JP7369932B2 - refrigerator - Google Patents

Description

The present invention relates to a refrigerator that can defrost food.

For example, Patent Document 1 discloses a freezer capable of thawing frozen foods. The freezer of Patent Document 1 has a high-frequency heating chamber in which food to be thawed is stored and the stored food is subjected to high-frequency heating (dielectric heating). The high-frequency heating chamber is configured to allow introduction of cold air from the freezing chamber. Thereby, when not used for thawing, the high frequency heating chamber is used as a freezing chamber.

Japanese Patent Application Publication No. 2002-147919

By the way, in the freezer described in Patent Document 1, when thawed food is stored as it is in the high-frequency heating chamber, the user operates a temperature control switch to set the high-frequency heating chamber to a temperature suitable for storage, for example, refrigeration temperature. There is a need to. Therefore, if the user forgets to defrost the food, the temperature control switch may not be operated and the defrosted food may be left in the high-frequency heating chamber, which is not at an appropriate temperature.

Therefore, an object of the present invention is to appropriately preserve heated food that has been heated in the cooling/heating chamber and left as it is in a refrigerator equipped with a cooling/heating chamber capable of cooling and heating food.

According to one aspect of the present invention,
A refrigerator equipped with a cooling/heating chamber capable of cooling and heating food, the refrigerator comprising:
a heating section that heats the food by heating the inside of the cooling/heating chamber;
a heated food detection unit that detects whether heated food is present in the cooling/heating chamber after heating the food;
A refrigerator is provided that changes the cooling temperature of the cooling operation of the cooling/heating chamber based on the detection result of the heated food detection section.

According to the present invention, in a refrigerator equipped with a cooling/heating chamber capable of cooling and heating food, it is possible to appropriately preserve heated food that has been heated in the cooling/heating chamber and left as is.

A vertical sectional view of a refrigerator according to an embodiment of the present invention Block diagram showing the control system of a refrigerator Enlarged sectional view of freezing/thawing chamber Enlarged cross-sectional view of the freezing/thawing chamber showing the flow of cold air Cross section of heating module Cross-sectional view of a portion of the refrigerator body before incorporating the expansion module Exploded cross-sectional view of heating module Cross-sectional view of the heating module along line AA in Figure 5 Block diagram showing the control system of the heating section of the heating module Diagram showing changes in reflectance during food thawing Normal operation timing chart Timing chart diagram of rapid cooling operation Timing chart diagram of zone thawing operation Timing chart diagram of all-zone defrosting operation Flowchart diagram of zone thawing operation (all zone thawing operation)

A refrigerator according to one aspect of the present invention is a refrigerator that includes a cooling/heating chamber capable of cooling and heating food, and includes a heating section that heats the food by heating the inside of the cooling/heating chamber, and a heating section that heats the food by heating the inside of the cooling/heating chamber. and a heated food detection unit that detects whether heated food is present in the cooling/heating chamber after the heating is completed, and the heated food detection unit detects whether the heated food is present in the cooling/heating chamber based on the detection result of the heated food detection unit. Change the cooling temperature of the cooling operation.

According to this aspect, in a refrigerator equipped with a cooling/heating chamber capable of cooling and heating food, it is possible to appropriately preserve heated food that has been heated in the cooling/heating chamber and left as is.

For example, when the heated food is not detected by the heated food detection section, a normal operation may be performed in which the cooling temperature of the cooling operation of the cooling/heating chamber is maintained at the first cooling storage temperature.

For example, when the heated food is detected by the heated food detection section, the cooling temperature of the cooling operation of the cooling/heating chamber is set to a second cooling storage temperature higher than the first cooling storage temperature. A second cooling preservation operation may be performed to maintain the temperature.

For example, when a predetermined period of time has elapsed from the end of heating, the second cooling storage operation may be switched to the normal operation. This prevents the heated food from being stored at the second cooling storage temperature for a long period of time.

For example, the cooling/heating chamber may include a heating zone, which is a space in which food to be heated is placed, and a non-heating zone, which is a space continuous with the heating zone, in which food not to be heated is placed. When divided, the heating section applies an alternating voltage between an oscillation electrode and a counter electrode that are arranged to face each other across the heating zone of the cooling/heating chamber, and the oscillation electrode and the counter electrode. and an oscillating section that heats the food between them. In this case, when the heated food is detected by the heated food detection section, the heating section may heat the heated food while maintaining the cooling/heating chamber at the first cooling storage temperature. , maintaining the heated food product at the second chilled storage temperature. Thereby, the heated food can be brought to the second cooling storage temperature while the food in the non-heating zone is stored at the first cooling storage temperature.

For example, the heated food detection unit includes a reflected wave detection unit that detects a reflected wave returning to the oscillation unit, and a reflectance calculation unit that calculates a reflectance that is a ratio of the reflected wave to the incident wave output from the oscillation unit. The heated food detection section includes a first food detection section, wherein the reflectance is smaller than a value when the heated food is not present between the oscillation electrode and the counter electrode. The heated food may be detected when the value is smaller than a threshold value. Thereby, heated food can be detected.

For example, the refrigerator includes a door that opens and closes the cooling/heating chamber, and a door sensor that detects the opening and closing of the door, and the heated food detection section detects that the door opening/closing sensor detects that the door is opened after thawing is completed. If not, the heated food may be detected. Thereby, heated food can be detected.

For example, in the refrigerator, while the heating unit is heating the food, the reflectance increases and reaches a second threshold value that is smaller than the first threshold value. a matching part that performs impedance matching between the oscillation electrode and the counter electrode, and the impedance matching causes the reflectance to exceed a third threshold value that is smaller than the second threshold value. If the impedance matching does not decrease, the impedance matching execution timing may be set as the end timing of heating the food. Thereby, the second cooling preservation operation can be started after heating the food.

