JPH03140786A - Refrigerator equipped with defrosting chamber - Google Patents

Abstract

PURPOSE:To provide a refrigerator with a defrosting chamber, capable of defrosting in a short period of time, especially in the refrigerator by a method wherein a fan is operated forcibly during defrosting, a heater is conducted continuously until the temperature of a bottom plate is risen to a predetermined temperature, then, the rate of conduction is reduced stepwisely and a damper thermostat is opened in first and second stages while the damper thermostat is closed in a third stage. CONSTITUTION:Foods 45 to be defrosted are but on a bottom plate 41 in a defrosting chamber 15 and, then, a defrosting switch is thrown. Then, heaters 34, 42 are conducted continuously. When defrosting operation is advanced and a temperature detected by a temperature detector 43 is risen to a predetermined temperature (first stage), the heaters 34, 42 are controlled so that the heat generating capacities of them are reduced stepwisely in accordance with the elapse of time from a time (t1) (second stage) next to the time (to) of continuous conduction and next time (t2) (third stage). On the other hand, a fan 18 is operated forcibly and simultaneously with the heating operations of the far-infrared ray heater 34 and the heater 42. Further, the damper 24 of a damper thermostat 20 is opened forcibly in the first and second stages and, then, is closed forcibly in the third stage.

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.

2. Description of the Related Art Conventionally, it is known that a heater is used to thaw frozen foods. For example, there is an example shown in Japanese Patent Publication No. 48-25414, which 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, etc., and an inner box of the outer box 2 made of aluminum or the like with good thermal conductivity, with an appropriate gap provided between the inner box. It is composed of an inner box 3 made of metal. Reference numeral 4 denotes a linear heater, and the thawing box 1 is closely connected to the inner box 3 by means of aluminum foil 6 so that the bottom surface of the thawing box 1 is sparse and the top surface thereof is densely packed.

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

In this configuration, when the food 7 to be thawed 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 heating of the heater 4, and the food to be thawed is almost uniformly heated. 7 is heated to thaw it.

Problem to be Solved by the Invention However, with such a configuration, heat is transferred from the bottom of the thawing box 1 to the bottom of the food 7 to be thawed by thermal conduction. The effect of radiant heat on the food 7 to be thawed from the top and side surfaces of the thawing box 1 is almost negligible since the heat ray wavelength from the heater 4 through the inner box 3 is in the near-infrared region of 5 μm or less. Heating occurs only by heat transfer by convection of warmed air. For this reason, there are disadvantages in that the food to be thawed 7 tends to be thawed unevenly between the center and the surface, and also takes a long time to thaw.
If food is left as it is after thawing, especially perishable foods such as fish meat, the high ambient temperature will cause deterioration, so the user needs to monitor and dispose of the food until the thawing is complete, so it can be used with confidence. There was a drawback that there was no

The present invention is intended to solve the above-mentioned problems, and it is an object of the present invention to particularly provide a thawing chamber in a refrigerator with less uneven thawing and capable of thawing in a short time.

Means for Solving the Problems In order to solve the above problems, the refrigerator with a defrosting chamber of the present invention has the following features:
A far-infrared heater and a reflector plate covering the top in a dome shape are installed on the top surface of the thawing chamber, and a bottom plate with a heating heater and a temperature sensor attached to the bottom surface is installed, and the food to be thawed is placed on the bottom plate. The configuration is such that a thawing dish is installed. Then, a ventilation path is formed in the space on the back side of the reflector plate and communicated with a damper thermometer for adjusting the amount of cold air inflow, which is installed at the cold air inlet of the thawing chamber.
A large number of ventilation holes are formed in the reflection plate. For such a configuration, the blower is forced to operate during thawing, and the far-infrared heater and heating heater are continuously operated from the start of thawing until the temperature of the temperature sensor on the bottom plate rises to a predetermined temperature in the first stage. Afterwards, electricity is applied to both heaters intermittently in the second and third stages, and the intermittent energization rate is gradually lowered.The freezer is brought to a third temperature between the refrigeration temperature and freezing temperature. A thawing control device is provided to maintain the thawing in the belt.

