JPH03140785A - 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 heater is conducted continuously from the starting of defrosting to a time when the temperature of a bottom plate is risen to a predetermined temperature and when the same temperature has risen to the predetermined temperature, the rate of conduction of the heater is reduced for a period of time obtained by multiplying a time, required for rising to the predetermined temperature, by a first magnification and, thereafter, the rate of conduction of the heater is reduced further for a time obtained by multiplying the time, required for rising to the predetermined temperature, by a second magnification. CONSTITUTION:Foods 45 to be defrosted are put on a defrosting tray 44 and the tray 44 is arranged on a bottom plate 41 in a defrosting chamber 15, then, a defrosting switch is thown. Then, a far-infrared ray heater 34 and a heater 42 are conducted continuously. When the defrosting operation is advanced and a temperature, detected by a temperature detector 43, has risen to a predetermined temperature, the heat generating capacity of the far-infrared heater 34 is reduced to the rate of conduction of 80% for a time (t1) after the continuous conduction time (to), then, the rate of conduction is reduced to 40% for a successive time (t2) and, thus, the rate of conduction is reduced stepwisely in accordance with the elapse of time. On the other hand, the rate of conduction of the heater 42 is 80% for a time (t1') after the continuous conduction time (to) and the same rate is reduced to 0% in a successive time (t2').

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, examples of using a heater to defrost frozen foods have been known. For example, an example is shown in Japanese Patent Publication No. 48-25414, 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 6 so that the bottom surface of the thawing box 1 is sparse and the top surface is densely packed.

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

Problems to be Solved by the Invention However, with such a configuration, heat is transmitted from the bottom of the thawing box 1 to the bottom of the food to be thawed 7 by thermal conduction, and although it is possible to thaw the bottom of the food 7, the thawing box 1 The effect of radiant heat on the food to be thawed 7 from the top and side surfaces is almost negligible because the heat ray wavelength from the heater 4 through the inner box 3 is in the near-far infrared range of 6 μm or less, Heating occurs only by heat transfer by convection of warmed air. For this reason, there are disadvantages that the unevenness of thawing between the center and surface of the food to be thawed 7 tends to become large, and that it takes a long time to thaw. Since deterioration occurs due to the high ambient temperature, the user has to monitor the completion of defrosting before processing, which has the disadvantage that it cannot be used with confidence.

The present invention solves the above-mentioned problems, and aims to provide a thawing chamber, especially in a refrigerator, that is less uneven in thawing and can be thawed 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, during thawing, the damper thermo is forced open and the blower is forced into operation, and the far-infrared heater and heating heater are turned on from the start of thawing until the temperature of the temperature sensor on the bottom plate rises to a predetermined temperature. is continuously energized, and when the temperature of the temperature sensor rises to a predetermined temperature, the energization rate to both heaters is set to the time required for the temperature of the temperature sensor to rise to the predetermined temperature multiplied by the first constant multiplier. After that, the second
A thawing control device is provided which further reduces the energization rate to both heaters for a certain time multiplied by a certain factor of , and maintains the thawing chamber in a third temperature range between the refrigeration temperature and the freezing temperature when not thawing.

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.

Further, until 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 increases rapidly. The energization rate of the rear heater is reduced to two levels and the energization time is set until the temperature of the temperature sensor rises to a predetermined temperature. Cold air is evenly supplied to the food to be thawed through the many ventilation holes formed on the upper surface of the reflector via the damper 7, thereby suppressing the temperature rise on the food surface. Further, after thawing is completed, the temperature of the food is automatically maintained at a 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 itself and the outer box 9. Inner box 1o and both boxes 9.
It is composed of a heat insulating material 11 filled between 10 and 10.