For example, the refrigerator has an operation section for receiving a heating start instruction from a user and for the user to input a heating time, and the timing when the heating time has elapsed from the timing when the start instruction was received is determined when the food is heated. It may also be the end timing. Thereby, the second cooling preservation operation can be started after heating the food.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of a refrigerator according to this embodiment. In FIG. 1, the left side is the front side of the refrigerator, and the right side is the back side of the refrigerator. Moreover, FIG. 2 is a block diagram showing the control system of the refrigerator.

As shown in FIG. 1, the refrigerator 10 includes a main body 12. The main body 12 includes an outer casing 14 made of a metal material and constituting the outer surface of the refrigerator 10, an inner casing 16 made of a resin material such as ABS and constituting the inner surface of the refrigerator 10, and an outer casing. The space between the body 14 and the inner housing 16 is filled with a heat insulating material 18 such as hard urethane foam.

The main body 12 of the refrigerator 10 includes a plurality of storage chambers for storing foods (ingredients, processed foods, etc.). In the case of this embodiment, the storage chambers include, from the top, a refrigerator compartment 12a, a freezing/thawing compartment 12b, a freezing compartment 12c, and a vegetable compartment 12d. Although not shown in the drawings, an ice-making chamber for making ice is provided on the right side of the freezing/thawing chamber 12b (on the back side of the drawing). Furthermore, the refrigerator 10 can also accommodate items other than food.

The refrigerator compartment 12a is a space where food is maintained in a temperature range where food does not freeze, for example, in a temperature range of 1° C. to 5° C. The freezing chamber 12c is a space maintained in a temperature range in which food is frozen, for example, in a temperature range of -22°C to -15°C. The vegetable compartment 12d is a space maintained at a temperature equal to or higher than that of the refrigerator compartment 12a, for example, 2°C to 7°C. The freezing/thawing chamber 12b will be described later.

In the case of this embodiment, a machine room 12e is provided in the upper part of the main body 12 of the refrigerator 10. The machine room 8 houses a compressor 20 that constitutes a refrigeration cycle of the refrigerator 10 and circulates refrigerant in the refrigeration cycle. In addition, instead of this, the machine room 12e can also be provided in the lower part of the main body 12 of the refrigerator 10.

In the case of this embodiment, a cooling chamber 12f is provided on the back side of the freezer compartment 12c and the vegetable compartment 12d. A cooler 22, which constitutes the refrigeration cycle of the refrigerator 10 and through which a refrigerant passes, is disposed within the cooling chamber 12f. Further, a cooling fan 24 blows the air (cold air) of the cooling compartment 12f cooled by the cooler 22 toward the refrigerator compartment 12a, the freezing/defrosting compartment 12b, the freezing compartment 12c, and the vegetable compartment 12d. It is provided. Furthermore, as shown in FIG. 2, dampers 26A to 26D that control the flow rate of cold air flowing into each chamber 12a to 12d are arranged in the flow path between each chamber 12a to 12d and the cooling fan 24 (see FIG. 1, only the damper 26B is shown).

Furthermore, as shown in FIG. 2, temperature sensors 28A to 28D are provided in each of the refrigerator compartment 12a, the freezing/thawing compartment 12b, the freezing compartment 12c, and the vegetable compartment 12d to measure the internal temperature thereof.

As shown in FIG. 2, the control unit 30 of the refrigerator 10 executes cooling control based on the measurement results of the plurality of temperature sensors 28A to 28D, that is, output control of the compressor 20 and rotation speed control of the cooling fan 24. , and the dampers 26A to 26D, the temperatures in the refrigerator compartment 12a, freezing/thawing compartment 12b, freezing compartment 12c, and vegetable compartment 12d are maintained appropriately. The control unit 30 is a board that includes a processor such as a CPU, a storage device such as a memory that stores programs, and a circuit, and the processor controls the compressor 20 and the cooling fan according to the program stored in the storage device. 24, and dampers 26A to 26D.

As shown in FIG. 2, in the case of this embodiment, the refrigerator 10 includes an operating section 32 for the user to operate the refrigerator 10, particularly the freezing/thawing chamber 12b. Note that the operation unit 32 may be a touch panel built into the refrigerator 10, and/or may be a user's mobile terminal. When the operation unit 32 is a mobile terminal, software (application) for operating the refrigerator 10 is installed on the mobile terminal. From here on, details of this freezing/thawing chamber 12b will be explained.

FIG. 3 is an enlarged sectional view of the freezing/thawing chamber 12b. Moreover, FIG. 4 is an enlarged sectional view of the freezing/thawing chamber 12b showing the flow of cold air. Note that the flow of cold air is indicated by a dashed line.

As shown in FIG. 3, in this embodiment, the freezing/thawing chamber 12b is configured by a heating module 40 built into the main body 12 of the refrigerator 10.

FIG. 5 is a sectional view of the heating module, and FIG. 6 is a sectional view of a portion of the refrigerator main body before the heating module is installed. FIG. 7 is an exploded cross-sectional view of the heating module. FIG. 8 is a cross-sectional view of the heating module taken along line AA in FIG.

As shown in FIGS. 5 and 8, the heating module 40 has a rectangular parallelepiped shape and is a double-walled structure including an inner case 42 and a shield case 44 that accommodates the inner case 42. Shield case 44 functions as a housing for heating module 40 . The inner case 42 defines a storage chamber in which food is stored, that is, a freezing/thawing chamber 12b.

Inner case 42 is made of an insulating material such as resin, and has a box shape with an opening on the front side. The shield case 44 is made of a material containing metal, for example, made of a metal material such as aluminum. Further, the shield case 44 has a box shape with an opening on the front side and stores the inner case 42 therein.