Effect of the present invention With the above-described configuration, far-infrared rays are directly radiated by the far-infrared heater and indirectly radiated through the reflector from the top and side surfaces of the food to be thawed, and conductive heating is performed from the bottom heater. heat is absorbed.

In addition, 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 changed to the second stage. The third stage and gradual decline, and the first stage. In the second stage, cold air is uniformly supplied to the food to be defrosted from the many ventilation holes formed on the top surface of the reflector via the damper thermo, thereby suppressing the temperature rise on the food surface. Then, in the third stage, the damper thermo is closed and the exhaust heat in the thawing chamber is not recovered to the cooler side.

Further, after thawing is completed, the temperature of the food is automatically maintained in the third temperature range between the refrigeration temperature and the freezing temperature by the temperature control function of the damper thermo, and the food is kept cold.

EXAMPLE A refrigerator with a defrosting chamber according to an example of the present invention will be described below with reference to FIGS. 1 to 6.

8 is the refrigerator body, which includes an outer box 9, an inner box 10, and both boxes 9,
It is composed of a heat insulating material 11 filled between 10 and 10.

12 is a partition wall that partitions the inside of the refrigerator main body 8 into upper and lower parts;
A freezing compartment 13 is provided in the upper part of the partition wall 12, and a refrigerator compartment 14 is provided in the lower part.
are divided into sections. Reference numeral 16 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 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 16;
Reference numeral 9.20 is a damper thermometer installed at the entrance of the refrigerator compartment 14 and the thawing compartment 15 to adjust the inflow of cold air by electrical input.The structure of the damper thermostat 20 will be explained by taking the damper thermos 20 for the thawing compartment 16 as an example. 21 is an electromagnetic coil μ, 22 is a plunger that moves the inner core of the electromagnetic coil /l/21 up and down depending on the presence or absence of electromagnetic action, 23 is a rod connected to the plunger n, and 24 is a damper that opens and closes the cold air passage. When the electromagnetic coil 21 is energized, the rod 23 is pushed up by the electromagnetic action and the damper 24 is opened. When the energization is cut off, the rod 23 falls downward and the damper/<-24. It is configured to close. still,
Although not shown, for convenience of explanation later, the electromagnetic coils of the damper thermostat 19 for the refrigerator compartment having the same configuration will be referred to as 21' and damper thermo'.

25 and 26 supply cold air from the blower 18 to the refrigerator compartment 1.
4. A discharge duct leading to the thawing chamber 15), 27, and 28 are suction ducts for returning the cold air that has cooled the inside of the refrigerator chamber 14 and the thawing chamber 16 to the cooler 17, respectively. Also, 29,30
．． 31 are the freezing chamber 13, the refrigerator chamber 14, and the thawing chamber 15, respectively.
This is a temperature sensor that detects the temperature inside the device.

Next, the detailed configuration of the thawing chamber 16 will be explained.

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 the thawing chamber 1
There is a far infrared heater installed at the top of the heater wire 3.
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 glass tube 36 is sealed to effectively emit far infrared rays of about 6 μm or more. This far infrared heater 34 is made of a holder 3 made of synthetic resin with high heat resistance.
It is supported by a dome-shaped reflector plate 39 made of metal such as aluminum through a dome-shaped reflector plate 39 . In addition, the reflector plate 39 is formed integrally with the inner box portions that constitute both side walls and the back wall of the thawing chamber 15, and furthermore, a large number of ventilation holes 4o are formed in the flat portions on both sides of the top dome portion. are doing. Next, 41 is a bottom plate made of metal such as aluminum, 42 is a linear heater fixed thermally conductively to the back surface of the bottom plate 41 with aluminum foil, and 43 is the bottom plate. This is a temperature sensor that is placed in close contact with the center of the back surface of 41 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 46 is placed, and a frame 47 made of synthetic resin surrounding the outer periphery. .

