", one input of the AND circuit 70a becomes "H", and the forcibly closed state of the damper 24 of the damper thermos 20 for the defrosting chamber is released.

After thawing, the temperature sensor 3
The temperature inside the defrosting chamber 15 is controlled based on the detected temperature. Therefore, the food to be thawed 45 after thawing is immediately cooled to stabilize in the partial freezing temperature range of approximately -3°C, and the temperature does not further rise due to residual heat.

Even if you leave it as it is after thawing, it is kept cool at a partial freezing temperature range of approximately -3°C, which is suitable for preserving perishables such as fish and meat, so the user does not have to monitor the end of thawing as usual. The food 45 can be thawed safely without the need for immediate processing, and the food to be thawed 45 can be used at any time after thawing, making it extremely convenient to use.

Next, we will explain what happens when the temperature rises excessively, such as when thawing is started in an empty state. When the temperature of the temperature detector 43 continues to rise and exceeds the first set temperature (for example, 20°C) and reaches the second set temperature (for example, 40°C), the output of the comparator 74a becomes "H" and the timer is activated. 90 is activated and after a predetermined time “H”
” is inverted to “L” by the inverter 83a, and the signal is input to one input of the AND circuit 79a.

Therefore, the output of the AND circuit 79a becomes "L" and
It is input to one input of the circuit 79. Therefore, the output of the AND circuit 79 is "L", so the timers 76 and 77 do not operate, and one input of the OR circuit 80 and 81 is both "L".
” signal is input.

On the other hand, since the AND circuit 78 continues to output the "L" signal, the "L#" signal is also input to the other input of the OR circuit 80181.

Therefore, the outputs of the OR circuits 80, 81 are both "L", the transistors 84, 85 are turned off, and the -L coils 87, .
The energization to the far-infrared heater 34 and the heating heater 42 is stopped, and the relay contacts 56 and 57 are opened.

Therefore, when the temperature rises excessively, both heaters are forcibly turned off, so that thermal deformation of each part of the defrosting chamber 15 can be prevented.

As described above, the refrigerator with a defrosting chamber of this embodiment provides the following effects.

■ Far-infrared radiant heating by far-infrared heater from the top,
Heat can be efficiently heated from both sides by heat conduction heating by the heater from the bottom, and the heat generation capacity of both heaters gradually decreases during thawing, and this also combines with the effect of far infrared rays penetrating into the inside of the food being thawed. This allows for thawing with less unevenness in temperature between the center and surface.

■ The far-infrared heater and heating heater are continuously energized until the temperature sensor installed on the bottom plate of the thawing chamber rises to a predetermined temperature, so even if the weight of the food to be thawed changes, the
Rapid heating can be performed using the maximum capacity heater for only a certain amount of time, making it possible to defrost food in a short time.

■ During the first and second stages of thawing, the damper thermo for the thawing chamber is forcibly opened and the blower is forced to operate continuously, allowing food to be thawed to be thawed through the ventilation passage formed in the space on the back of the reflector. On the other hand, since the cold air is allowed to descend and flow in, the surface of the food to be thawed is evenly cooled, temperature rise is further suppressed, and thawing with less unevenness can be achieved.

■ During the third stage of defrosting, the damper thermo is forcibly closed, so the residual heat in the defrosting chamber is not returned to the cooler and does not become a heat load. Therefore, extra cooling operation of the compressor can be reduced.

- During thawing, the reflector and other peripheral components that would normally be at high temperatures are exposed to the ventilation path and cooled, which lowers the temperature, which is advantageous for safety.

- Even if an abnormal temperature rise occurs during thawing, both heaters are forcibly turned off, so thermal deformation of various parts of the thawing chamber can be prevented, eliminating safety issues.

■ After thawing, the temperature inside the thawing chamber is kept between the freezer and refrigerator temperatures (for example, the partial freezing temperature range of approximately -3°C), so the residual heat immediately after thawing will lower the temperature of the food to be thawed. It does not rise further, and even if left as is, the freshness is maintained at a temperature suitable for raw foods such as fish meat, and the food can be used at any time.

[Effects of the Invention] According to the present invention described above, temperature control during and after thawing can be made appropriate, and a refrigerator with a thawing chamber that can thaw in a short time can be provided with less uneven thawing. You can achieve excellent results.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a thawing chamber showing one embodiment of the present invention;
The figure is a sectional view taken along line A-A of the thawing chamber shown in Fig. 1, Fig. 3 is a longitudinal sectional view of a refrigerator with a thawing chamber equipped with the thawing chamber shown in Fig. 1, and Fig. 4 is the sectional view taken along the line AA- Fig. 5 is an electric circuit and control circuit diagram of the refrigerator with a thawing chamber shown in Fig. 3, and Fig. 6 is a time chart during thawing and a diagram of the food to be thawed. FIG. 7 is a perspective view of a thawing box showing a conventional example, and FIG. 8 is a sectional view of the thawing box taken along line B--B in FIG. 7. 13... Freezer room, 14... Refrigerator room, 15... Thawing room, 16... Compressor, 17... Cooler, 18...
Blower, 20... Damper thermo, 34... Far infrared heater, 39... Reflector, 40... Ventilation hole, 41
... Bottom plate, 42 ... Heater, 43 ... Temperature detector, 44 ... Thawing dish, 45 ... Food to be thawed, 4
9... Door, 50... Ventilation path, 73... Thawing control device. 15. Thawing chamber 31.43... Thawing chamber temperature detection means 34... Far infrared heater Fig. 1 Fig. 3 N1 g1Ic4 Fig.

Claims (1)

[Scope of Claims] A freezer compartment, a refrigerator compartment, a thawing compartment, a cooler, a blower for forcing air cooled by the cooler into the freezing compartment, refrigerator compartment, and thawing compartment, and the thawing compartment. a far-infrared heater provided inside the thawing chamber, a heating heater placed in close contact with the back surface of the metal bottom plate, a temperature sensor placed in close contact with the substantially center of the back surface of the bottom plate, and a far infrared heater provided at the entrance of the thawing chamber. A refrigerator with a thawing chamber, which includes at least a damper thermostat that adjusts the amount of cold air flowing in, and a ventilation passage formed in the upper space of the thawing chamber, which is communicated with the damper thermometer, and during thawing, the blower is forced to operate and the thawing chamber is thawed. A refrigerator with a thawing chamber, which divides the time into three stages, is equipped with the following control means, and is equipped with a thawing control device that maintains the thawing chamber in a temperature range between the refrigerating temperature and the freezing temperature when not thawing. . First stage: From the start of thawing until the temperature of the temperature sensor rises to a predetermined temperature, the far-infrared heater and heating heater are continuously energized, and the damper thermo is forcibly released. do. Second stage: After the temperature of the temperature sensor rises to a predetermined temperature, the far-infrared heater and heating heater are intermittently energized and the damper thermo is forcibly released within a certain period of time. . Third stage: After the second stage has passed, the supply of electricity to at least one of the far-infrared heater or the heating heater is stopped, or the heat generation capacity of both heaters is lowered than in the second stage, and the damper Forcibly close the thermostat.