JP2020067214A - refrigerator - Google Patents

Abstract

To provide a structure that facilitates manufacturing of a refrigerator capable of thawing food.SOLUTION: A refrigerator 10 capable of heating food comprises a shield case 44 made of a material including metal, an oscillating electrode 52 provided in the shield case 44, and an opposite electrode 54 arranged so as to be opposite to the oscillating electrode 52. The opposite electrode 54 is formed integrally with the shield case 44.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a refrigerator and a heating module capable of thawing food.

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

JP, 2002-147919, A

  By the way, when food is dielectrically heated as in Patent Document 1, a component for generating an alternating electric field necessary for the dielectric heating and a component for shielding the alternating electric field from leaking to the outside of the refrigerator are incorporated in the body of the refrigerator. I need to go out. In addition, it is necessary to perform inspections such as a heating test and a noise (alternating electric field) leak check after assembling these in the refrigerator body. Therefore, for example, when the result of the heating test is not good or noise leakage occurs, it is necessary to remove the components incorporated in the inside of the refrigerator body, which is very troublesome. As a result, manufacturing work including inspection may be complicated.

  Therefore, it is an object of the present invention to provide a structure that facilitates the manufacture of a refrigerator that can defrost food.

According to one aspect of the present invention,
A refrigerator that can heat food,
A shield case made of a material containing metal,
An oscillation electrode provided in the shield case,
A counter electrode arranged to face the oscillation electrode,
There is provided a refrigerator in which the counter electrode is integrally formed with the shield case.

According to another aspect of the present invention,
An inner case made of an insulating material and defining a storage chamber in which food is stored;
A shield case made of a material containing a metal, integrally provided with a counter electrode, and storing the inner case;
There is provided a heating module having an oscillation electrode arranged between the inner case and the shield case so as to face the counter electrode of the shield case with the inner case sandwiched therebetween.

  ADVANTAGE OF THE INVENTION According to this invention, the structure which facilitates manufacture of the refrigerator which can defrost foodstuffs can be provided.

Vertical sectional view of a refrigerator according to an embodiment of the present invention Block diagram showing the control system of the refrigerator Enlarged sectional view of the freeze / thaw chamber Enlarged sectional view of the freeze / thaw chamber showing the flow of cold air Cross section of heating module Sectional view of a portion of the body of the refrigerator before incorporating the expansion module Exploded sectional view of heating module Sectional drawing of the heating module along the AA line of FIG. Block diagram showing the control system of the heating unit of the heating module Diagram showing changes in reflectance during food thawing Timing chart of normal operation Timing chart of rapid cooling operation Timing chart of zone defrosting operation Timing chart of all zone defrosting operation Flow chart of zone defrosting operation (all zone defrosting operation)

  A refrigerator according to an aspect of the present invention is a refrigerator that can heat food, and includes a shield case made of a material containing a metal, an oscillation electrode provided in the shield case, and a surface facing the oscillation electrode. And a counter electrode arranged as described above, and the counter electrode is formed integrally with the shield case.

  According to such an aspect, it is possible to provide a structure that facilitates the manufacture of a refrigerator capable of thawing food.

  For example, the refrigerator has an inner case that is made of an insulating material, defines an accommodation chamber that accommodates food, and has an inner case that is accommodated in the shield case, and the oscillation electrode is opposite to the counter electrode of the shield case. It may be arranged between the inner case and the shield case so as to face each other with the inner case sandwiched therebetween. As a result, the oscillation electrode is protected by the inner case.

  For example, the refrigerator includes an oscillating unit that applies an AC voltage between the oscillating electrode and the counter electrode, and a matching unit that performs impedance matching between the oscillating electrode and the counter electrode, At least one of the oscillation unit and the matching unit may be provided in the shield case. This makes it easier to manufacture the refrigerator.

  For example, in the heating module, a cold air inlet hole that penetrates the shield case and the inner case to introduce cold air into the accommodation chamber, and a cold air inside the accommodation chamber that penetrates the shield case and the inner case. A cool air outlet hole for discharging may be provided. Thereby, the accommodation chamber of the heating module can also be used as a freezing chamber.

  For example, the oscillation electrode may be provided with a cold air passage hole through which cold air passes. Thereby, the oscillation electrode can be cooled.

  For example, the oscillating electrode and the counter electrode may face each other with a part of the storage chamber interposed therebetween. Accordingly, the space of the storage chamber sandwiched between the oscillation electrode and the counter electrode portion can be used as a thawing zone for thawing food, and the remaining space can be used as a non-thawing zone for thawing food.