12 is a partition wall υ 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. Reference numeral 18 supplies the cold air cooled by the cooler 17 to the freezer compartment 13, refrigerator compartment 14. A blower for forcing air into the thawing chamber 15, 1
Damper thermos 9 and 20 are provided at the entrances of the refrigerator compartment 14 and the thawing compartment 16 to adjust the amount of cold air flowing in through electrical input.The structure of the damper thermos 2o for the thawing compartment 16 will be explained as an example. 21 is an electromagnetic coil; 22 is a plunger that moves the inner core of the electromagnetic coil 1v21 up and down depending on the presence or absence of electromagnetic action; 23 is a rod connected to the plunger 22; 24 is a damper that opens and closes the cold air passage; When the coil A/21 is energized, the rod 23 is pushed up by electromagnetic action and the damper 24 is opened, and when the energization is cut off, the rod 23 falls downward and the damper 24 is closed. has been done. Although not shown in the drawings, for convenience of later explanation, the electromagnetic coil of the damper thermometer 19 for the refrigerator compartment having the same structure will be referred to as 21' and the damper thermometer 24'.

2ES, 26 sends cold air from the blower 18 to the refrigerator compartment 14. Discharge ducts 27 and 28 leading to the thawing chamber 16 are respectively connected to the refrigerating chamber 14. This is a suction duct for returning the cold air that has cooled the inside of the thawing chamber 16 to the cooler 17. Also, 29,
30 and 31 are respectively the freezer compartments 13. Refrigerator room 14. This is a temperature detector that detects the temperature inside the thawing chamber 16.

Next, the detailed configuration of the defrosting chamber 15 will be explained. 32
33 is a heat insulating material installed on the inner surface of the outer box 32 and surrounding the outer periphery thereof. 34 is a far-infrared heater installed in the upper part of the thawing chamber 15. A ceramic paint layer 37 mainly composed of silicon or the like is baked on the surface of a glass tube 36 in which a heater wire 35 is enclosed to a thickness of about 6 μm or more. It is configured to effectively radiate 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. Further, the reflective plate 39
The inner box portions constituting both side walls and the back wall of the thawing chamber 16 are also integrally formed, and a large number of ventilation holes 4o are formed in the flat portions on both sides of the top dome portion. Next, 4
1 is a bottom plate made of metal such as aluminum, 42 is a linear heater fixed to the back surface of the bottom plate 41 with aluminum foil or the like for thermal conduction, and 43 is the back surface of the bottom plate 41. This is a temperature sensor placed close to the center for thermal conduction.

A thawing tray 44 is detachably installed on the bottom plate 41, and is composed of a tray 4e 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. .

48 is a protective net for preventing burns that is fixedly installed below the reflecting plate 39 at a certain interval; 49 is a thawing chamber 16;
This is a door that opens and closes the front opening of the

Further, 6o is a ventilation passage formed in the space on the back surface of the reflector plate 39, and the damper thermometer 2o is connected through the discharge port 61.
is connected to. 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 18 and the blower 18 are connected to a power source through a relay contact 64 and a relay contact 66, respectively. The far-infrared heater 34 and the heater 42 are connected to a power source via a relay contact 56 and a relay contact 67, respectively. Also, electromagnetic carp / L / 2 of damper thermo for thawing room.
1. The electromagnetic coils 21 of the damper thermos for the refrigerator compartment are connected to the power supply via relay contacts 58 and 69, respectively.

60 is a freezing room temperature control device, which includes a temperature sensor 29 such as a thermistor. A comparison circuit including resistors R1, R2, R3, a comparator 61, and a transistor 62. A relay coil 63 is provided, and the output of the comparator 61 is connected to the base of the transistor e2. Further, the collector of the transistor 62 is connected to the relay coil 63 for attraction, which opens and closes the relay contact 54 . 64
is a refrigerator room temperature control device, and a temperature sensor such as a thermistor 3
0, resistors R4, R6, R6, a comparator circuit including a comparator V35, a transistor 66, and a relay coil 67, and the output of the comparator 66 is connected to the base of the transistor 66. transistor 6
The relay coil 67 for suction, which opens and closes the relay contact 69, is connected to the collector 6. 68 is a thawing chamber temperature control device, which includes a temperature sensor 31 such as a thermistor.
A comparison circuit including a resistor R7°R8, R9 and a comparator 69, and an OR circuit 70. ) Ranjstav 1. Equipped with a relay coil 72, the temperature inside the defrosting chamber 15 is about -3°C during normal cooling! A resistor is constructed so that the temperature is regulated to the reefing temperature. The output of the comparator 69 is connected to one input of the OR circuit 7o.