Reference numeral 48 is a protective net for preventing burns fixed at a constant interval below the reflecting plate 39, and 49 is a door that opens and closes the front opening of the thawing chamber 16. 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 61. Reference numeral 62 denotes a suction port formed in the back wall of the thawing chamber 16, which communicates with the suction duct 28. 63 is a defrost switch provided on the front surface of the outer shell of the refrigerator main body 8.

Next, the electric circuit and control circuit will be explained.

The compressor 16 and the blower 18 are connected to a power source through a relay contact 54 and a relay contact 66, respectively. The far-infrared heater 34 and the heater 42 are connected to a power source through a relay contact 66 and a relay contact 67, respectively. Also, electromagnetic coil / L'2 of damper thermo for thawing room.
1. Electromagnetic coil of damper thermo for refrigerator/l/21'
are connected to the power supply via relay contacts 58 and 59, respectively.

Reference numeral 6o 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 pace of transistor 62. Further, the collector of the transistor 62 is connected to the relay coil /1/63 for attraction, which opens and closes the relay contact 64.

Reference numeral 64 denotes a refrigerator room temperature control device, which includes a temperature sensor 30 such as a thermistor. Comparison circuit with resistors R4, R6, R6, comparator 86, transistor 66, relay coil fiy6
7, and the output of the comparator 66 is connected to the pace of the transistor θ6. Further, the collector of the transistor 66 is connected to the relay coil 67 for attraction, which opens and closes the relay contact 69.

68 is a thawing chamber temperature control device, which includes a temperature detector 31 such as a thermistor, resistors R7, R8, R9, a comparator circuit including a comparator 69, and an OR circuit 70. It is equipped with an AND circuit 70a, a lung staff 1, and a relay coil 72, and is configured with a resistor so that the temperature inside the thawing chamber 150 is controlled to a partial freezing temperature of about -3° C. during normal cooling.

The output of the comparator 69 is connected to one input of the OR circuit 70.

Further, the output of the OR circuit 7o is connected to the pace of the transistor 71 via the AND circuit 70a, and the collector of the transistor 71 is connected to the relay coil/L/72 for suction that opens and closes the relay contact 58. ing.

Reference numeral 73 denotes a thawing control device, which includes a temperature sensor 43 closely attached to the bottom plate 41 of the thawing chamber 16, and a resistor R1°.

R11, R12, comparison circuit with comparator 74 and tie-r-75, 76, 77, 77a, AND circuit 7s
, 79.0 RDo road so , 81 , 82, said O
R circuit 70. Inverter 83, transistor 84°85
．． 86, relay coil/L/87, 88, 89, and the defrosting switch 63.

The outlet of the defrosting switch 63 is connected to the timer 7.
6, and the output of the timer 76 is connected to the inputs of the AND circuits 78, 791 . ○Connected to one input of each of the R circuits 70 and 82. The comparator 74
The output is sent to the AND circuit 7 via the inverter 83.
At the same time, it is connected to the other input of the AND circuit 79. said AND
The output of the circuit 78 is connected to one of the OR circuits 80 and 81, and the output of the AND circuit 79 is connected to the timer 76.
．． 7, connected to the input of 77a. The outputs of the timers 76 and 77 are connected to the other inputs of the OR circuits 80 and 81, respectively.
The outputs of 81 are connected to the transistors 84 and 850 respectively. The relay coil /L/87.88 for attraction is connected to the collectors of the transistors 84 and 85 for opening and closing the relay contact 66.57.

The output of the timer 77a is connected to one input of the AND circuit 70a together with the output of the OR circuit To. Further, the output of the comparator 61 of the freezing room temperature control device 6o is connected to the other input of the OR circuit 82, and the output of the OR circuit 82 is connected to the pace of the transistor 86. The relay m point 65 is connected to the collector of the transistor 86.
A suction glue (Rekoi) V89 that opens and closes the is connected.

