JPH05141858A - Refrigerator with thawing chamber - Google Patents

Abstract

PURPOSE:To reduce unevenness in thawing of frozen foods and complete thawing in a short time in the method of control of a thawing heater for foods in the use of a refrigerator with a thawing chamber. CONSTITUTION:On the basis of changes in temperature of a temperature detector 43 the control is carried out by the use of a far infrared heater 36, heater 42, fan 18, thawing chamber damper thermostat 20, comparison circuits 74, 74', timer 75, and counters 76, 77.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator with a thawing chamber for thawing frozen food.

[0002]

2. Description of the Related Art Conventionally, an example of using a heater for thawing frozen foods is known. For example, Japanese Patent Publication Sho 48-
This is the example shown in Japanese Patent No. 25414, which will be described below with reference to FIGS. 7 and 8.

Reference numeral 1 denotes a thawing box, which is an outer box 2 formed of a metal or a synthetic resin in a box shape, and an aluminum box having a good thermal conductivity provided inside the outer box 2 with an appropriate gap. The inner box 3 is made of metal. Reference numeral 4 is a linear heater, and the bottom portion of the thawing box 1 is sparsely and the top portion of the thawing box 1 is dense so as to be in thermal conductive contact with the inner box 3 by an aluminum foil 5. Reference numeral 6 is a heat insulating material interposed between the outer box 2 and the aluminum foil 5.

In such a structure, when the food to be thawed 7 is placed on the bottom surface of the thaw 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 is almost evenly coated. The feature is that the thawed food 7 is heated and thawed.

[0005]

However, with such a configuration, although heat can be transferred from the bottom part of the thawing box 1 to the bottom part of the food 7 to be thawed by heat conduction, the bottom part can be thawed. The effect of radiant heat from the top and side surfaces of the box 1 to the food to be defrosted 7 is almost zero because the wavelength of the heat ray from the heater 4 through the inner box 3 is in the near-infrared region of 5 μm or less. The heating is carried out only by the heat transfer by the convection of the warmed air in 1. Therefore, the food to be thawed 7
The thawing unevenness between the central part and the surface part of the meat tends to be large, and it takes a long time to thaw, and if the food is left as it is after thawing, the ambient temperature is high especially for raw food such as fish meat. Since there is a change in quality, it is necessary for the user to monitor and process the completion of thawing, which is a drawback that the product cannot be used safely.

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

[0007]

In order to solve the above-mentioned problems, a refrigerator with a thawing chamber according to the present invention comprises a far-infrared heater on the upper surface of the thawing chamber and a reflector that covers the upper portion in a dome shape, a heater on the bottom surface and a temperature. By providing a bottom plate with the detector closely attached,
A thaw plate on which the food to be thawed is placed is installed on the bottom plate. An air passage is formed in the back space of the reflection plate to communicate with a damper thermostat for adjusting the amount of cold air flowing in the cold air inlet of the thawing chamber, and a large number of air holes are formed in the reflection plate. In contrast to such a configuration, the damper thermo is forcibly opened during the thawing, the blower is forcibly operated, and the temperature of the temperature detector on the bottom plate is set to the second temperature from the start of the thawing.
The far-infrared heater and the heating heater are continuously energized until the temperature reaches the second predetermined temperature, and when the temperature of the temperature detector rises to the second predetermined temperature, the temperature of the temperature detector rises to the first and second predetermined temperatures. A thaw control device is provided to select a predetermined energization pattern for energization according to the time difference required for the operation, and to maintain the thaw chamber in the third temperature zone between the refrigerating temperature and the freezing temperature when not thawing. Is.

Also, instead of the time difference,
A temperature change degree of the temperature detector in a fixed minute time near the second two temperatures, and a temperature gradient with respect to an average time obtained from both the time difference and the temperature change degree;
As the temperature change degree, an average value of both values calculated at the first and second predetermined temperatures is adopted.