In the case of this embodiment, as shown in FIG. 7, the heating module 40 includes a drawer 46 that can be taken in and out of the freezing/thawing chamber 12b and stores food. Specifically, the drawer 46 includes a storage section 46a in which food is stored, and a door section 46b provided in front of the storage section 46a to open and close the freezing/thawing chamber 12b. The housing portion 46a is made of resin material. Furthermore, a metal rail 48 is provided on the inner wall surface of the inner case 42 to guide the drawer 46 when it is put in and taken out. Such a drawer 46 makes it easy to take food in and out of the freezing/thawing chamber 12b.

In the case of this embodiment, as shown in FIGS. 3 and 4, the heating module 40 has a cold air inlet hole for introducing cold air (dotted chain line) into the freezing/thawing chamber 12b inside the heating module 40, and A cold air outlet hole is provided to discharge the cold air inside. Specifically, a plurality of through holes 44a formed in the ceiling of the shield case 44 and a through hole 42a formed in the ceiling of the inner case 42 are provided as cold air inlet holes of the heating module 40. . These through holes 42a and 44a allow the cold air blown by the cooling fan 24, passing through the damper 26B and flowing through the flow path 12g, to be introduced into the freezing/thawing chamber 12b.

A plurality of through holes 42b formed at the bottom of the inner case 42 and a plurality of through holes 44b formed at the bottom of the shield case 44 are provided as cold air outlet holes of the heating module 40. These through holes 42b and 44b allow the cold air in the freezing/thawing chamber 12b to be returned to the cooling chamber 12f.

In addition, in the case of this Embodiment, the cold air which flowed out from the through-holes 42b and 44b as a cold air exit hole returns to 12 f of cooling chambers via the freezing chamber 12c. For this purpose, as shown in FIG. 6, a partition wall 12j in the main body 12 of the refrigerator 10 that separates a space 12h in which the cooling/defrosting chamber 12b is incorporated and a freezing chamber 12c has a through hole that connects the space 12h and the freezing chamber 12c. A hole 12k is provided.

In addition, as shown in FIGS. 4 and 8, the accommodating portion 46a of the drawer 46 has at least one of its bottom and side wall portions so that the cold air in the drawer 46 flows smoothly into the cooling chamber 12f (that is, the freezing chamber 12c). Preferably, the drawer 46 is provided with a through hole 46c penetrating from the inside to the outside. In the case of this embodiment, a plurality of slit holes 46c are provided as the through holes 46c in the rear side wall of the drawer 46, extending in the vertical direction and being lined up in the left and right direction.

In order to thaw the frozen food in the freezing/thawing chamber 12b, the heating module 40 includes a heating section 50, as shown in FIG. 2.

FIG. 9 is a block diagram showing a control system of the heating section of the heating module.

As shown in FIG. 5, the heating module 40 includes, as components of the heating section 50, an oscillation electrode 52 and a counter electrode (counter electrode section) 54 that faces the oscillation electrode 52.

In the case of this embodiment, the oscillation electrode 52 is a flat electrode made of a metal material as shown in FIG. It is located in the space between the Further, the oscillation electrode 52 is formed with a plurality of cold air passage holes 52a through which cold air passes. The cold air passage hole 52a allows the oscillation electrode 52 to be cooled with cold air, and also allows the cold air to be introduced into the region of the freezing/thawing chamber 12b located below the oscillation electrode 52.

In the case of this embodiment, the counter electrode 54 is a portion 44c of the bottom of the shield case 44. Further, the counter electrode 54 (portion 44c) faces the oscillation electrode 52 in the vertical direction with the inner case 42 in between, that is, with the freezing/thawing chamber 12b in between. The oscillation electrode and the counter electrode do not need to have the same area.

As shown in FIG. 9, the heating section 50 includes an oscillation circuit (which applies an AC voltage of a predetermined VHF band frequency, for example, 40.68 MHz, between the oscillation electrode 52 and the counter electrode 54 under the control of the control section 30). oscillation section) 56. Specifically, the oscillation circuit 56 is a circuit formed on a substrate, and is electrically connected to the oscillation electrode 52 and the counter electrode 54. Further, the oscillation circuit 56 converts the AC voltage from the power supply section 58 of the refrigerator 10 connected to a commercial power source, and applies the converted AC voltage between the oscillation electrode 52 and the counter electrode 54.

By applying an alternating voltage, an alternating electric field is generated between the oscillation electrode 52 and the counter electrode 54. This alternating electric field dielectrically heats the food placed between these electrodes 52, 54, that is, the food stored in the drawer 46 in the freeze/thaw chamber 12b. As a result, the frozen food is thawed.

In addition, in the case of this embodiment, as shown in FIGS. 3 and 5, the oscillation electrode 52 and the counter electrode 54 do not face each other across the entire freezing/thawing chamber 12b, but face each other across a part of it. It is arranged so that As a result, the freezing/thawing chamber 12b is divided into the thawing zone (heating zone) DZ (area indicated by broken line cross hatching), which is the space where the food to be thawed (to be heated) is placed, and the thawing zone DZ. On the other hand, it is divided into a non-thawing zone (non-heating zone) NDZ, which is a continuous space and in which foods that are not to be thawed (not to be heated) are placed. That is, a decompression zone DZ exists between the oscillation electrode 52 and the counter electrode 54, and a non-decompression zone NDZ does not exist.

By dividing the freezing/thawing chamber 12b into the thawing zone DZ and the non-thawing zone NDZ in this manner, it is possible to thaw only a portion of the plurality of foods stored in the freezing/thawing chamber 12b. Therefore, when thawing is performed, there is no need to move food that is not desired to be thawed from the freezing/thawing chamber 12b, for example, to the freezing chamber 12c. In addition, if the operation unit 32 is configured to be able to reserve the start time of thawing, the food placed in the thawing zone DZ is maintained in a frozen state until thawing starts, and then the food is automatically thawed. be done.