Here, the timer 75 is set to "High" once for the input.
(hereinafter simply referred to as 1H1) is input, it continues to output an "H" signal for a predetermined time t, and then switches to a "Low" signal (hereinafter simply referred to as "L"). Furthermore, while the *Hj signal is being input to the input, the timers 76 and 77 alternately output "H" and "Ll" signals for a predetermined period of time. For example, specifically, the output of the timer 76 is such that at the first time t1, the output rate of the "H" signal is 80%, and at the second time t2, the output rate is "H# times the signal". The output rate of the timer 77 is such that at the first time t11, the output rate of the H1 signal is 80%, and at the next time t2', the output rate of the H1 signal is 0%. It is configured. The operating time of the timers 76 and 77 is configured to be t1+t2=t1'+t2', and the predetermined time t of the timer 76 also serves as a time-safe function for the defrosting action.
Operating time of the timer 76.77 t1+t2=t1'
It is set to be sufficiently longer than +t2'. Furthermore,
The output of the timer 77a is normally 1H', and once "H" is input to the input, it continues to output "Hl" for a time t1=t1', and then outputs 1H for a time t2=t2'.
It is configured to be L1.

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 decreases and the output of the comparator 61 becomes @H1, so the transistor 62 is turned on and the relay coil/l is turned on. /63 becomes conductive. Therefore, the relay contact 54 is closed and the compressor 16 is operated. At the same time, the output of the OR circuit 82 is also "H", so the transistor 86 is turned on and the relay coil 89 becomes conductive.Therefore, the relay contact 66 is closed and the blower 18 is also operated, causing the freezer compartment to open. 13. Cold air is forced into the refrigerator compartment 14 and thawing compartment 15 for cooling.

Thereafter, when the freezer compartment 13 is cooled to a predetermined temperature, the output of the comparator 8, which has a large resistance value, of the temperature sensor 29 becomes "L". Therefore, the transistor 62 is turned off.
However, since the output of the OR circuit 82 also becomes 1L1, the transistor 86 also becomes 0FFI, and the power to the relay coils #63 and 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, -2
The temperature is maintained at 0℃).

Next, when the temperature of the refrigerator compartment 14 is higher than a predetermined value, the resistance value of the temperature detector 3o becomes small and the comparator 6
6 becomes "Hl", the transistor 66 turns on and the relay coil/L' 67 becomes conductive. Therefore, the relay contact 69 closes and the electromagnetic coil/L/21 is energized, and the damper of the damper thermo 19 is turned on. 24 is opened and refrigerator compartment 1
Cold air is introduced into the chamber 4 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 increases and the output of the comparator 65 becomes "Ll".
becomes. Therefore, the transistor 66 is turned off.

As a result, the current to the relay coil/l/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 until the inside of the refrigerator compartment 14 reaches a predetermined temperature (for example, 5
The temperature is maintained at ℃).

In addition, if the temperature of the thawing chamber 16 is higher than a predetermined value when not defrosting, the resistance value of the temperature detector 31 is reduced and the output of the comparator 69 becomes "H", so the OR circuit 70.AND The output of the circuit 70a becomes 1H', the transistor 71 is turned on, and the relay coil 72 becomes conductive.Therefore, the relay contact 68 is closed, the electromagnetic coil 21 is energized, and the damper thermometer 2o (-24 is opened). Cold air is introduced into the thawing chamber 16 to perform a cooling effect.

Thereafter, when the thawing chamber 15 is cooled to a predetermined temperature, the resistance value of the temperature detector 31 increases and the output of the comparator e9 becomes "Ll".Therefore, the output of the OR circuit 70 becomes "L". The output of AND circuit 70a is also @L J
(l) transistor 1 is OFF (j, relay coil) V72 is de-energized and relay contact 58 opens,
Power to the electromagnetic coil 21 is also cut off. Then, the damper 24 of the damper thermometer 2o is closed and the inside of the thawing chamber 16-5
The inflow of cold air is blocked. Thereafter, this action is repeated until the inside of the thawing chamber 15 reaches the third temperature zone between the freezing temperature and the refrigeration temperature suitable for preserving fresh foods, that is, the partial freezing temperature zone of approximately -3°C, as described above. Temperature control is maintained.