Further, 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, which opens and closes the relay connection 68.

73 is a thawing control device, which includes a temperature sensor 43. Resistance R1°.

R111R12' Comparison circuit with comparator 74, timer 75, 76, 77, AND circuit 78°9. O
R circuits 80, 81, 82, the OR circuit 70, inverter 83. Transistors 84, 85.

86, relay coils 87, 88, 89, and the defrosting switch 63.

The output of the defrosting switch 63 is the output of the timer 7.
6 is connected to the input of the timer 75 (D output is the AND circuit 78, 79, one input of the OR circuit 70, 82, respectively, and the input cuff 6b, 7 of the timer 76.
7b. The output of the comparator 74 is connected via the inverter 83 to the other input of the AND circuit 78 and at the same time to the other input of the AND circuit 79. The AND circuit 78
The output of is connected to one side of the OR circuit 80.81,
The output of the AND circuit 79 is connected to the input cuffs 6a, 77a of the timer 76, 77. The output of the timer 76.77 is connected to the other input of each of the OR circuits 80.81.
The outputs of 1 are connected to the bases of the transistors 84 and 86, respectively. The relay coils Iv87 and 88 for attraction are connected to the collectors of the transistors 84 and 85 for opening and closing the relay contacts 56 and 57, respectively. 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 output of the OR circuit 82 is connected to the output of the transistor 86.
connected to the base of. and the transistor 8
A suction glue L/89 for opening and closing the relay contact 66 is connected to the collector 6.

Here, the timer 76 is set to "High" once for the input.
(hereinafter referred to simply as "H"), the "'H" signal continues to be output for a predetermined time t, and then becomes "'Low" (
The timers 76 and 77 are configured to switch to a signal of the input cuffs 6a and 7.
When an H" signal is input to 7a, the signals of 'H" and "L" are output alternately for a predetermined period of time for a time t1, but at time t1, the input cuffs 7b and 76b of the timer 76.77 change from L" to H".
Then, the time t until the inlet cuffs 6a and 76a change from L'' to 'H'' is counted and the value is 70 multiplied by a certain multiplier. Next, lower the output rate and output for time t2, and time t2 is also t.
is multiplied by a certain magnification. For example, specifically, the output rate of the timer 76 is 80 at the first time t.
%, t1=2t, and the next output rate is 40%, t2.1.5.

Further, the output of the timer 77 is assumed to have an output rate of 80% for the first time and an output time t 1' =2 t. Next, the configuration is such that t2'=1.6 at an output rate of 0%. The operating time of the timers 76 and 77 is t1+t2=t1'+t
2', and the predetermined time t of the timer 76 is the operating time of the timers 76 and 77, t1+t2=
It is set to be sufficiently longer than t1'+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 becomes small and the output force of the comparator 61 becomes "L", so the transistor 62 is turned on and the relay coil 63 is turned on. conducts. Therefore, relay contact 64 is closed and compressor 16 is operated.

At the same time, the output of the OR circuit 82 is also high, so the transistor 86 is turned on and the relay coil 89 becomes conductive. Therefore, the relay contact 56 is closed and the blower 18 is also operated and the freezer compartment 13 is turned on. .Cold air is forced into the refrigerator compartment 14° and the thawing compartment 15 for cooling.

Thereafter, when the freezer compartment 13 is cooled to a predetermined temperature, the output of the comparator 6, which has a large resistance value, of the temperature detector 29 becomes "L". Therefore, the transistor 62 is ○FF
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 1V63.B9 is cut off. Therefore, the relay contacts 54 and 55 are both open to the compressor 16 and the blower 18. After that, 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 30 becomes small and the comparator 6
5 becomes H", transistor 66 turns on and relay coil 67 becomes conductive. Therefore, relay contact 5
9 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. After that, the refrigerator compartment 14
When the temperature sensor 30 is cooled down to a predetermined temperature, the resistance value of the temperature sensor 30 increases and the output of the comparator 66 becomes L''.