[0009]

According to the present invention, the far-infrared heater directly radiates far-infrared rays from the top and side surfaces of the food to be thawed and indirectly radiates through the reflecting plate, and heat transfer from the heater on the bottom surface is performed by the above-described structure. Is performed and heat is absorbed. Further, both heaters are continuously energized and the temperature of the food to be thawed rises rapidly until the temperature detector on the bottom surface rises to a predetermined temperature. After that, the energization rate of both heaters is determined by the time difference between the two temperatures which is relatively representative of the defrosting state, so that the appropriate heating state is selected for foods of various weights and the defrosting proceeds. Cold air is evenly supplied to the food to be thawed through a large number of ventilation holes formed in the upper surface of the reflecting plate via the damper thermostat, thereby suppressing an increase in the temperature of the food surface. Further, after the thawing is completed, the temperature of the food is automatically maintained in the third temperature zone between the refrigerating temperature and the freezing temperature by the temperature control action of the damper thermostat and kept cold.

Further, instead of the time difference between the two temperatures,
Even if the temperature change degree of the temperature detector in a fixed minute time around the two temperatures is adopted, the same effect as above can be obtained.

Further, if a temperature gradient with respect to an average time obtained from both the time difference and the temperature change degree is adopted, a more reliable operation can be obtained.

Further, the temperature change degree is set to the first and second values.
If you adopt the average value of both values calculated at the predetermined temperature of,
The same highly reliable operation as described above can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator with a thawing chamber according to an embodiment of the present invention will be described below with reference to FIGS.

A refrigerator body 8 is composed of an outer box 9, an inner box 10 and a heat insulating material 11 filled between the boxes 9 and 10. Reference numeral 12 is a partition wall that partitions the interior of the refrigerator body 8 into upper and lower parts. A freezer compartment 13 is formed in an upper portion of the partition wall 12, and a refrigerating compartment 14 is formed in a lower portion. Reference numeral 15 denotes a thawing chamber provided in a section above the refrigerating chamber 14. Reference numeral 16 is a compressor of the refrigeration cycle provided at the rear of the bottom of the refrigerator main body 8, and 17 is a cooler housed in the rear surface of the freezing chamber 13. Reference numeral 18 denotes a blower for forcing the cool air cooled by the cooler 17 into the freezing compartment 13, the refrigerating compartment 14, and the defrosting compartment 15, and 19 and 20 denote the refrigerating compartment 14 and the defrosting compartment 15.
Is a damper thermostat which is installed at the inlet of the dehumidifying chamber 15 and regulates the inflow amount of cold air by an electric input. The damper thermostat 20 for the defrosting chamber 15 will be explained as an example. 21 is an electromagnetic coil and 22 is an inner core of the electromagnetic coil 21. The part 23 moves up and down depending on the presence or absence of electromagnetic action, 23 is a rod joined to the plunger 22, 24 is a damper that opens and closes the cold air passage, and the rod 23 is moved by electromagnetic action when the electromagnetic coil 21 is energized. When the damper 24 is pushed up to open and the power supply is cut off, the rod 23 drops downward so that the damper 24 is closed. Although not shown, the electromagnetic coil of the damper thermostat 19 for the refrigerating room having the same structure is not shown for convenience of the following description.
1'and a damper 24 '.

Reference numerals 25 and 26 denote discharge ducts for guiding the cool air from the blower 18 to the refrigerating chamber 14 and the thawing chamber 15, 27,
Reference numeral 28 is a suction duct for returning cold air, which has cooled the refrigerating chamber 14 and the thawing chamber 15, to the cooler 17, respectively.
Further, 29, 30 and 31 are the freezing room 13 and the refrigerating room 1, respectively.
4. A temperature detector for detecting the temperature inside the thawing chamber 15.

Next, the detailed structure of the thawing chamber 15 will be described. 32 is a synthetic resin outer box, 33 is the outer box 32
It is a heat insulating material that is installed on the inner surface of and surrounds the outer circumference. Reference numeral 34 is a far-infrared heater provided in the upper portion of the thawing chamber 15. The surface of a glass tube 36 enclosing the heater wire 35 is baked and coated with a ceramic paint layer 37 containing silicon or the like as a main component to a thickness of about 5 μm.
It is configured to effectively radiate far infrared rays of m or more.
The far-infrared heater 34 is suspended from a reflector plate 39 made of metal such as aluminum and formed in a dome shape via a holder 38 made of synthetic resin having high heat resistance. Further, the reflecting plate 39 is formed integrally with both side walls inside the thawing chamber 15 and the inner box part constituting the back wall, and a large number of ventilation holes 40 are formed in the flat surface portions on both sides of the top dome. ing. Next, 41 is a bottom plate made of metal such as aluminum, 42 is a linear heater which is thermally conductively fixed to the back surface of the bottom plate 41 with aluminum foil or the like, and 43 is the bottom plate 41. This is a temperature detector that is heat conductively attached to the vicinity of the center of the back surface. Reference numeral 44 denotes a thaw plate that is detachably installed on the bottom plate 41, and is composed of a plate 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 circumference. .. Reference numeral 48 is a protective net for preventing burns, which is fixedly installed below the reflection plate 39 at regular intervals, and 49 is a door for opening and closing the front opening of the thawing chamber 15. Reference numeral 50 denotes an air passage formed in the back space of the reflection plate 39, which communicates with the damper thermostat 20 through a discharge port 51. Reference numeral 52 is a suction port formed in the inner wall of the thawing chamber 15 and communicates with the suction duct 28. Reference numeral 53 is a thawing switch provided on the front surface of the outer shell of the refrigerator body 8.