Next, we will discuss the action during thawing. First, the food to be thawed 46 to be thawed is placed on the thawing tray 44 and placed on the bottom plate 41 in the thawing chamber 16, and then the thawing switch 6 is turned on.
Insert 3. At the same time as the power is turned on, the timer 76 starts outputting a signal multiplied by "H", and one input of the AND circuits 78 and 79 becomes "H". At this time, the bottom plate 41 of the thawing chamber 16 is exposed to the low temperature 46 Foods to be thawed (for example -20℃)
The temperature decreases due to heat conduction with the thawing tray 44 on which the food is placed. That is, the temperature sensor 43 is in a sufficiently low temperature state.

Therefore, the output of the comparator 74 becomes Ll.
The signal inverted to 'H1' by the inverter 83 is input to the other input of the AND circuit 78. On the other hand, the "L" signal without passing through the inverter 83 is input to the AND circuit 9 as it is. The output of this useless AND circuit 78 is -1
゜Since the output of the AND circuit 79 becomes 1L", the timer 76.77 does not operate, and the output of the OR circuit 80.81 becomes "1L".
The transistors 84 and 85 turn on. Then, the relay coils 87 and 88 are energized, and the relay contact 5
6.57 is closed and far infrared heater 34, heating heater 4
2 is continuously energized.

When the thawing action progresses and the temperature sensor 43 rises to a predetermined temperature (for example, 30°C) (the time required for this is 70, and this period is defined as the first stage), the comparator 74 outputs an output. becomes “H”, and the inverter 83
The “L” signal is input to the AND circuit 78 via A
The output of the ND circuit 78 becomes "L". On the other hand, since the AND circuit 79 receives the "H" signal, the AND circuits 76 and 77 start alternately repeating and outputting the "Hl" and "L" signals at a predetermined intermittent rate. Transistor 8 via OR circuits 80 and 81 at the output rate
4.85 is 0N10FF.

Then, the power supply to the relay coils 87 and 88 is interrupted and the relay contacts 56 and 57 are intermittently opened and closed.

As a result, the far infrared heater 34 is continuously energized for a period of time t.
. At time 11 (this period is the second stage), the conduction rate is 80%.At the first time t2 (this period is the third stage), the conduction rate is 40ch, and the heat generation capacity is gradually increased as time passes. is controlled so that it decreases. Also, heater 4
2 is controlled so that the energization rate is 80% at the time t1' following the above continuous energization time 〇, and the energization rate is 0% and the heat generation capacity is decreased during the second time 12/. In this way, the food to be thawed 4
In the early stage of thawing when the temperature of 6 is low, the far infrared heater 34 and the heating heater 4 are turned on until the temperature of the temperature sensor 43 rises to a predetermined temperature.
Since both heaters 2 are continuously energized, even if the weight of the food to be thawed 45 varies, the amount of heat generated is adjusted to the degree of temperature rise of the temperature sensor 43 for a time appropriate for each weight. Since thawing can proceed rapidly under large conditions, the thawing time can be shortened. Thereafter, the heat generation capacity decreases stepwise with the passage of time, and thawing proceeds while suppressing the rise in surface temperature of the food to be thawed 46.