Moreover, in the case of this embodiment, the defrosting zone DZ is located in front of the refrigerator 10 with respect to the non-defrosting zone NDZ. Therefore, the food thawed in the thawing zone DZ can be taken out immediately.

In order to show the user to place the food to be thawed in the thawing zone DZ, a presentation unit that presents to the user that the portion of the drawer 46 placed in the thawing zone DZ is the place where the food to be thawed is placed. It is preferable to provide The presentation portion may be, for example, an image or text printed on the bottom of the drawer 46. For example, the presentation section may be a partition wall provided in the drawer 46 that indicates the boundary between the thawing zone DZ and the non-thawing zone NDZ. The front-back positional relationship between the defrosting zone DZ and the non-defrosting zone NDZ may be reversed. If the opposite is true, the distance between the connecting members 64 will be shortened, and the heating efficiency will be improved.

As shown in FIG. 8, when the oscillation electrode 52 and the counter electrode 54 are viewed facing each other (in the vertical direction of the refrigerator 10), the oscillation electrode 52 and the counter electrode 54 are attached to the inner case 42 so as not to overlap with the rail 48. Preferably, it is provided. On the other hand, when a rail 48 exists between the oscillation electrode 52 and the counter electrode 54, an alternating electric field is generated between the oscillation electrode 52 and the rail 48, and an alternating electric field is generated between the oscillation electrode 52 and the counter electrode 54. The alternating electric field is weakened, and the uniformity of the electric field (uniformity of heating) is impaired.

Furthermore, in the case of this embodiment, the counter electrode 54 is a raised portion of the shield case 44 that protrudes toward the oscillation electrode 52, so that the counter electrode 54 approaches the oscillation electrode 52. Thereby, a stronger alternating electric field can be generated than when the counter electrode 54 is not a raised portion.

During thawing of the food, that is, when an alternating electric field is generated between the oscillating electrode 52 and the counter electrode 54, the shield case 44 functions as a shielding member to prevent this alternating electric field from leaking to the outside. In order to prevent the alternating electric field from leaking to the outside through the front opening of the shield case 44, a metal shield plate 46d is provided inside the door 46b of the drawer 46, as shown in FIG. The shield plate 46d and the shield case 44 surround and electromagnetically shield the freezing/thawing chamber 12b where an alternating electric field is generated.

As shown in FIG. 9, the heating section 50 also includes a matching circuit (matching section) 60 for impedance matching between the oscillation electrode 52 and the counter electrode 54. Specifically, matching circuit 60 is a circuit formed on a substrate, and is electrically connected to oscillation electrode 52 and counter electrode 54 . In this embodiment, the counter electrode 54 is grounded.

The role of matching circuit 60 will be explained. As food thaws, the amount of water molecules in the food increases. As water molecules increase, the impedance changes from the matched state and the reflectance increases. Note that the reflectance is the ratio of the reflected wave returning to the oscillation circuit 56 to the incident wave output from the oscillation circuit 56.

FIG. 10 is a diagram showing changes in reflectance during thawing of food.

In FIG. 10, P1 to P5 are timings at which the matching circuit 60 re-establishes impedance matching between the oscillation electrode 52 and the counter electrode 54. Further, R1 to R3 are threshold values of reflectance. Furthermore, in reality, a threshold value of reflected power that is easy to detect may be provided in place of the reflectance for determination.

Once the food begins to thaw, the reflectance increases over time. Each time the reflectance reaches the second threshold R2, the matching circuit 60 re-matches the impedance between the oscillation electrode 52 and the counter electrode 54. As a result, the reflectance decreases. In this way, by repeatedly adjusting the impedance matching between the oscillating electrode 52 and the counter electrode 54 until the food is thawed, it is possible to efficiently thaw the food by suppressing loss of electrical energy due to reflection. can.

In order to calculate this reflectance, the heating section 50 includes a reflected wave detection circuit 62, as shown in FIG. The control unit 30, as a reflectance calculation unit, calculates the reflectance based on the incident wave output from the oscillation circuit 60 and the reflected wave detected by the reflected wave detection circuit 62. Each time the calculated reflectance reaches the second threshold R2, the matching circuit 60 re-matches the impedance between the oscillation electrode 52 and the counter electrode 54.

In the case of this embodiment, as shown in FIG. 5, the oscillation circuit 56, the matching circuit 60, and the reflected wave detection circuit 62 are incorporated into the heating module 40. Note that the reflected wave detection circuit 62 is formed on the substrate on which the matching circuit 60 is formed.

Specifically, as shown in FIG. 5, the oscillation circuit 56 and the matching circuit 60 are arranged in a shield chamber 44d provided in the shield case 44. This shield chamber 44d is isolated from the freezing/thawing chamber 12b by a partition wall 44e. By being arranged in such a shield chamber 44d, the oscillation circuit 56 and the matching circuit 60 are shielded from the alternating electric field generated in the freezing/thawing chamber 12b, and malfunctions are suppressed.

Note that the connecting member 64 that electrically connects the matching circuit 60 and the oscillation electrode 52 penetrates the partition wall 44e. Furthermore, as shown in FIG. 8, the connecting member 64 is smaller in size in the left-right direction than the oscillation electrode 52. This is to suppress the generation of an alternating electric field between the connecting member 64 and the portion of the shield case 44 that faces each other with the freezing/thawing chamber 12b in between. That is, as shown in FIG. 3, this is to prevent food present in the non-defrosting zone NDZ located below the connecting member 64 from being thawed.