Next, the electric circuit and the control circuit will be described. The compressor 16 receives the blower 18 via the relay contact 54.
Are connected to power sources via relay contacts 55, respectively.
The far infrared heater 34 is connected to a power source via a relay contact 56, and the heating heater 42 is connected to a power source via a relay contact 57. Moreover, the electromagnetic coil 2 of the damper thermo for the defrosting room
1. The electromagnetic coil 21 of the damper thermostat for the refrigerator compartment is connected to the power source via relay contacts 58 and 59, respectively.

Reference numeral 60 denotes a freezing room temperature control device, which is provided with a temperature detector 29 such as a thermistor, resistors R ₁ , R ₂ and R ₃ , a comparison circuit having a comparator 61, a transistor 62 and a relay coil 63. The output of the comparator 61 is connected to the base of the transistor 62. or,
The collector coil of the transistor 62 is connected to the relay coil 63 for attraction which opens and closes the relay contact 54. Reference numeral 64 denotes a refrigerating room temperature control device, which includes a temperature detector 30 such as a thermistor, resistors R ₄ , R ₅ and R ₆ , and a comparator 65.
Comparing circuit with, transistor 66, relay coil 6
7, the output of the comparator 65 is connected to the base of the transistor 66. The collector coil of the transistor 66 is connected to the relay coil 67 for attracting and closing the relay contact 59. 68
Is a defrosting room temperature control device, which is a temperature detector 3 such as a thermistor.
1, a resistor R ₇ , R ₈ , R ₉ , a comparison circuit including a comparator 69, an OR circuit 70, a transistor 71, and a relay coil 72 are provided, and the temperature of the thawing chamber 15 is approximately −3 ° C. during normal cooling. The resistance is configured so as to be controlled to the partial freezing temperature of. The output of the comparator 69 is connected to one input of the OR circuit 70.
The output of the OR circuit 70 is connected to the base of the transistor 71, and the collector of the transistor 71 is connected to the relay coil 72 for attraction that opens and closes the relay contact 58.

Reference numeral 73 denotes a thawing control device, which is a temperature detector 43 closely attached to the bottom plate 41 of the thawing chamber 15 and resistors R ₁₀ and R.
₁₁ , R ₁₂ , R ₁₁ ′, R ₁₂ ′, comparators 74, 74 ′
Comparing circuit and timer 75, counters 76, 7
7, AND circuits 78, 79, 79 ', OR circuits 80, 8
1, 82, the OR circuit 70, the inverter 83, the transistors 84, 85, 86, the relay coils 87, 88, 8
9 and the defrosting switch 53.

The output of the decompression switch 53 is connected to the input of the timer 75, and the output of the timer 75 is the AND circuits 78, 79 and the OR circuit 7.
0 and 82 are connected to one input and timers 76 and 77 are connected to inputs 76b and 77b. The output of the comparator 74 is connected to the other input of the AND circuit 78 via the inverter 83, and at the same time the AN is connected.
It is connected to the other input of the D circuit 79. The A
The output of the ND circuit 78 is connected to one of the OR circuits 80 and 81, the output of the AND circuit 79 is connected to one of the inputs of the counters 76 and 77, and at the same time, the output of the comparator 74 'and the output of the comparator 74'. AND circuit 79 '
Of the AND circuit 79 ', and the output of the AND circuit 79' is connected to the other input of the counters 76 and 77. The outputs of the counters 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 connected to the bases of the transistors 84 and 85, respectively. .. The collectors of the transistors 84 and 85 have the relay coil 8 for attraction for opening and closing the relay contacts 56 and 57.
7,88 are connected. Further, the output of the comparator 61 of the freezer compartment temperature control device 60 is connected to the other input of the OR circuit 82, and the OR circuit 8
The output of 2 is connected to the base of the transistor 86. The collector of the transistor 86 has a relay coil 89 for attraction that opens and closes the relay contact 55.
Are connected.