During thawing, radiant heating from the far-infrared heater 34 from the top surface of the food 46 to be thawed is performed evenly in combination with the reflection action of the three reflectors, and conductive heating by the heater 42 is simultaneously performed from the bottom surface. It turns out. here,
During heating by the far-infrared heater 34, far-infrared rays with a long wavelength of 6 μm or more are radiated to the food to be thawed 46, so that far-infrared rays are efficiently emitted from common foods that have an absorption wavelength band in the far-infrared wavelength region. It is absorbed and permeates relatively far into the interior of the food to be thawed 46, and thawing proceeds in a state where the temperature unevenness between the surface and the center does not become relatively large. Furthermore, in heating by the heater 42, the bottom surface of the food 46 to be thawed, 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 far-infrared heater 34 and the heating heater 42 are working on heating, the output of the timer 76 is "
During the first, second, and third stages in which the H" signal continues to be generated, the output of the OR circuit 82 becomes "H", and the transistor 86
turns ON, and relay coil/l/89 becomes conductive. Therefore, the relay contact 66 is closed and the blower 18 is forced to operate regardless of the output of the freezer temperature control device 60. On the other hand, the output of the timer 77a in the Jin-no-ma is:
In the first stage, the output of the comparator 74 becomes "L#" due to the output @L1" of the AND circuit 79 due to "L". In the subsequent second stage, when the output of the AND circuit 79 changes to "H", the output of the timer 77a changes to H1 in the second stage.
The third stage is 1L#. Therefore, the AND circuit 70
The output of a is also 'H' in the 1st and 2nd stages, and 'H' in the 3rd stage.
During this period, the transistor 71 becomes 0.N, ON,
It becomes OFF. That is, during thawing, the damper 24 of the damper thermometer 2o 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. The second stage is the open damper 2
Cold air forcedly ventilated by the blower 18 passes through the discharge duct 26 through the discharge port 51 and flows into the ventilation passage 50 in the upper part of the thawing chamber 15. The cold air that has flowed into the ventilation passage 50 is discharged downward from a large number of ventilation holes formed in the reflection plate 39.
The surface of the food 46 to be thawed is uniformly cooled. 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 control effect of gradually reducing the heat generation capacity of the far-infrared heater 34 and heating heater 42, as well as by further increasing the temperature of the surface area. As a result, thawing progresses with a small temperature difference between the center and surface areas and less uneven thawing. Then, the thawing progressed considerably,
After the end of the second stage (for example, when the center temperature of the food to be thawed 46 is around 15 degrees Celsius), the damper 24 of the damper thermostat 2Q is forcibly closed, and cold air is not introduced, and the heater does not generate heat. Defrosting progresses gradually with a small amount. 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 inside of the thawing chamber 15 is The residual 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 redundant operation of the compressor 16 can be avoided. In addition, the temperature characteristics and time chart of the food 45 to be thawed during thawing are shown in No. 6.
As shown in the figure.

Regarding 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 (e.g. approximately 30cm for a tuna with a weight of Boor and a thickness of 26cm). Since the reflecting plate 39 is exposed in the ventilation passage 60, the temperature of the reflecting plate 39 itself and surrounding members, which are originally quite high, is cooled and lowered, which is convenient from a safety standpoint.

This thawing action continues until time t. +t1+t2=
to+t1'+t2', that is, the first. Approximately 2. When the total time of the third stage has elapsed, the output of timer 76.7 is “L”.
'', the output from the timer 76 is input to the reset terminal of the timer 75, and the output of the timer 76 also becomes "L". Therefore, the transistors 84 and 85 are set to FF, respectively.
Then, the power to the relay coil/L/87°88 is cut off, the relay contacts 56 and 57 are opened, and the power to the far-infrared heater 34 and the heating heater 42 is cut off, and thawing is completed. At the same time, one input of the OR circuit 82 becomes "L", so that the forced operation state of the blower 18 is canceled. Further, since the output of the timer 77a returns to 'H1', one input of the AND circuit 70a becomes H1, and the forced blocking state of the damper 24 of the damper thermometer 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 46 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 the product is left as it is after thawing, it is kept cool at a partial freezing temperature range of approximately -3°C, which is suitable for preserving fish, local meat, etc., so the user can monitor the completion of thawing as usual. Thawing can be carried out with peace of mind 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.

Effects of the Invention As described above, the refrigerator with a defrosting chamber of the present invention provides the following effects.

(1) Efficient heating can be achieved from both sides: far-infrared radiant heating using a far-infrared heater from the top, and suspended conduction heating using a υ heating heater from the bottom, and the heat generation capacity of both heaters gradually decreases during thawing. Combined with the effect of far infrared rays penetrating into the interior of the food to be thawed, thawing with less temperature unevenness between the center and surface becomes possible.