  For example, the shield case may include a drawer that is put in and taken out from the storage chamber and stores the food, and a rail that is provided on an inner wall surface of the inner case and guides the drawer. This makes it easy to take food in and out of the storage chamber.

  For example, when viewed from the opposite direction of the oscillation electrode and the counter electrode, the oscillation electrode and the counter electrode are provided in the inner case so as not to overlap the rail. This suppresses dielectric heating of the rail.

  For example, the counter electrode may be a raised portion of the shield case that is raised toward the front oscillation electrode. As a result, the counter electrode approaches the oscillation electrode, and a strong alternating electric field can be generated between them.

  For example, the shield case is provided above the other room, connects the space of the main body of the refrigerator in which the heating module is incorporated with the other room, and allows access to the heating module from the other room. May be provided. This facilitates the incorporation of the heating module into the refrigerator body.

  A heating module according to another aspect of the present invention includes an inner case that is made of an insulating material and defines a storage chamber that stores food, and a material that includes a metal. The inner case is integrally provided with a counter electrode. And a oscillating electrode disposed between the inner case and the shield case so as to face the counter electrode of the shield case with the inner case sandwiched therebetween.

  According to such an aspect, it is possible to provide a structure that facilitates the manufacture of a refrigerator capable of thawing food.

  Hereinafter, a refrigerator according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of the refrigerator according to the present 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. 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 is made of a metal material and forms an outer surface of the refrigerator 10, and an outer housing 14, an inner housing 16 that is made of a resin material such as ABS and forms an inner surface of the refrigerator 10, and an outer housing. The space between the body 14 and the inner casing 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 (foodstuffs, processed foods, etc.). In the case of the present embodiment, as the storage chambers, a refrigerating chamber 12a, a freezing / thawing chamber 12b, a freezing chamber 12c, and a vegetable chamber 12d are provided from the top. Although not shown, an ice making chamber in which ice is made is provided on the right side (the inner side of the drawing) of the freezing / thawing chamber 12b. The refrigerator 10 can also store articles other than food.

  The refrigerating room 12a is a space maintained in a temperature zone where food does not freeze, for example, a temperature zone of 1 ° C to 5 ° C. The freezer compartment 12c is a space maintained in a temperature zone in which food is frozen, for example, in a temperature zone of -22 ° C to -15 ° C. The vegetable compartment 12d is a space maintained at a temperature zone 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 the present embodiment, a machine room 12e is provided above the main body 12 of the refrigerator 10. The machine room 8 accommodates a compressor 20 that constitutes a refrigeration cycle of the refrigerator 10 and circulates the refrigerant of the refrigeration cycle. Alternatively, the machine room 12e may be provided in the lower portion of the main body 12 of the refrigerator 10.

  In the case of the present embodiment, a cooling chamber 12f is provided on the back side of the freezing chamber 12c and the vegetable chamber 12d. Inside the cooling chamber 12f, a cooler 22 that constitutes a refrigeration cycle of the refrigerator 10 and through which a refrigerant passes is arranged. In addition, a cooling fan 24 that blows air (cool air) cooled by the cooler 22 toward the refrigerating room 12a, the freezing / thawing room 12b, the freezing room 12c, and the vegetable room 12d is supplied to the cooling room 12f. It is provided. Further, as shown in FIG. 2, dampers 26A to 26D that control the flow rates of the cool air flowing into the chambers 12a to 12d are arranged in the flow path between the chambers 12a to 12d and the cooling fan 24 (FIG. 1 only the damper 26B is shown).

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

  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 each of the dampers 26A to 26D are controlled to be opened and closed, whereby the temperatures in the refrigerator compartment 12a, the freezing / thawing compartment 12b, the freezing compartment 12c, and the vegetable compartment 12d are appropriately maintained. The control unit 30 is a board provided with a processor such as a CPU, a storage device such as a memory for storing programs, and a circuit, and the processor is a compressor 20 or a cooling fan according to the programs stored in the storage device. 24 and the dampers 26A to 26D are controlled.

  As shown in FIG. 2, in the case of the present embodiment, the refrigerator 10 includes an operating unit 32 for operating the refrigerator 10 by the user, particularly for operating the freezing / thawing chamber 12b. The operation unit 32 may be a touch panel incorporated in the refrigerator 10 and / or a user's mobile terminal. When the operation unit 32 is a mobile terminal, software (application) for operating the refrigerator 10 is installed in the mobile terminal. Details of the freezing / thawing chamber 12b will be described below.

  FIG. 3 is an enlarged cross-sectional view of the freezing / thawing chamber 12b. FIG. 4 is an enlarged sectional view of the freezing / thawing chamber 12b showing the flow of cold air. The flow of cold air is indicated by the alternate long and short dash line.