Therefore, the transistor 66 is turned off and the relay coil A
The energization to /67 is cut off, the relay contact 69 is opened, and the energization 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, 6° C.).

In addition, when 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 small and the output of the comparator θ9 becomes H'', so the output of the OR circuit 70 becomes H''. Then, the transistor OFF 1 turns on and the relay coil 72 becomes conductive. For this reason, relay contact 68
is closed, the electromagnetic coil /l/21 is energized, the damper 24 of the damper thermostat 2° is opened, and cold air is introduced into the thawing chamber 16 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 becomes large and the output of the comparator 69 becomes L''. Therefore, the output of the OR circuit 70 becomes L'' and the transistor 71 is turned off, the current to the relay coil 72 is cut off, the relay contact 58 is opened, and the current to the electromagnetic coil 21 is also cut off.

Then, the damper 24 of the damper thermostat 2o is closed to prevent cold air from flowing into the thawing chamber 16.

Thereafter, by repeating this action, the interior of the thawing chamber 16 reaches the third temperature between the freezing temperature and the refrigeration temperature suitable for preserving fresh foods, as described above.
temperature range, i.e. approximately -3℃ Parsha! The temperature is maintained within the refereeing temperature range.

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 15, and then the thawing switch 6 is turned on.
Insert 3. At the same time as the input, the timer 76 starts outputting an "H" signal, and the AND circuit 78. At this time, one input of the thawing chamber 16 becomes H". At this time, the bottom plate 41 of the thawing chamber 16 conducts heat with the thawing tray 44 on which the frozen food 46 of low temperature (for example, -2CI) is placed. The temperature is decreasing.

That is, the temperature sensor 43 is in a sufficiently low temperature state. Therefore, the output of the comparator 4 becomes "L", and the signal inverted to "H" by the inverter 83 is output to the AND circuit 7.
8 is input to the other input. On the other hand, AND circuit 7
9, the "L" signal without passing through the inverter 83 is input as is. Therefore, the output of the AND circuit 78 is H”A
Since the output of the ND circuit 79 becomes “L”, the timer 76
．． 77 does not operate and the output of OR circuit 80.81 is “H”
As a result, transistors 84 and 85 are turned on. And relay carp) VS2. BB is energized and relay contact 56
．． 57 is closed and the far infrared heater 34. Heater 42
is continuously energized.

When the thawing action progresses and the temperature sensor 43 rises to a predetermined temperature (for example, 3 o'c) (the time required for this is t), the output of the comparator 74 becomes H'', and the inverter 83 The “L” signal is input to the AND circuit 78 through the
''.On the other hand, the input cuffs 5a and 77a of the AND circuit 79
Since the H' signal is input to the AND circuit 78.77
outputs p"H"I," signals alternately and repeatedly at a predetermined intermittent rate. Therefore, the transistor 84.85 outputs ○ via the OR circuit 80.81 at the corresponding intermittent output rate. Then, the relay coils 87, 88 are de-energized and the relay contacts 56, 67 are intermittently opened and closed.As a result, the far-infrared heater 34 is activated for a period of time following the continuous energization time t. At time t1, the energization rate is 80%, and at the next time t2, the energization rate is 40%, and the heat generation capacity is controlled to gradually decrease as time passes.Here, 11=2
to, t2=1. Timer 76°7 to become st○
7 sets the energization time. Further, the heater 42 is continuously energized for the time t. During the subsequent time t1', the energization rate is controlled to be 80%, and during the next time t2', the energization rate is decreased to Q%. Also, the energization time t'=2to.

