JPH063022A - Refrigerator with defreezing chamber - Google Patents

Abstract

PURPOSE:To provide excellent defreezing finish even when a food is changed and to hold freshness in environment suitable for preservation of a food, such as fish meat, even when the food is left standing as it is after defreezing, in a refrigerator with a defreezing chamber to defreeze a frozen food. CONSTITUTION:A refrigerator with a defreezing chamber comprises a radiation heater 29, a temperature sensor 30 thermally conductively adhered to a bottom plate 26, a blower 17 by which cold air is introduced during defreezing, and a damper device 18 to regulate an amount of cold air. Further, a control means is provided for controlling introduction of cold air with the aid of the blower 17 and the damper device 18 and controlling the energizing time and the factor of the radiation heater 29 by means of the temperature of a temperature sensor 30 at a first stage and a time in which the temperature of the temperature sensor 30 is increased to a value higher than temperature at a first stage by a given temperature.

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 food is known. For example, Japanese Patent Publication Sho 48
This is the example shown in Japanese Patent Publication No. 25414, and FIG.
It will be described with reference to FIG. Reference numeral 1 denotes a thawing box, which includes an outer box 2 made of metal or synthetic resin, and an inner box 3 made of aluminum or the like having a large thermal conductivity and provided inside the outer box 2 with an appropriate interval. Has been formed. Reference numeral 4 denotes a linear heater, which is heat conductively adhered to the inner box 3 by an aluminum foil 5 such that the bottom surface of the thawing box 1 is sparse and the top surface is dense. 6 is the outer box 2 and aluminum foil 5
It is a heat insulating material interposed between.

In such a structure, when the food to be thawed 7 is placed on the bottom of the thaw box and the thaw action is started, the heater 4 is heated.
The heat is applied from the entire circumference of the inner box 3 to heat the food 7 to be thawed to cause the food to be thawed.

[0004]

However, in such a configuration, although heat can be transferred from the bottom portion of the thawing box 1 to the bottom portion of the food 7 to be thawed by heat conduction, the bottom portion can be thawed. There is almost no radiant heating from the top and side surfaces of the box 1, and heating is performed mainly by convection of warm air in the thawing box 1.

Therefore, there is a problem that the thawing unevenness with the central portion of the food to be defrosted 7 is likely to be large, the thawing time is long, and the thawing quality depends on the food. If the food is left as it is after the completion, the quality of the fish, such as fish meat, will change due to the high ambient temperature.

Therefore, after the thawing is completed, the user needs to be careful and perform the processing, and there is also a problem that the user cannot use it at ease. There is also a problem that the finished state is not constant depending on the food.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a thawing chamber, which has less thawing unevenness and can be thawed in a short time and with peace of mind, particularly in a refrigerator.

[0008]

In order to solve the above-mentioned problems, a refrigerator according to the present invention has a radiation heater covered with a curved reflecting plate.
In the defrosting chamber, which has a temperature sensor that is attached to the upper surface of the bottom plate and a back surface of the bottom plate in a heat conductive manner on the lower surface, cool air whose flow rate is adjusted by a blower and a damper device is introduced. As the first step, the radiating heater is energized at the first duty ratio for a certain period of time, and as the second step, the time until the temperature sensor raises the temperature predetermined according to the temperature of the temperature sensor in the first step. The radiating heater is energized at a second duty ratio smaller than the first duty ratio, and the subsequent steps are conducted according to the temperature of the first stage temperature sensor and the time required for the second stage. While heating the food to be thawed by energizing at a third energization rate smaller than the rate, the blower is forced to operate, the damper device is forcibly opened, the thaw chamber between the refrigeration and freezing temperatures except when thawing. It is equipped with a control means to keep it in the three temperature zones. That.

[0009]

According to the present invention, as described above, the radiating heater is energized at the first duty ratio for a certain period of time during the thawing and the temperature sensor is the first stage temperature sensor during the second stage. The temperature of the temperature sensor of the first stage and the temperature of the temperature sensor of the first stage The thawed food is heated by energizing it at a third energization rate smaller than the second energization rate according to the time required for the second step.

Indirect radiation occurs through the upper surface and the reflecting surface of the food to be thawed, and the food to be thawed absorbs heat almost uniformly. Then, the blower is forcibly operated, the damper device is opened, and cold air is introduced. Therefore, the rise in the surface temperature of the food to be thawed is suppressed. The thawing chamber is maintained in the third temperature zone between the refrigerating and freezing temperatures except during thawing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator with a thawing chamber showing an embodiment of the present invention will be described below with reference to FIGS. Reference numeral 8 denotes a refrigerator body, which 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 cooling room (hereinafter referred to as refrigerating room 12), and 13 is a refrigerating room 1.
It is a freezer compartment formed in the upper part of 2. Reference numeral 15 is a compressor of the refrigeration cycle provided at the bottom of the refrigerator main body 8, and 16 is a cooler provided on the back surface in the freezing compartment 13.