  As shown in FIG. 3, in the case of the present embodiment, the freezing / thawing chamber 12b is configured by the heating module 40 incorporated in the main body 12 of the refrigerator 10.

  5 is a cross-sectional view of the heating module, and FIG. 6 is a cross-sectional view of a part of the main body of the refrigerator before the heating module is incorporated. FIG. 7 is an exploded sectional view of the heating module. FIG. 8 is a cross-sectional view of the heating module taken along the line AA of 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. The shield case 44 functions as a housing of the heating module 40. The inner case 42 defines a storage chamber in which food is stored, that is, a freezing / thawing chamber 12b.

  The inner case 42 is made of an insulating material such as resin and has a box shape having an opening on the front side. The shield case 44 is made of a material containing metal, and is made of a metal material such as aluminum. Further, the shield case 44 has a box shape having an opening on the front side and storing the inner case 42.

  In the case of the present embodiment, as shown in FIG. 7, the heating module 40 includes a drawer 46 that is put in and taken out from the freezing / thawing chamber 12b and stores food. Specifically, the drawer 46 includes a storage portion 46a in which food is stored, and a door portion 46b that is provided in front of the storage portion 46a and that opens and closes the freezing / thawing chamber 12b. The housing portion 46a is made of a resin material. Further, a metal rail 48 for guiding the drawer 46 at the time of taking in and out is provided on the inner wall surface of the inner case 42. Such a drawer 46 makes it easy to put food in and out of the freezing / thawing chamber 12b.

  In the case of the present embodiment, as shown in FIGS. 3 and 4, the heating module 40 has a cold air inlet hole for introducing cold air (dashed line) into the freezing / thawing chamber 12b therein and the freezing / thawing chamber 12b. A cold air outlet hole for discharging the cold air therein is provided. Specifically, as the cold air inlet holes of the heating module 40, a plurality of through holes 44a formed in the ceiling portion of the shield case 44 and a through hole 42a formed in the ceiling portion of the inner case 42 are provided. . By these through holes 42a and 44a, it is possible to introduce cool air, which is blown by the cooling fan 24, passes through the damper 26B and flows through the flow path 12g, into the freezing / thawing chamber 12b.

  As the cooling air outlet holes of the heating module 40, 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. By these through holes 42b and 44b, the cold air in the freezing / thawing chamber 12b can be returned to the cooling chamber 12f.

  In the case of the present embodiment, the cold air flowing out from the through holes 42b and 44b as the cold air outlet holes returns to the cooling chamber 12f via the freezing chamber 12c. Therefore, as shown in FIG. 6, the partition wall 12j in the main body 12 of the refrigerator 10 separating the space 12h in which the cooling / thawing chamber 12b is incorporated and the freezing chamber 12c is penetrated to connect the space 12h and the freezing chamber 12c. A hole 12k is provided.

  Further, as shown in FIGS. 4 and 8, the accommodating portion 46a of the drawer 46 has at least one of a bottom portion and a side wall portion thereof so that the cool air in the drawer 46 can smoothly flow into the cooling chamber 12f (that is, the freezing chamber 12c). Further, it is preferable to provide a through hole 46c penetrating from the inside of the drawer 46 toward the outside. In the case of the present embodiment, as the through holes 46c, a plurality of slit holes 46c that extend in the up-down direction and are arranged in the left-right direction are provided in the rear side wall portion of the drawer 46.

  As shown in FIG. 2, the heating module 40 includes a heating unit 50 for thawing the frozen food in the freezing / thawing chamber 12b.

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

  As shown in FIG. 5, the heating module 40 includes an oscillating electrode 52 and a counter electrode (counter electrode part) 54 that faces the oscillating electrode 52, as constituent elements of the heating unit 50.

  In the case of the present embodiment, the oscillation electrode 52 is a plate-shaped electrode made of a metal material as shown in FIG. 8, and the ceiling part of the inner case 42 and the ceiling of the shield case 44 as shown in FIG. It is located in the space between the department. Further, the oscillation electrode 52 has 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 by the 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 the present embodiment, the counter electrode 54 is a part 44c of the bottom of the shield case 44. The counter electrode 54 (portion 44c) is vertically opposed to the oscillation electrode 52 with the inner case 42, that is, the freezing / thawing chamber 12b interposed therebetween. The oscillation electrode and the counter electrode do not have to have the same area.