The relationship is t2=1.5t0. Here, the energization time t1
1 t21 t1' l t2' was obtained experimentally, and the energization rate after continuous energization was determined, and the magnification was determined so that food of various weights could actually be thawed and the thawing state would be just right. be. In this way, in the early stages of thawing when the temperature of the food to be thawed is low, it takes a long time for the temperature of the temperature sensor 43 to rise to a predetermined temperature. Both heaters of the heater 42 are continuously energized, and then the energization rate is reduced in two stages, and the energization time is determined by multiplying to by a certain multiplier, so even if the weight of the food to be thawed 45 varies, the temperature can be detected. Depending on the degree of temperature rise in the container 43, thawing can proceed for just the right amount of time for each weight, and the thawing time can also be shortened. Since the heat generating capacity gradually decreases over time, thawing proceeds while suppressing a rise in the surface temperature of the food 45 to be thawed. During thawing, the food to be thawed 45
On the other hand, from the top surface, radiant heating from the far-infrared heater 34 is performed evenly in combination with the reflection action of the reflecting plate 39, and from the bottom surface, conductive heating by the heating heater 42 is performed simultaneously. Here, when heating 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 46. The far infrared rays are absorbed and penetrate relatively far into the interior of the food to be thawed 46, so that 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, these far infrared heaters 34. Simultaneously with the heating action by the heater 42, during defrosting, that is, while the output of the timer 76 continues to generate an "H" signal, the output of the OR circuit 70.
Turns ON and ') V-Coy/I/72°89 becomes conductive. Therefore, the relay contacts 58 and 55 are closed and the electromagnetic coil 21 is closed regardless of the output of the defrosting chamber temperature control device 68.
is energized, the damper 24 of the damper thermometer 2o for the thawing chamber is forcibly opened, and the blower 18 is forcibly operated regardless of the output of the freezing chamber temperature control device 6Q.

The cool air forced through the damper 24 by the blower 18 is passed through the discharge duct 26 to the discharge port 6.
1 and flows into the ventilation passage 60 in the upper part of the thawing chamber 15. The cold air that has flowed into the ventilation path 5o is discharged downward from a large number of ventilation holes formed in the reflection plate 39, and uniformly cools the surface of the food to be thawed 45.

Due to this action, the food to be thawed 46 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 control effect of gradually reducing the heat generation capacity of the heater 42, the temperature rise at the surface is further suppressed, resulting in less uneven thawing with a small temperature difference between the center and the surface. Thawing can be realized (the temperature characteristics and time chart of the food 46 to be thawed during thawing are shown in FIG. 6).

In addition, the thawing time is relatively short due to the internal penetration effect of far infrared rays and continuous heating control in the initial stage of thawing (for example, thawing is about 3 ohm for a tuna weighing 500 g and 251 fi thick).
In addition, since the reflector plate 39 is exposed in the ventilation path 6Q, the temperature of the reflector plate 39 itself and surrounding members, which would normally reach a considerably high temperature, is cooled and lowered, which is advantageous in terms of safety.

The cold air that has flowed into the thawing chamber 16 is collected into the cooler 17 through the suction duct 28 from the suction port 62 opened at the rear surface after the cooling effect.

As this thawing action progresses, time t0+t1+t2=
When t0+t1'+t2' elapses, timer 76.77
At the same time, the output of the transistor 84.
5 are turned off, the power to relay coils/L'87 and 88 is cut off, relay contacts 66 and 57 are opened, and far infrared heaters 34 and 34 are turned off. The power supply to the heater 42 is cut off and thawing is completed. At the same time, one input of the OR circuit 70.82 becomes "L", so the forced operation state of the blower 18 and the forced open state of the damper 24 of the damper thermos 20 for the thawing chamber are canceled.

After thawing, the temperature sensor 3
The temperature inside the defrosting chamber 16 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 about -3°C, and the temperature does not rise further 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 45 to be thawed can be used at any time after thawing is completed, 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 conductive heating using a heating heater from the bottom. Moreover, during thawing, the heat generation capacity of both heaters is 2
Combined with the gradual decrease in temperature and the effect of far infrared rays penetrating into the food to be thawed, thawing with less temperature unevenness between the center and surface becomes possible.