Here, the timer 75 once receives an input.
When a "High" (hereinafter simply referred to as "H") signal is input
The "H" signal is continuously output for a predetermined time t, and then "L"
Switch to the ow "(hereinafter simply referred to as" L ") signal
It is configured. Also, the counters 76 and 77 are
When the "H" signal is input to the input of, counting starts,
When the "H" signal is input to the other input, the count is
Finished and determined in advance according to the count amount
Outputs "H" and "L" signal patterns respectively
It is configured as follows. For example, specifically, the counter
-76 output is the first time t₁Is the output rate of the "H" signal
Is 80%, next time t₂Then, the output rate of the "H" signal is 4
The output of the counter 77 is configured to be 0%.
First time t₁'Has an output rate of "H" signal of 80%,
Time t₂′ Is set so that the output rate of the “H” signal is 0%.
Is made. When the counters 76 and 77 are operating
Is t ₁+ T₂= T₁′ + T₂'Is configured such that
The predetermined time t of the timer 75 is a time-safe thawing action.
The counters 76, 7 including the role of
7 operation time t₁+ T₂= T₁′ + T₂′ Is much longer than
Is set.

In such a structure, 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 that the transistor 62 is turned on and the relay is turned on. The coil 63 becomes conductive. Therefore, the relay contact 54 is closed and the compressor 16 is operated. At the same time, since the output of the OR circuit 82 is also "H", the transistor 86 is turned on and the relay coil 89 is turned on. Therefore, the relay contact 55
Closed, the blower 18 is also operated, and the freezer compartment 13 and the refrigerator compartment 1
4. Forced ventilation of cold air to the thawing chamber 15 for cooling. After that, 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 off
Further, since the output of the OR circuit 82 also becomes "L", the transistor 86 is also turned off and the power supply to the relay coils 63 and 89 is cut off. For this reason, the compressor 16 and the blower 18 in which the relay contacts 54 and 55 are both opened are stopped. After that, this operation is repeated and the inside of the freezer compartment 13 reaches a predetermined temperature (for example, -2).
The temperature is maintained at 0 ° C.

Next, when the temperature of the refrigerating compartment 14 is higher than a predetermined value, the resistance value of the temperature detector 30 is small and the output of the comparator 65 becomes "H", so that the transistor 66 is turned on and the relay coil is turned on. 67 becomes conductive. Therefore, the relay contact 59 is closed to energize the electromagnetic coil 21 ', the damper 24' of the damper thermostat 19 is opened, and cool air is introduced into the refrigerating chamber 14 to perform a cooling action. After that, when the refrigerating chamber 14 is cooled to a predetermined temperature, the resistance value of the temperature detector 30 increases and the output of the comparator 65 becomes "L". Therefore, the transistor 66 is OF
Then, the relay coil 67 is de-energized, the relay contact 59 is opened, and the electromagnetic coil 21 'is de-energized.
Then, the damper 24 'of the damper thermostat 19 is closed to prevent the cold air from flowing into the refrigerating chamber 14. After that, this operation is repeated and the inside of the refrigerating chamber 14 has a predetermined temperature (for example, 5
Temperature control is maintained at (℃).

When the temperature of the thawing chamber 15 is higher than the predetermined value when not thawing, the resistance value of the temperature detector 31 is small and the output of the comparator 69 becomes "H". The output becomes "H", the transistor 71 turns on, and the relay coil 72 becomes conductive. Therefore, the relay contact 58 is closed, the electromagnetic coil 21 is energized, the damper 24 of the damper thermostat 20 is opened, and cold air is introduced into the thawing chamber 15 to perform a cooling action. After that, 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 69 becomes "L". Therefore, the output of the OR circuit 70 becomes "L", the transistor 71 is turned off, the power supply to the relay coil 72 is cut off, and the relay contact 58 is opened.
The power supply to the electromagnetic coil 21 is also cut off. Then, the damper 24 of the damper thermostat 20 is closed to prevent cold air from flowing into the thawing chamber 15. Thereafter, by repeating this operation, the temperature inside the thawing chamber 15 is adjusted to the third temperature zone between the freezing temperature and the refrigerating temperature, which is suitable for storing fresh food, that is, the partial freezing temperature zone of about -3 ° C, as described above. Maintained.