Reference numeral 17 denotes a blower for forcibly passing the cool air cooled by the cooler 16 into the refrigerating compartment 12, the freezing compartment 13 and the thawing compartment 14, and 18 is provided at the inlet of the thawing compartment 14 to inflow cold air by electric input. A damper device for adjusting the amount (hereinafter referred to as damper thermo 18), which is configured to open and close the damper 20 by the driving force of the motor 19. Reference numeral 21 denotes a discharge duct for guiding the cool air from the blower 17 to the thawing chamber 14, 2
Reference numeral 2 is a suction duct for returning cold air that has cooled the inside of the thawing chamber 14 to the cooler 16. Next, the detailed configuration of the thawing chamber 14 will be described.

Reference numeral 23 is an outer box made of synthetic resin, and 24 is an inner box made of metal such as aluminum, and has a curved reflection plate 25, a bottom plate 26 and both plates 25 which are arranged below the reflection plate 25 so as to face each other. , 26 is formed by a side plate 27 having a substantially U shape connected to three sides. Reference numeral 28 denotes a door that is openably and closably provided at the front opening of the inner box 24, and has a double structure made of synthetic resin that forms an air layer to improve heat insulation.

Reference numeral 29 is a radiant heater made of a quartz glass tube, which is provided facing the reflection plate 25 of the inner box 24 at a predetermined interval, and radiates far infrared rays of about 5 μm or more by itself. A ceramic paint containing silicon as a main component may be baked and applied to further improve the radiation efficiency of far infrared rays. Reference numeral 30 denotes a temperature sensor such as a thermistor that is heat conductively attached to the vicinity of the center of the back surface of the bottom plate 26.

Reference numeral 33 denotes a thawing dish which is detachably installed on the bottom plate 26 and on which the food to be thawed 34 is placed. Reference numeral 35 is a protective net for preventing burns which is attached so as to cover the radiant heater 29 at a constant interval. Reference numeral 37 is a heat insulating material inserted between the outer box 23 and the inner box 24, and a discharge air passage 38 communicating with the discharge duct 21 and the damper thermo 18 is formed in the upper portion, and a suction air passage 39 communicating with the suction duct 22 is formed in the rear portion. is doing.
Reference numeral 40 denotes a discharge port formed in the reflection plate 25 of the inner box 24 so as to connect the inside of the thawing chamber 14 and the discharge air passage 38, and 41 denotes of the inner box 24 so as to connect the inside of the thawing chamber 14 and the suction air passage 39. It is a suction port formed in the side plate 27.

Reference numeral 42 is an operation plate provided on a part of the outer shell of the refrigerator main body 8 for selecting a finish state (eg, "hard", "standard", "soft") desired by the user. A finish setting key 44 (in this case, "standard" if nothing is set) and a defrosting switch 45 for starting or stopping the defrosting operation are provided.

Next, the control relationship will be described. Reference numeral 46 denotes a control means (hereinafter referred to as a microcomputer 46) including a microcomputer and the like, and a first stage of defrosting control including three stages (hereinafter referred to as a stage).
Timer 47 for counting the time of the second stage, timer 48 for counting the time of the second stage, timer 49 for counting the time of the third stage, and, for example, intermittent energization rate X% (O
N ... x1s, OFF ... x2s)
A timer 51 for setting the intermittent energization rate Y% (ON ... y1s, OFF ... y2s) is built in.

Then, the input terminal of the microcomputer 46 has a freezing room temperature detecting means 5 for detecting the temperature in the freezing room 13 for controlling the operation of the compressor 15 and the blower 17.
2. Food temperature detecting means 53 having the temperature sensor 30, defrosting room temperature detecting means 54 composed of the same temperature sensor 30,
The decompression switch 45 is connected, and the compressor 1 is connected to the output terminal.
5, drive means 55, 56 such as an electromagnetic relay for driving the blower 17, the damper thermostat 18, the radiant heater 29,
57 and 58 are connected.

The operation of the above arrangement will be described with reference to the flow charts and time charts shown in FIGS.

First, the food to be thawed (for example, beef steak meat having a thickness of 20 mm) 34 to be thawed is placed on the thaw plate 33 substantially at the center and set on the bottom plate 26. First, in STEP 1, the thawing operation is started by turning on the thawing switch 45. When the defrosting control starts, the timer 47 of the first stage starts time counting in STEP2, and subsequently in STEP3, the radiant heater 29 (for example, 100 W) is continuously energized, the blower 17 is forcibly operated, and the damper 20 of the damper thermostat 18 is activated. Is forcibly released. Therefore, far infrared rays having a size of 5 μm or more are continuously and directly radiated from the top surface directly or indirectly through the reflection plate 25 to the food to be defrosted 34.
In general foods having an absorption wavelength band in the far-infrared wavelength range, far-infrared rays are efficiently absorbed, and heat quickly penetrates into the inside of the food to be defrosted 34.