(2) 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, and then the energization rate is reduced in two steps, but the energization time is determined by the temperature sensor. The time it takes for the food to reach the specified temperature is determined by multiplying it by a predetermined fixed factor, so even if the weight of the food to be thawed changes, the maximum capacity heater can rapidly heat it for the appropriate time, ensuring proper thawing. You can finish defrosting in the current state.

(3) During thawing, the damper thermo for the thawing chamber is forcibly opened, and the blower is forced to operate continuously, allowing cold air to descend and flow into the food to be thawed through the ventilation path formed in the space on the back of the reflector. As a result, 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 thawing, the reflector and other surrounding parts, which would normally become hot, are exposed to the ventilation path and cooled, which lowers the temperature, which is also convenient for safety.

(6) After thawing is completed, the interior of the thawing chamber is kept cool at the third temperature range between the freezing and refrigerator temperatures (for example, the par 7 Yalf freezing temperature range of approximately -3°C), so the residual heat immediately after thawing is The temperature of the food to be thawed 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 longitudinal sectional view of the refrigerator with a thawing chamber shown in Figure 1, Figure 4 is an enlarged cross-sectional view of the damper thermometer installed at the entrance of the thawing chamber shown in Figure 1, and Figure 5. is an electric circuit and control circuit diagram of the refrigerator with a thawing chamber shown in Fig. 3, Fig. 6 is a time chart during thawing and a temperature characteristic diagram of the food to be thawed, and Fig. 7 is a perspective view of a thawing box showing a conventional example. FIG. 8 is a sectional view taken along the line EB' of the thawing box shown in FIG. 7. 13... Freezer room, 14... Refrigerator room, 1
6... Thawing chamber, 16... Compressor, 17
...Cooler, 18...Blower, 2o.
... Damper thermo, 34 ... Far infrared heater, 39 ... Reflector, 4o ... Ventilation hole, 41 ... Bottom plate, 42 ... Heater, 43 ... Temperature detector, 44 ...
- Thawing dish, 45...Food to be thawed, 49...
...door, 60...--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 provided with a door that can be opened and closed, a compressor and a cooler for the refrigeration cycle, and air cooled by the cooler. A blower that provides forced ventilation in the freezer, refrigerator, and thawing rooms;
a far-infrared heater provided at the top of the thawing chamber; a metal bottom plate provided at the bottom of the thawing chamber; a heater thermally conductively adhered to the back surface of the bottom plate; and a back surface of the bottom plate. A temperature sensor is placed in thermally conductive contact approximately at the center of the heater, a metal reflector plate covers the top surface of the far-infrared heater in a dome shape, and the food to be thawed is placed on the bottom plate in a thermally conductive manner. , and a thawing tray that is detachably installed, a damper thermo that is provided at the inlet of the cold air of the thawing chamber and that adjusts the amount of cold air inflow by an electrical input, and a space above the back surface of the reflector that communicates with the damper thermo. a ventilation passage formed in the reflector, and a large number of ventilation holes that communicate the ventilation passage with the inside of the thawing chamber, and
During thawing, the damper thermo is forcibly opened and the blower is forced to operate, and the far-infrared heater and the heating heater are continuously energized for the time from the start of thawing until the temperature of the temperature sensor rises to a predetermined temperature. , when the temperature of the temperature sensor rises to a predetermined temperature, a first
Reduce the energization rate to the two heaters for a time multiplied by a certain multiplier, and then reduce the energization rate to the two heaters for a time multiplied by a second fixed multiplier by the time required for the temperature of the temperature sensor to rise to a predetermined temperature. Thereafter, the energization rate to both heaters is reduced in two stages, and each energization time is set by a fixed multiplier to the time until the temperature of the temperature sensor rises to a predetermined temperature. The refrigerator is equipped with a thawing chamber, and the thawing control device maintains the temperature in a third temperature range between the thawing chamber and the refrigerating temperature and the freezing temperature when not thawing.