Next, the operation at the time of thawing will be described. First,
The food to be thawed 45 to be thawed is placed on the thaw tray 44, placed on the bottom plate 41 in the thaw chamber 15, and then the thaw switch 53 is turned on. Timer 75 when turned on
Starts outputting the "H" signal, and one input of the AND circuits 78 and 79 becomes "H". At this time, the temperature of the bottom plate 41 of the thawing chamber 15 is lowered by heat conduction with the thawing dish 44 on which the food to be thawed 45 having a low temperature (for example, −20 ° C.) in a frozen state is placed. That is, the temperature detector 43 is in a sufficiently low temperature state. Therefore, the output of the comparator 74 is "L".
The signal inverted to "H" by the inverter 83 is input to the other input of the AND circuit 78. On the other hand, the “L” signal that does not pass through the inverter 83 is directly input to the AND circuit 79. Therefore, the output of the AND circuit 78 is "H" and the output of the AND circuit 79 is "L".
Therefore, the counters 76 and 77 do not operate, the outputs of the OR circuits 80 and 81 become "H", and the transistor 8
4,85 turn 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 energized continuously. And
When the thawing action progresses and the temperature detector 43 rises to a predetermined temperature (for example, 30 ° C.) set in advance (the time required for this is t ₀ ), the output of the comparator 74 becomes “H”, and the output is passed through the inverter 83. Then, the "L" signal is input to the AND circuit 78, and the output of the AND circuit 78 becomes "L". On the other hand, since the "H" signal is input to the inputs 76a and 77a of the AND circuit 79, the counters 76 and 77 alternately and repeatedly output the "H" and "L" signals according to a predetermined energization pattern. For this reason, the transistors 84 and 8 are connected through the OR circuits 80 and 81 at a corresponding intermittent output rate.
5 turns ON / OFF. And the relay coils 87, 8
8 is intermittently energized to open / close the relay contacts 56 and 57 intermittently. As a result, in the far-infrared heater 34, the heat generation capacity gradually decreases with the lapse of time, that is, the time t ₁ following the time t _{0 of} continuous energization is 80% at the time t ₁ and the next time t ₂ is 40% at the time t _2. To be controlled. Also heater 4
2 is the time t _{0 of the} continuous energization and the time t ₁ ′ is the energization rate 8
0%, and the next time t ₂ ′ is controlled so that the heat generation capacity is reduced to 0%. Thus, in the initial stage of thawing when the temperature of the food to be defrosted 45 is low, both the far infrared heater 34 and the heater 42 are continuously energized until the temperature of the temperature detector 43 rises to a predetermined temperature. Even if the weight of the temperature detector changes variously, the thawing time can be shortened because the thawing time can be promoted without excess or deficiency for a time suitable for each weight depending on the degree of temperature rise of the temperature detector 43. Then, since the heat generation capacity gradually decreases with the lapse of time, the thawing proceeds while suppressing an increase in the surface temperature of the food to be defrosted 45. During thawing, radiant heating from the far-infrared heater 34 is uniformly performed on the food to be defrosted 45 from the upper surface in combination with the reflecting action of the reflecting plate 39, and heat transfer heating by the heating heater 42 is simultaneously performed from the bottom surface. It will be. Here, when the far infrared heater 34 is heated, far infrared rays having a long wavelength of 5 μm or more are radiated to the food to be defrosted 45, so that it is efficient in general foods having an absorption wavelength band in the far infrared wavelength range. Far-infrared rays are absorbed, and food to be thawed 45
The thawing proceeds in a state where the temperature of the surface portion and the central portion does not become relatively large by penetrating relatively to the inside. or,
In the heating by the heater 42, the bottom portion of the food to be defrosted 45, which cannot be sufficiently heated by the far infrared heater 34, can be thawed by heat transfer heating via the thaw plate 44.