  As shown in FIG. 9, the heating unit 50 is controlled by the control unit 30 to apply an AC voltage of a predetermined VHF band frequency, for example, 40.68 MHz, between the oscillation electrode 52 and the counter electrode 54. The oscillator 56). Specifically, the oscillation circuit 56 is a circuit formed on the 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 unit 58 of the refrigerator 10 connected to the commercial power supply and applies the converted AC voltage between the oscillation electrode 52 and the counter electrode 54.

  By applying the AC 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 arranged between the electrodes 52 and 54, that is, the food contained in the drawer 46 in the freezing / thawing chamber 12b. As a result, the frozen food is thawed.

  In the case of the present 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 thereof. It is arranged to. As a result, the freezing / thawing chamber 12b is continuous with the thawing zone DZ (the area indicated by the cross-hatching of broken lines), which is the space in which the food to be thawed (heated) is placed. It is a space and is divided into a non-thaw zone NDZ in which a non-thaw target (non-heat target) food is placed. That is, the thawing zone DZ exists and the non-thawing zone NDZ does not exist between the oscillation electrode 52 and the counter electrode 54.

  By thus dividing the freezing / thawing chamber 12b into the thawing zone DZ and the non-thawing zone NDZ, it is possible to thaw only a part of the plurality of foods stored in the freezing / thawing chamber 12b. Therefore, when thawing, it is not necessary to move food that is not desired to be thawed from the freezing / thawing chamber 12b, for example, to the freezing chamber 12c. Further, when 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 kept in a frozen state until thawing is started, and then automatically thawed. To be done.

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

  In order to indicate to the user that the food to be defrosted is placed in the defrosting zone DZ, a presentation unit that presents to the user that the portion of the drawer 46 placed in the defrosting zone DZ is the place to place the food to be defrosted. Is preferably provided. The presentation unit may be, for example, an image or characters printed on the bottom surface of the drawer 46. Further, for example, the presentation unit may be a partition wall provided in the drawer 46, which indicates the boundary between the thawing zone DZ and the non-thawing zone NDZ. The front-rear positional relationship between the defrosting zone DZ and the non-defrosting zone NDZ may be reversed. In the opposite case, the distance of the connecting member 64 is shortened and the heating efficiency is improved.

  As shown in FIG. 8, when the oscillation electrode 52 and the counter electrode 54 are opposed to each other (in the vertical direction of the refrigerator 10), the oscillation electrode 52 and the counter electrode 54 are arranged in the inner case 42 so as not to overlap the rail 48. It is preferably provided. On the other hand, when the rail 48 is present 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 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.

  Further, in the case of the present embodiment, the counter electrode 54 is a raised portion of the shield case 44 that is raised toward the oscillation electrode 52, and thus the counter electrode 54 is close to the oscillation electrode 52. As a result, a stronger alternating electric field can be generated as compared with the case where the counter electrode 54 is not a raised portion.

  During thawing of food, that is, when an alternating electric field is generated between the oscillation electrode 52 and the counter electrode 54, the shield case 44 functions as a shield member that shields the alternating electric field from leaking to the outside. As shown in FIG. 5, a metallic shield plate 46d is provided in the door portion 46b of the drawer 46 so that the alternating electric field does not leak to the outside through the opening on the front side of the shield case 44. The shield plate 46d and the shield case 44 surround and electromagnetically shield the freezing / thawing chamber 12b in which an alternating electric field is generated.

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

  The role of the matching circuit 60 will be described. As the food is thawed, the number of water molecules in the food increases. As the number of water molecules increases, the impedance changes from the matched state and the reflectance increases. 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 when the matching circuit 60 re-establishes impedance matching between the oscillation electrode 52 and the counter electrode 54. R1 to R3 are reflectance threshold values. In reality, instead of the reflectance, a threshold value of reflected power that is easy to detect may be provided for the determination.

  When the food is thawed, the reflectance increases with time. Each time the reflectance reaches the second threshold value R2, the matching circuit 60 re-establishes impedance matching between the oscillation electrode 52 and the counter electrode 54. As a result, the reflectance decreases. By repeatedly re-adjusting the impedance matching between the oscillation electrode 52 and the counter electrode 54 before the thawing of food is completed in this way, the loss of electric energy due to reflection can be suppressed and the food can be thawed efficiently. it can.

  In order to calculate this reflectance, the heating unit 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 value R2, the matching circuit 60 re-establishes impedance matching between the oscillation electrode 52 and the counter electrode 54.

  In the case of the present embodiment, as shown in FIG. 5, the oscillation circuit 56, the matching circuit 60, and the reflected wave detection circuit 62 are incorporated in the heating module 40. 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. The shield chamber 44d is separated 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 malfunction is suppressed.