Further, the oscillation circuit 56 is provided with a connector 66 for connecting to the control section 30 of the refrigerator 10, as shown in FIG. Further, the matching circuit 60 is also provided with a connector 68 for connecting to the control section 30. The connector 66 of the oscillation circuit 56 is provided in the space 12h of the main body 12 of the refrigerator 10 in which the heating module 40 is installed, and engages with a connector 70 connected to the control unit 30, as shown in FIG. Further, the connector 68 of the matching circuit 60 engages with a connector 72 that is similarly provided in the space 12h and connected to the control section 30. Engagement of these connectors is performed through a through hole 12k that communicates the space 12h and the freezer compartment 12c. That is, as shown in FIG. 4, the through hole 12k through which cold air passes from the freezing/thawing chamber 12b to the freezing chamber 12c functions as an access hole for accessing the heating module 40.

The advantage of incorporating the oscillation circuit 56 and the matching circuit 60 (the reflected wave detection circuit 62 included therein) together with the oscillation electrode 52 and the counter electrode 54 into the heating module 40 including the shield case 44 as in this embodiment is as follows. These inspections such as heating tests and noise (alternating electric field) leakage checks can be performed outside the refrigerator 10.

On the other hand, if the oscillation electrode, counter electrode, oscillation circuit, matching circuit, reflected wave detection circuit, and shield parts are each incorporated inside the refrigerator body, a heating test and noise leakage check are performed after all of these are incorporated into the refrigerator body. It is necessary to conduct tests such as: Therefore, for example, if the heating test results are not good or if noise leaks, it is necessary to remove the circuit and shield components built into the refrigerator body, which is very time-consuming. Moreover, if noise leakage occurs, it is necessary to remove the shield member from the refrigerator main body. As a result, refrigerator manufacturing work including inspection may become complicated.

Therefore, by modularizing the oscillation electrode 52, counter electrode 54, oscillation circuit 56, matching circuit 60, reflected wave detection circuit 62, and shield case 44 as the heating module 40, heating tests can be performed outside the refrigerator 10. Since inspections such as noise leakage checks can be performed, manufacturing of the refrigerator 10 becomes easier. Furthermore, if the refrigerator casing is covered with a metal plate, leakage noise may not be detected from outside the refrigerator because it is shielded by the metal plate. In that case, the risk that the electronic components located between the metal plate and the heating module 40 will not operate properly due to the influence of leakage noise is overlooked, and the quality of the refrigerator cannot be confirmed.

Up to this point, the configuration of the freezing/thawing chamber 12b has been described. From here on, the operation (operation) for food in the freezing/thawing chamber 12b of the refrigerator according to the present embodiment will be explained.

In the case of this embodiment, the control unit 30 executes normal operation, rapid cooling operation, zone thawing operation (zone heating operation), all zone thawing operation, and slight freezing operation for the food in the freezing/thawing chamber 12b. do.

In normal operation, in order to preserve the food in the freezing/thawing chamber 12b in a frozen state, the temperature in the freezing/thawing chamber 12b is set to the freezing storage temperature (first cooling storage temperature), for example, the freezing temperature at which the food freezes. The operation is maintained at a temperature of -16°C to -20°C. That is, this is an operation in which the temperature is maintained at approximately the same temperature as that of the freezer compartment 12c.

FIG. 11 is a timing chart of normal operation.

As shown in FIG. 11, during normal operation, the compressor 20 is operated intermittently to maintain the temperature inside the freezing/thawing chamber 12b at the frozen storage temperature Tf (to maintain the food temperature at Tf). At the same time, the cooling fan 24 and damper 26B are controlled.

Due to such intermittent operation of the compressor 20, the moisture in the food evaporates when the compressor 20 is stopped (when OFF), and evaporates when the compressor 20 is operating (when ON). Frost forms on the food, which causes the food temperature to fluctuate widely.

If frost forms on the food placed in the thawing zone DZ, some of the food will dry out, causing freezer burn and deterioration, so even if thawing is performed with high quality, the user will not be able to receive high quality food. cannot be provided.

To deal with this, in the case of the present embodiment, when the compressor 20 is operating, the oscillation circuit 56 is turned on to apply an AC voltage between the oscillation electrode 52 and the counter electrode 54, and the compressor 20 is stopped. When this happens, the oscillation circuit 56 is turned OFF and application of the alternating current voltage is stopped, thereby reducing temperature fluctuations in the food. The output of the oscillation circuit 56 at this time is, for example, 30% or more of the refrigerating capacity.

Such intermittent operation of the oscillation circuit 56 (that is, intermittent dielectric heating) suppresses the formation of frost on the food placed in the thawing zone DZ, and as a result, the occurrence of variations in thawing quality is suppressed. suppressed. Furthermore, expansion of ice crystals inside the food placed in the thawing zone DZ can be suppressed. When ice crystals grow large inside food, they damage the cells and tissues of the food, and when thawed, water flows out from the damaged cells and tissues, reducing the quality of the food. As a countermeasure, dielectric heating can be used to collect an electric field at the tip of the ice crystal, suppressing the elongation of the crystal, and by controlling the size of the ice crystal, it is possible to suppress the physical deterioration of the food.

The rapid cooling operation is an operation for freezing (quickly cooling) the food to be newly frozen when it is placed in the thawing zone DZ of the freezing/thawing chamber 12b more rapidly than in the normal operation. Moreover, when the food is placed, the rapid cooling operation is automatically started.

FIG. 12 is a timing chart of the rapid cooling operation.

The reflectance described above is used to detect that the food to be quickly frozen is placed in the thawing zone DZ of the freeze/thaw chamber 12b. As shown in FIG. 12, the oscillation circuit 56 is weakly operated (low oscillation output) using the signal from the door open/close switch as a trigger, and the closing is determined based on the reflectance. After the injection determination, the oscillation circuit 56 is periodically operated to detect a change in reflectance, the frozen state is determined based on the detected change in reflectance, and the operation of the oscillation circuit 56 is controlled.

As shown in FIG. 12, when the food to be quickly frozen is placed in the thawing zone DZ of the freezing/thawing chamber 12b (timing P6), the reflectance decreases. This is because the dielectric constant between the oscillation electrode 52 and the counter electrode 54 increases because the food to be quickly frozen is placed between the oscillation electrode 52 and the counter electrode 54 .