By such continuous heating, the temperature of the food to be thawed 34 which is in a frozen state (for example, -20 ° C) in the first stage can be quickly raised.

On the other hand, the cool air cooled by the cooler 16 is guided to the discharge air passage 38 in the thawing chamber 14 via the discharge duct 21 in the refrigerator body and the damper thermostat 18 by the forced air blowing action of the blower 17. Blow-down air is blown from a large number of the outlets 40. Therefore, the radiant heater 2 described above
Combined with the effect of heat permeation into the food by far-infrared radiation of 9, the food to be defrosted 34 while suppressing the temperature rise on the surface
Thawing proceeds in a state where the temperature unevenness between the surface and the center of the rice does not increase. In addition, the air warmed by the heating action in the thawing chamber 14 is returned to the cooler 16 from the suction port 41 and the suction air passage 40 provided at the rear of the room through the suction duct 22 of the refrigerator main body 8 and cooled again. Repeat the circulation.

While the continuous heating action including such cooling action proceeds, in STEP 4, the timer 4 of the first stage is started.
It is determined whether or not the count time of 7 has reached a certain time t1 (for example, 15 minutes), and if not reached, the process waits until it reaches at STEP4.

In STEP 4, the timer 47 sets t1 (15 minutes).
When the first stage is counted, the temperature T1 (for example, 10 ° C.) of the temperature sensor 30 at this time is stored in the microcomputer 46 as the temperature of the first stage.
Here, the first stage temperature T1 correlates with the ease of thawing food.

Following this, the flow proceeds to STEP 5,
The second stage time timer 48 starts counting time. Then, at the same time when the timer 48 counts, the STE
Proceeding to P6, the radiation heater 29 is energized intermittently at the intermittent energization rate X% = [x1s / (x1 + x2) s] × 100 (for example, 80% ... x1 = 60s, x2 = 15s) of the timer 50. The blower 17 is forcibly operated, the damper 20 of the damper thermo 18 is forcibly opened, and cold air is continuously introduced.

In this way, in the second stage, since the heating amount is kept smaller than that in the first stage and the heating is intermittent, the transfer of heat from the surface of the food to be defrosted 34 to the center is promoted. Together with this, thawing proceeds while suppressing the rise in surface temperature due to cold air.

While the intermittent heating action including the cooling action proceeds, the temperature T of the temperature sensor 30 is determined in STEP7.
Has a predetermined temperature A increased from the first stage temperature T1 (T
≧ T1 + A; for example, A = 5), and if not rising, wait in STEP7. This predetermined temperature A is (Table 1)
As shown in, the first stage temperature T1 is predetermined and set.

[0028]

[Table 1]

When it is determined in STEP 7 that the temperature has risen, the second stage is ended, and the process proceeds to STEP 8 to proceed to the second stage.
The timer 48 of the stage stops counting the time, and the required time t2 (for example, 8 minutes) of the second stage is stored in the microcomputer 46 as the second stage time. Second here
The stage time t2 has a correlation with the progress of thawing of food.

Then, in STEP 9, the timer 49 of the third stage starts time counting. The set time of the timer 49, that is, the time t3 of the third stage is predetermined and set by the temperature T1 of the first stage and the time t2 of the second stage as shown in (Table 1) ( For example 5
Minutes).

Then, at the same time when the timer 49 counts the time, the process proceeds to STEP 10, and the radiation heater 29 causes the intermittent current rate Y% of the timer 51 = [y1s / (y1 + y2) s] × 10.
0 (for example, 40% ... y1 = 20s, y2 = 30s) is energized intermittently. The blower 17 and the damper 20 of the damper thermostat 18 are forcibly operated or forcibly opened, and cold air is continuously introduced.

In this way, in the third stage, the heating amount is further suppressed as compared with the second stage, and the heating action is carried out by mixing cold air, so that the temperature rise of the surface of the food to be defrosted 34 is sufficiently suppressed. As a result, the temperature difference between the central portion and the surface portion is small, and thawing without uneven thawing can be realized.

While thawing proceeds in this way, STEP
At 11, it is determined whether or not the count time of the timer 49 has reached t3 (5 minutes), and if not reached, at STEP 11, the process waits until it reaches. In STEP 11, the timer 49 is t
When 3 (5 minutes) is counted, the third stage ends, and S
At TEP 12, the power supply to the radiant heater 29 is stopped, the forced operation of the blower 17 and the forced opening of the damper thermostat 18 are released, and the thawing is automatically completed.

The finish setting switch 44 is "hard"
If "and softening" is selected, it is possible to finish harder and softer than "standard" by increasing or decreasing the heating amount of the second stage and the third stage.