On the other hand, at the same time as the heating operation by the far infrared heater 34 and the heater 42, the outputs of the OR circuits 70 and 82 are also "H" during the defrosting, that is, while the output of the timer 75 continues to generate the "H" signal. And transistor 71,
89 is turned on, and the relay coils 72 and 89 are conducted. Therefore, the relay contacts 58 and 55 are closed and the electromagnetic coil 21 is energized regardless of the output of the thaw chamber temperature control device 68, and the damper 2 of the thaw chamber damper thermostat 20.
4 is forcibly opened, and the blower 18 is forcibly operated regardless of the output of the freezer compartment temperature control device 60.
The cool air forcedly ventilated by the blower 18 through the damper 24 opened in this way is discharged through the discharge duct 26 to the discharge port 5
1 flows into the ventilation passage 50 above the thawing chamber 15. The cool air that has flowed into the ventilation passage 50 is discharged downward through a large number of ventilation holes formed in the reflection plate 39, and evenly cools the surface of the food to be defrosted 45. Due to this action, the food to be defrosted 45 mainly has a far-infrared radiation effect of the far-infrared heater 34 and a control effect of gradually decreasing the heat generation capacities of the far-infrared heater 34 and the heating heater 42, and further increases the temperature of the surface portion. As a result, thawing with a small temperature difference between the central portion and the surface portion and less thawing unevenness can be realized (the temperature characteristics and time chart of the food to be thawed 45 during thawing are shown in FIG. 6).

With respect to the thawing time, a relatively short time thawing (for example, a weight of 500 g and a thickness of 25 mm of tuna is about 30 min) can be achieved by the internal penetration effect of far infrared rays and continuous heating control at the beginning of thawing. Board 39 is ventilation path 5
Since it is exposed in 0, the reflector plate 3 has a high temperature originally.
The temperature of 9 itself and peripheral members is cooled and lowered, which is convenient for safety. After the cooling action of the cold air flowing into the thawing chamber 15, it is recovered to the cooler 17 through the suction duct 28 from the suction port 52 opened on the inner surface.

Such a thawing action proceeds and time t ₀ +
When t ₁ + t ₂ = t ₀ + t ₁ ′ + t ₂ ′ elapses, the outputs of the counters 76 and 77 become “L”, and the output of the timer 75 is also input to the reset terminal of the timer 75 to be “L”. Becomes Therefore, the transistors 84 and 85 are turned off, and the relay coils 87 and 88 are turned off.
Is cut off, relay contacts 56 and 57 are opened, and far infrared heater 34 and heating heater 42 are cut off and thawing is completed. At the same time, the OR circuits 70 and 82
Since one of the inputs is "L", the forced operation state of the blower 18 and the forced open state of the damper 24 of the defrosting chamber damper thermostat 20 are released.

After completion of the thawing, the temperature inside the thawing chamber 15 is controlled based on the temperature detected by the temperature detector 31 as in the case of normal cooling. Therefore, the defrosted food 45 after defrosting is about −
It is immediately cooled so as to stabilize in the partial freezing temperature zone of 3 ° C, and the temperature does not rise further due to residual heat. And even if it is left as it is after thawing, it is kept cold at a partial freezing temperature zone of about -3 ° C suitable for preservation of raw materials such as fish and meat, so the user monitors the end of thawing as before. Therefore, the food can be thawed without anxiety, and the food to be defrosted 45 can be used at any time after the end of the thawing, which is extremely convenient.

Further, instead of the time difference between the two temperatures,
The temperature change degree of the temperature detector 43 in a fixed minute time near the two temperatures, and the temperature gradient with respect to an average time obtained from both the time difference and the temperature change degree, and the temperature If an average value of both the values calculated at the first and second predetermined temperatures is used as the degree of change, it is possible to prevent an erroneous determination due to a measurement error.

[0031]

As described above, according to the refrigerator with the thawing chamber of the present invention, the following effects can be obtained.

(1) Efficient heating is possible from both of the far infrared radiant heating by the far infrared heater from the top surface and the heat conduction heating by the heater from the bottom surface. Moreover, during thawing, the thawing process is evaluated during thawing. By optimally setting the energization pattern of both the heaters, the temperature unevenness of the central portion and the surface portion can be reduced together with the penetration effect of far infrared rays into the food to be thawed, and the weight of the food to be thawed can be reduced. Even if there is a change, rapid heating can be performed with the optimum heater capacity for a time suitable for each, and thawing can be completed in a short time in an appropriate thawing state.