In the case of the present embodiment, when the reflectance decreases beyond the first threshold value R1, the control unit 30 determines that the food to be quickly frozen is placed in the thawing zone DZ of the freezing/thawing chamber 12b. , a rapid cooling operation is started in place of the normal operation (timing P7).

When the rapid cooling operation is started, cooling control is continuously executed as shown in FIG. 12 . For example, the compressor 20 and the cooling fan 24 are operated continuously, and the damper 26B is maintained in an open state. Note that, if there is surplus power, the output of the compressor 20 and the rotational speed of the cooling fan 24 may be increased compared to during normal operation.

As shown in FIG. 12, when the reflectance decreases and reaches the second threshold value R2, the rate of change in the reflectance increases. This is because the food temperature has entered the maximum ice crystal formation zone (for example, -1 to -5°C) where ice crystals are likely to grow.

When the food temperature enters the maximum ice crystal formation zone (when the reflectance reaches the second threshold value R2), the oscillation circuit 56 of the heating section 50 applies an AC voltage between the oscillation electrode 52 and the counter electrode 54. Start applying it intermittently. At this time, the output of the oscillation circuit 56 is smaller than the output during normal operation, for example, 1 to 10 W. By such dielectric heating by the heating unit 50, the food can be frozen while suppressing the expansion of ice crystals within the food.

When the reflectance further decreases and reaches the third threshold value R3, the rate of change in the reflectance becomes smaller. This is because the food temperature has reached just before passing through the zone of maximum ice crystal formation. When the third threshold value R3 is reached and a predetermined time t1 has elapsed, the control unit 30 determines that the food temperature has passed through the maximum ice crystal generation zone, and the cooling control returns to the control during normal operation, and the oscillation circuit The intermittent application of the AC voltage by 56 ends (timing P8). This ends the rapid cooling operation and returns to normal operation.

The zone thawing operation (zone heating operation) is an operation in which only the food placed in the thawing zone DZ is thawed (heated) and the food placed in the non-thawing zone NDZ is maintained at the frozen storage temperature Tf. The zone thawing operation is different from the quenching operation, and is started when the operation unit 32 receives a user's instruction to switch from normal operation to zone thawing operation. For example, when the user presses a "zone defrost" button on the operation unit 32, a zone defrost operation is started.

FIG. 13 is a timing chart diagram of zone thawing operation.

As shown in FIG. 13, when the zone thawing operation is started, the oscillation circuit 56 of the heating section 50 begins to continuously apply an alternating current voltage between the oscillation electrode 52 and the counter electrode 54. As a result, food A placed in the thawing zone DZ begins to defrost, and the temperature of food A begins to rise.

On the other hand, the output of the compressor 20 is adjusted so as to maintain the food B placed in the non-thawing zone NDZ at the frozen storage temperature Tf, that is, to maintain the freezing/thawing chamber 12b at the frozen storage temperature Tf during normal operation. , the rotation speed of the cooling fan 24, and opening/closing of the damper 26B are controlled. For example, the damper 26B repeats opening and closing so that the open state and the closed state continue for the same amount of time.

Thereby, food B placed in the non-thawing zone NDZ is frozen and preserved in the same way as during normal operation. In the case of this zone thawing operation, the output of the compressor 20 and the rotation speed of the cooling fan 24 are higher than during normal operation, considering the temperature rise in the freezing/thawing chamber 12b caused by dielectric heating by the heating section 50. , and the damper 26B is open for a long time.

Further, according to such zone thawing operation, water vapor generated from the food A being thawed is discharged to the outside of the cooling/thawing chamber 12b by intermittently opening the damper 26B. As a result, the relative humidity in the cooling/thawing chamber 12b does not reach 100%, and frost formation is suppressed.

When food A placed in the thawing zone DZ is thawed, the zone thawing operation ends.

Note that in the case of this embodiment, completion of defrosting of food is determined based on a change in reflectance.

Looking at FIG. 10, which shows changes in reflectance during food thawing, as thawing progresses, the reflectance immediately after impedance matching gradually increases. For example, the reflectance at timing P2 is higher than the reflectance at timing P1. At timing P5, unlike the previous timings P1 to P4, the reflectance after impedance matching is higher than the third threshold value R3. By appropriately setting this third threshold R3, if the reflectance reduced by impedance matching is higher than the third threshold R3, the impedance matching execution timing P5 is regarded as the decompression end timing. be able to. Therefore, if the reflectance does not decrease beyond the third threshold due to impedance matching, the control unit 30 determines that the food has been thawed at the impedance matching execution timing, and ends the zone thawing operation. When zone thawing operation is finished, normal operation returns. However, depending on the amount and physical properties of the food, the reflectance after matching may exceed R3 even if the food is not thawed, or may not reach R2 even after thawing is complete. Therefore, the minimum driving time and the maximum driving time may be set regardless of the threshold values R2 and R3.

The all-zone thawing operation is an operation in which all foods in the freezing/thawing chamber 12b are thawed (heated), that is, not only foods in the thawing zone DZ but also foods in the non-thawing zone NDZ. Similar to the zone thawing operation, the all-zone thawing operation is also started when the operation unit 32 receives a user's instruction to switch from the normal operation to the all-zone thawing operation. For example, when the user presses the "all zones defrost" button on the operation unit 32, all zones defrost operation is started.

FIG. 14 is a timing chart of the all-zone defrosting operation.