If the food 34 to be defrosted changes, the cold heat capacity and the defrosting efficiency of the food also change, so the temperature rise gradient of the temperature sensor 30 changes and the temperature T1 of the first stage and the time t2 of the second stage change. . Since the heating is controlled according to the value, appropriate thawing is performed according to the change in food.

Regarding the thawing time, a relatively short time (for example, a weight of 200) is obtained due to the internal penetration effect of far infrared radiation.
Beef steak with a thickness of 20 mm and a thickness of about 25 minutes can be thawed.

After thawing, the temperature inside the thawing chamber 14 is controlled based on the temperature detected by the temperature sensor 30 as in the case of normal cooling. Therefore, the thawed food 34 after thawing is immediately cooled so as to stabilize at the partial freezing temperature of about -3 ° C, and the temperature does not rise further due to residual heat.

Even after the thawing is finished, it is kept at a partial freezing temperature suitable for preserving organisms such as fish and meat, so that the user can monitor the end of the thawing immediately as in the conventional case. There is no need to process it, and you can safely decompress it. Further, the food to be defrosted 34 can be used at any time after the end, which is extremely convenient.

[0039]

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

(1) Efficient heating mainly by far-infrared rays is performed by the radiant heater, and the heat generation amount of the radiant heater is gradually reduced during thawing, and the effect of penetrating far-infrared rays into food is also combined. As a result, thawing with less temperature unevenness between the center and the surface can be achieved.

(2) During the thawing, cold air is made to flow down into the food from the upper part of the room, so that the surface of the food is cooled uniformly, the temperature rise is further suppressed, and the deterioration of the food is prevented.

(3) Since the radiant heater is energized to perform rapid heating in the initial stage of thawing, thawing can be performed in a short time while maintaining quality.

(4) The easiness of thawing and the progress of thawing of food can be indirectly detected by the temperature rising gradient of the temperature sensor, and the thawing is performed by setting an appropriate heating time and a heater energization rate based on these values. Therefore, good thawing finish can be obtained in various foods.

(5) By automatically judging the ease of thawing and the progress of thawing of the food, there is no need for the user to check them and it is extremely convenient.

(6) After the thawing is finished, the thawing chamber is kept in the temperature zone between the freezing room temperature and the refrigerating room temperature (for example, the partial freezing temperature of about -3 ° C.), so that the residual heat immediately after the thawing finishes the food. The temperature does not rise, the freshness is maintained in an environment suitable for preserving living things such as fish meat even if it is left as it is, and the food can be used at any time, which is extremely convenient.

[Brief description of drawings]

FIG. 1 is a perspective view of a thawing chamber showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line A-A ′ of the thawing chamber of FIG.

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

FIG. 4 is an enlarged view of a thawing operation plate of the refrigerator with a thawing chamber of this embodiment.

FIG. 5 is a control block diagram of a refrigerator with a thawing chamber according to the present embodiment.

FIG. 6 is a flow chart of thawing control of the refrigerator with a thawing chamber of this embodiment.

FIG. 7 is a temperature characteristic of the time chart during thawing and the food to be thawed in the refrigerator with a thawing chamber of the present embodiment.

FIG. 8 is a perspective view of a conventional thawing box.

9 is a cross-sectional view of the defrosting box of FIG. 8 taken along the line B-B ′.

[Explanation of symbols]

 12 Cooling Room 14 Thawing Room 16 Cooling Room 17 Blower 18 Damper Device 25 Reflector 26 Bottom Plate 29 Radiating Heater 30 Temperature Sensor 44 Finish Setting Key 45 Thawing Switch 46 Control Means

Claims (1)

[Claims] 1. A reflecting plate having a curved reflecting surface, a radiant heater provided below the reflecting plate at a predetermined interval, a bottom plate arranged to face the reflecting plate, and the bottom. A thaw chamber equipped with a temperature sensor that is heat conductively attached to the back surface of the face plate, a cooling chamber equipped with the thaw chamber in one section, and cold air cooled by a cooler of a refrigeration cycle is forced into the thaw chamber. A blower for ventilation, a damper device provided at the inlet of the thawing chamber to adjust the amount of cold air flowing in, a thawing switch for starting the thawing action, and a radiating heater for a certain period of time as a first step during thawing. The current is applied at a duty ratio, and as a second step, the time until the temperature sensor rises a predetermined temperature according to the temperature of the temperature sensor in the first step Energize at the duty ratio, and the subsequent steps are the temperature sensor of the first step Depending on the temperature and the time required for the second step, the food to be thawed is heated by energizing it at a third energization rate smaller than the second energization rate, and the blower is forcibly operated, and the damper device is forcibly opened. And a refrigerator with a thawing chamber provided with control means for maintaining the thawing chamber in a third temperature zone between refrigerating and freezing temperatures except when thawing.