(2) As an evaluation of the thawing process, the
In addition to the time difference between the temperatures, the temperature change degree of the temperature detector in a fixed minute time around the two temperatures, and the temperature gradient with respect to the average time obtained from both the time difference and the temperature change degree. In addition, the temperature change degree is set to the first and second
If you adopt the average value of both values calculated at the predetermined temperature of,
The accuracy of evaluation of the thawed state is improved, and the thawed state becomes more homogeneous and excellent in a short time.

[Brief description of drawings]

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.

FIG. 2 is a sectional view taken along the line AA ′ of FIG.

FIG. 3 is a vertical sectional view of the refrigerator with the thawing chamber.

FIG. 4 is an enlarged sectional view of a damper thermostat installed at the entrance of the thawing chamber.

[Fig. 5] Electric circuit and control circuit diagram of the refrigerator with the same 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 conventional thawing box.

8 is a sectional view taken along line BB ′ of FIG.

[Explanation of symbols]

 13 Freezing Room 14 Refrigerating Room 15 Defrosting Room 16 Compression Room 17 Cooler 18 Blower 20 Damper Thermo 34 Far Infrared Heater 39 Reflector 40 40 Vent 41 Bottom Plate 42 Heating Heater 43 Temperature Detector 44 Thaw Plate 45 Thawed Food 49 Door 50 Ventilation path 73 Thaw control device

Claims (4)

[Claims] 1. A freezing chamber, a refrigerating chamber, a defrosting chamber having an outer periphery surrounded by a heat insulating material and having a front opening provided with an openable / closable door, a compressor and a cooler of a refrigeration cycle, and cooled by the cooler. A blower for forcedly ventilating the freezing chamber, the refrigerating chamber, and the thawing chamber, a far-infrared heater provided at the upper portion of the thawing chamber, a metal bottom plate provided at the bottom of the thawing chamber, and the bottom plate Heater that is heat conductively attached to the back surface of the bottom plate, a temperature detector that is heat conductively attached to the center of the back surface of the bottom plate, and a metallic reflection that covers the upper surface of the far infrared heater in a dome shape. A plate, a thawing plate on which the food to be thawed is placed on the bottom plate in a thermally conductive and detachable manner, and an electric input provided at the cold air inlet of the thawing chamber controls the inflow amount of cold air. The damper thermo that communicates with the damper thermo, Ventilation path formed in the upper space, a large number of ventilation holes provided in the reflection plate to communicate with the ventilation path and the thawing chamber, and during thawing, the damper thermostat is forcibly opened, and the blower is forcibly operated and thawed. During the time from the start until the temperature of the temperature detector rises to the second predetermined temperature, the far infrared heater and the heating heater are continuously energized, and when the temperature of the temperature detector rises to the second predetermined temperature, Depending on the time difference required for the temperature of the temperature detector to rise to the first and second predetermined temperatures, the energizing pattern is selected to energize, and when not thawing, the thawing chamber, the refrigerating temperature and the freezing temperature are selected. A refrigerator with a thawing chamber, which comprises a thawing control device for maintaining the temperature in the third temperature range between. 2. The far infrared heater and the heating heater are continuously energized during the time from the start of thawing until the temperature of the temperature detector rises to the first predetermined temperature, and at that time, the temperature of the temperature detector is maintained for a certain minute time. The refrigerator with a thawing chamber according to claim 1, wherein the energizing pattern is selected based on the degree of change to energize. 3. A difference between the time required for the temperature of the temperature detector to rise to the first and second predetermined temperatures and a certain minute time when the temperature of the temperature detector rises to the first predetermined temperature. The refrigerator with a defrosting chamber according to claim 1, wherein energization is performed by selecting an energization pattern from a temperature gradient with respect to an average time obtained from both values of the temperature change degree of the temperature detector. 4. An energization pattern is selected according to an average value of both temperature change degrees of the temperature detector in a fixed minute time each time the temperature of the temperature detector rises to the first and second predetermined temperatures. The refrigerator with a thawing chamber according to claim 1, wherein electricity is supplied by electricity.