As shown in FIG. 14, the all-zone thawing operation is the same as the zone thawing operation shown in FIG. 12, except for the opening time of the damper 26B. Specifically, during the all-zone thawing operation, the damper 26B is generally closed in order to maintain the temperature of the freezing/thawing chamber 12b, which increases due to the dielectric heating of the heating section 50. However, the damper 26B momentarily opens to discharge water vapor to the outside in order to reduce the humidity in the cooling/thawing chamber 12b and suppress the formation of frost. Through such all-zone thawing operation, all the foods in the cooling/thawing chamber 12b are thawed. The all-zone thawing operation also ends in the same way as the zone thawing operation. After that, normal operation will resume.

The slight freezing operation is an operation performed when the food after thawing (thawed food) is left as it is without being taken out from the cooling/thawing chamber 12b.

If the thawed food is thawed by the zone thawing operation or the all-zone thawing operation and is left as is, it will be frozen again by the subsequent normal operation. Therefore, there is a possibility that the user takes out the thawed food from the freezing/thawing chamber 12b in a refrozen state. Naturally, due to its refrozen condition, it is hard and the user cannot immediately cook the food. One possible solution to this problem is to maintain the temperature of the thawed food at a temperature that will not freeze it after thawing, but in that case, the thawed food may be damaged if left for a long period of time.

Therefore, in the case of this embodiment, if the thawed food is left as it is without being taken out from the cooling/thawing chamber 12b, the thawed food is compared to the frozen storage temperature (-16°C to -20°C). High cooling storage temperature (maintaining at a second cooling storage temperature, for example, micro-freezing operation (second cooling storage) in which thawed food is maintained at a slight freezing temperature (for example, -3°C to -7°C) to a slightly frozen state. The "slight freezing state" referred to here refers to a state in which the liquid inside the cells of the food does not freeze, but the liquid outside the cells freezes.

Note that the slight freezing operation performed after the zone thawing operation (zone slight freezing operation) and the slight freezing operation carried out after the all zone thawing operation (all zone slight freezing operation) are different in content.

After the zone thawing operation, a zone slight freezing operation is performed. This operation is an operation in which the temperature in the freezing/thawing chamber 12b is maintained at the frozen storage temperature, and the heating section 50 heats the thawed food in the thawing zone DZ so that the temperature thereof is maintained at the slightly freezing temperature. . As a result, the thawed food in the thawing zone DZ is maintained at a slightly freezing temperature, while the food in the non-thawing zone NDZ is maintained at a frozen storage temperature as in normal operation.

After the all-zone thawing operation, the all-zone thawing operation is executed. This operation is an operation in which the temperature in the freezing/thawing chamber 12b is maintained at a slightly freezing temperature while the heating section 50 is stopped. Thereby, the thawed food in the freezing/thawing chamber 12b is maintained at a slightly freezing temperature.

In order to perform the zone and all-zone slight freezing operation, a thawed food detection unit (heated food detection unit) that detects whether or not thawed food exists in the freezing/thawing chamber 12b after thawing is completed. is necessary.

In the case of this embodiment, the presence of thawed food is detected using the reflectance described above. That is, the reflected wave detection circuit 62 that detects reflected waves and the control section 30 that calculates the reflectance based on the detected reflected waves function as a thawed food detection section.

Specifically, as explained in the rapid cooling operation, when food to be frozen is placed in the thawing zone DZ, the reflectance decreases beyond the first threshold value R1. From the opposite point of view, when the thawed food is removed from the thawing zone DZ, the reflectance rises above the first threshold R1. Therefore, if the reflectance rises above the first threshold value R1, it can be determined that the thawed food thawed by the zone thawing operation has been removed from the thawing zone DZ, or if the thawed food is thawed by the all-zone thawing operation. It can be determined that the food has been taken out from the thawing zone DZ and the non-thawing zone NDZ.

When the presence of thawed food is detected in the freezing/thawing chamber 12b after thawing, a zone or all-zone slight freezing operation is executed. If the presence of food is not detected, normal operation is performed.

Alternatively, as shown in FIG. 3, the presence of thawed food may be detected by a door sensor 34 that detects opening/closing of the door of the cooling/thawing chamber 12b (door portion 46b of the drawer 46).

In order to take out the thawed food from the freezing/thawing chamber 12b, the user must open the door. Therefore, if the door sensor 34 does not detect the opening of the door after thawing is completed, it can be determined that thawed food is present in the freezing/thawing chamber 12b.

Further details of the zone slight freezing operation and the all zone slight freezing operation will be explained using the flowchart shown in FIG. 15.

As shown in FIG. 15, first, when the zone (all zones) thawing operation ends, in step S100, the control unit 30 starts the zone (all zones) slight freezing operation.

In step S110, the control unit 30 determines whether food is present in the freezing/thawing chamber 12b. If it exists, the process advances to step S120. If not, the process advances to step S140.

In step S120, the control unit 30 determines whether the food detected in step S110 is a thawed food. This is because there is a possibility that the food detected in step S110 is food that has been stored in the freezing/thawing chamber 12b and will be frozen in the future. However, if the food detected in step S110 is a food that is to be frozen, the door of the freezing/thawing chamber 12b has been opened by the user after thawing is completed. That is, the door sensor 34 detects the opening of the door after the defrosting is completed. Therefore, if the door sensor 34 does not detect the opening of the door, it is determined that the food detected in step S110 is a thawed food, and the process proceeds to step S130. If not, it is determined that the food detected in step S110 is a food that will be frozen, the process proceeds to step S160, the zone (all zones) slight freezing operation is ended, and the rapid cooling operation is started in the following step S170. .

If it is determined in step S120 that the food is thawed, then in step S130 the control unit 30 determines whether a predetermined period of time has elapsed since the end of thawing. This is because if thawed foods are stored in a slightly frozen state for a long period of time, their quality will deteriorate. In the case of all-zone thawing operation, the predetermined period is, for example, seven days. In the case of zone thawing operation, frost is more likely to occur than in all-zone thawing operation, so the predetermined period is five days, which is shorter than in all-zone thawing operation. If a predetermined period of time has elapsed since the end of thawing, the process proceeds to step S140, where the zone (all zones) slight freezing operation is ended, and normal operation is started at subsequent step S150. If the predetermined period has not elapsed, the process returns to step S110.