(2) Until the temperature sensor installed on the bottom plate of the thawing chamber rises to a predetermined temperature, the far infrared rays and the heater are continuously energized, so even if the weight of the food to be thawed becomes small, the time suitable for each is maintained. The maximum dk heater allows for rapid heating and thawing in a short time.

(3) The first step during thawing. In the second step, the damper thermo for the thawing chamber is forcibly opened, and the blower is forced to operate continuously to cause cold air to descend and flow into the food to be thawed through the ventilation passage formed in the space on the back of the reflector. The surface of the food to be thawed is evenly cooled, temperature rise is further suppressed, and thawing with less unevenness can be achieved.

(4) 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.

(Suzuki) 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 also convenient for safety.

(6) After thawing, the inside of the thawing chamber is kept cool in the third temperature range between the freezing room temperature and the greenhouse temperature (for example, the partial freezing temperature range of approximately -3℃), so the remaining heat immediately after thawing is The temperature of the thawed food does not rise further, and even if it is left as is, its freshness is maintained at a temperature suitable for raw food such as fish meat, and the food can be used at any time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a thawing chamber of a refrigerator with a thawing chamber according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA/A of the thawing chamber of FIG.
Figure 3 is a vertical sectional view of the refrigerator with a thawing chamber shown in Figure 1, Figure 4 is an enlarged sectional view of the damper thermometer installed at the entrance of the thawing chamber shown in Figure 1, and Figure 6 is Fig. 3 is an electric circuit and control circuit diagram of a refrigerator with a thawing chamber, Fig. 6 is a time chart during thawing and a temperature characteristic diagram of food to be thawed, Fig. 7 is a perspective view of a thawing box showing a conventional example, FIG. 8 is a sectional view taken along the line B-IF of the thawing box shown in FIG. 7. 13... Freezer room, 14... Refrigerator room, 1
5... Thawing chamber, 16... Compressor, 17
...Cooler, 18...Blower, 2o.
... Damper thermo, 34 ... Far infrared heater, 39 ... Reflection plate, 40 ... Warm air hole, 41 ... Bottom plate, 42... Heater, 43... Temperature detector, 44...
- Thawing dish, 46...Food to be thawed, 49...
...door, 5o...ventilation duct, 73...defrosting control device.

Claims (1)

[Claims] A freezing room, a refrigerator room, a thawing room whose outer periphery is surrounded by a heat insulating material and a front opening with a door that can be opened and closed, a compressor and a cooler for the refrigeration cycle, and a refrigeration cycle compressor and a cooler, and the air cooled by the cooler is transferred to the freezer. A blower for forcing air into the room, refrigerator, and thawing chamber; a far-infrared heater provided at the top of the thawing chamber; a metal bottom plate provided at the bottom of the thawing chamber; and a heat conductive device on the back side of the bottom plate. a temperature sensor that is thermally conductively adhered to approximately the center of the back surface of the bottom plate; and a metal reflecting plate that covers the top surface of the far-infrared heater in a dome shape;
A thawing tray on which food to be thawed is placed and is thermally conductive and removably installed on the bottom plate, and a damper thermostat installed at the cold air inlet of the thawing chamber to adjust the amount of cold air inflow by electrical input. a ventilation passage formed in the upper space on the back surface of the reflector plate and communicating with the damper thermo, a large number of ventilation holes provided in the reflection plate to communicate the ventilation passage with the inside of the thawing chamber, and the blower during thawing. Forced operation and defrosting time 3
The far infrared heater and heating heater are continuously energized with the time from the start of thawing until the temperature of the temperature sensor rises to a predetermined temperature as the first stage, and the second and third stages thereafter. In the first and second stages, the damper thermo is forced to open, and in the third stage, the damper thermo is forced to open. A refrigerator with a thawing chamber, comprising a thawing control device that is closed and maintains the thawing chamber in a third temperature range between a refrigerating temperature and a freezing temperature when not thawing.