As described above, according to the present embodiment, in a refrigerator equipped with a freezing/thawing chamber capable of freezing and thawing food, it is possible to appropriately preserve thawed food that has been thawed in the freezing/thawing chamber and left as is. I can do it.

Although the present invention has been described above with reference to the above embodiments, the present invention is not limited to the above embodiments.

For example, in the case of the above embodiment, as shown in FIG. 5, the cooling/thawing chamber 12b is divided into a thawing zone DZ and a non-thawing zone NDZ. That is, the oscillation electrode 52 and the counter electrode 54 are arranged to face each other with a part of the cooling/thawing chamber 12b interposed therebetween. However, embodiments of the present invention are not limited to this. The oscillation electrode and the counter electrode may be arranged to face each other across the entire cooling/thawing chamber. That is, the entire cooling/thawing chamber may be a thawing zone in which food can be thawed by dielectric heating.

Further, in the case of the above-described embodiment, the method of heating and defrosting the food is dielectric heating using an oscillating electrode and a counter electrode, but the embodiment of the present invention is not limited to this. For example, it may be a sheathed heater.

Furthermore, in the case of the above-described embodiment, completion of defrosting of food is determined based on reflectance. However, embodiments of the present invention are not limited to this. For example, the user may set the defrosting time, and the timing at which the defrosting time has elapsed from the start of defrosting may be the timing at which the defrosting of the food ends. In this case, the operation unit is configured to receive a user's instruction to start defrosting and to input a defrosting time.

Furthermore, in the case of the above embodiment, as shown in FIG. 4, the housing chamber of the heating module 40 functions as a freezing/thawing chamber 12b capable of freezing and thawing by introducing cold air. However, the embodiments of the present invention are not limited to this. The heating module may not introduce cold air into its storage chamber, ie it may be used only for defrosting. The heating module 40 may be used not only for freezing and defrosting, but also for cooling and heating food as temperature control. That is, the housing chamber for the heating module 40 may be a cooling/heating chamber.

In addition, in the above embodiment, the explanation was mainly given of an example in which the food is thawed by heating in the freezing room, but it is also possible to heat the food in a room with a temperature range other than that in the refrigerator. For example, by heating milk to which yogurt bacteria is added or soybeans to which natto bacteria is added, which are stored in a refrigerator, fermentation can be promoted to make homemade yogurt or natto.

A person skilled in the art will appreciate that it is possible to combine at least a part of one embodiment with at least one other embodiment in whole or in part to obtain a further embodiment of the present invention. It is obvious for

INDUSTRIAL APPLICATION This invention is applicable to a refrigerator provided with a heating function.

10 Refrigerator 12b Freezing/thawing room

Claims (8)

A refrigerator equipped with a cooling/heating chamber capable of cooling and heating food, the refrigerator comprising:
a heating section that heats the food by heating the inside of the cooling/heating chamber;
a heated food detection unit that detects whether heated food is present in the cooling/heating chamber after heating the food;
The heating section includes an oscillation electrode and a counter electrode arranged to face each other, and an oscillation section that applies an AC voltage between the oscillation electrode and the counter electrode to heat the food therebetween,
Based on the detection result of the heated food detection unit, changing the cooling temperature of the cooling operation of the cooling/heating chamber,
The cooling/heating chamber is divided into a heating zone, which is a space in which food to be heated is placed, and a non-heating zone, which is a space continuous with the heating zone, in which food to be heated is placed. ,
The oscillation electrode and the counter electrode are arranged to face each other across the heating zone of the cooling/heating chamber,
If the heated food is not detected by the heated food detection unit, performing a normal operation in which the cooling temperature of the cooling operation of the cooling/heating chamber is maintained at a first cooling storage temperature;
When the heated food is detected by the heated food detection section, heating the heated food by the heating section while maintaining the cooling/heating chamber at the first cooling storage temperature, A refrigerator that maintains the heated food at a second chilled storage temperature that is higher than the first chilled storage temperature.
The refrigerator according to claim 1, wherein when a predetermined period of time has elapsed from the end of heating, the second cooling storage operation in which the second cooling storage temperature is maintained is switched to the normal operation.
The heated food detection unit includes a reflected wave detection unit that detects a reflected wave returning to the oscillation unit, and a reflectance calculation unit that calculates a reflectance that is a ratio of the reflected wave to the incident wave output from the oscillation unit. including;
The heated food detection unit is configured to set the reflectance to a first threshold value that is smaller than a value when the heated food is not present between the oscillation electrode and the counter electrode. The refrigerator according to claim 1 or 2, wherein the heated food is detected when the heated food is small.
a door for opening and closing the cooling/heating chamber;
A door sensor that detects opening and closing of the door,
The refrigerator according to claim 1 or 2, wherein the heated food detection unit detects the heated food when the door opening/closing sensor does not detect opening of the door after heating is completed.
While the heating section is heating the food, when the reflectance increases and reaches a second threshold value that is smaller than the first threshold value, the oscillation electrode and the opposing It has a matching part that performs impedance matching with the electrode,
If the impedance matching does not reduce the reflectance beyond a third threshold, which is a smaller value than the second threshold, the impedance matching execution timing is set as the end timing of heating the food. , The refrigerator according to claim 3.
an operation unit for receiving a user's instruction to start heating and for the user to input a heating time;
The refrigerator according to any one of claims 1 to 3, wherein the timing at which the heating time has elapsed from the timing at which the start instruction was received is the timing at which the heating of the food ends.
The refrigerator according to claim 1, wherein the first cold storage temperature is a freezing temperature.
The refrigerator according to claim 1, wherein the second cold storage temperature is a slight freezing temperature.

Images