  The connecting member 64 that electrically connects the matching circuit 60 and the oscillation electrode 52 penetrates the partition wall 44e. Further, as shown in FIG. 8, the size of the connecting member 64 in the left-right direction is smaller than that of 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 the freezing / thawing chamber 12b. That is, as shown in FIG. 3, this is to prevent the food present in the non-thawing zone NDZ located below the connecting member 64 from being thawed.

  Further, the oscillator circuit 56 is provided with a connector 66 for connecting to the control unit 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 unit 30. As shown in FIG. 6, 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 incorporated, and engages with the connector 70 connected to the control unit 30. In addition, the connector 68 of the matching circuit 60 engages with the connector 72 that is also provided in the space 12h and connected to the control unit 30. The engagement work of these connectors is performed through a through hole 12k that connects the space 12h and the freezer compartment 12c. That is, as shown in FIG. 4, the through hole 12k through which cold air flowing from the freezing / thawing chamber 12b to the freezing chamber 12c passes serves as an access hole for accessing the heating module 40.

  As in the present embodiment, 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 in the heating module 40 including the shield case 44 is as follows. It is possible to perform inspections such as these heating tests and noise (alternating electric field) leakage checks outside the refrigerator 10.

  On the contrary, when the oscillation electrode, the counter electrode, the oscillation circuit, the matching circuit, the reflected wave detection circuit, and the shield component are installed inside the refrigerator body, the heating test and the noise leakage check are performed after they are all installed in the refrigerator body. It is necessary to perform inspections such as. Therefore, for example, when the result of the heating test is not good or when the noise leakage occurs, it is necessary to remove the circuit and the shield component built in the inside of the refrigerator body, which is very troublesome. Moreover, when noise leakage occurs, it is necessary to remove the shield member from the refrigerator body. As a result, the work of manufacturing the refrigerator including the inspection may be complicated.

  Therefore, by modularizing the oscillation electrode 52, the counter electrode 54, the oscillation circuit 56, the matching circuit 60, the reflected wave detection circuit 62, and the shield case 44 as the heating module 40 in this way, it is possible to perform a heating test outside the refrigerator 10. Since the inspection such as the noise leakage check can be performed, the refrigerator 10 can be easily manufactured. Moreover, when the refrigerator housing is covered with a metal plate, there is a possibility that leakage noise cannot be detected from the outside because it is shielded by the metal plate. In that case, the risk that the electronic components between the metal plate and the heating module 40 do not operate normally 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, the operation (operation) for the food in the freezing / thawing chamber 12b of the refrigerator according to the present embodiment will be described.

  In the case of the present embodiment, the control unit 30 performs the normal operation, the rapid cooling operation, the zone thawing operation, the all-zone thawing operation, and the slight freezing operation on the food in the freezing / thawing chamber 12b.

  The normal operation is an operation of maintaining the temperature in the freezing / thawing chamber 12b at a frozen storage temperature, for example, -16 ° C to -20 ° C, in order to store the food in the freezing / thawing chamber 12b in a frozen state. That is, it is an operation of maintaining the temperature at the same level as the freezer compartment 12c.

  FIG. 11 is a timing chart of normal operation.

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

  Due to such intermittent operation of the compressor 20, when the compressor 20 is stopped (when OFF), the water content of the food is evaporated, and when the compressor 20 is operating (when ON). The food is frosted, which causes the food temperature to fluctuate widely.

  When the food placed in the thawing zone DZ gets frosted, a part of the food is dried and freezes and deteriorates. Therefore, even if the thawing is performed at a high quality, the user can obtain a high quality food. I cannot provide it.

  As a countermeasure, 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. During this time, the oscillation circuit 56 is turned off to stop the application of the AC voltage, thereby reducing the temperature fluctuation of the food. The output of the oscillation circuit 56 at this time is, for example, 30% or more of the refrigerating capacity.

  Due to such intermittent operation of the oscillation circuit 56 (that is, intermittent dielectric heating), it is possible to suppress frost from being generated in the food arranged in the thawing zone DZ, and as a result, thawing quality varies. Suppressed. In addition, it is possible to suppress the expansion of ice crystals inside the food arranged in the thawing zone DZ. When ice crystals are greatly extended inside the food, the cells and tissues of the food are damaged, and water is leaked from the damaged cells and tissues during thawing, which deteriorates the quality of the food. As a countermeasure against this, an electric field is collected at the tip of the ice crystal by dielectric heating to suppress the elongation of the crystal, and the size of the ice crystal can be suppressed to prevent physical deterioration of the food.

  The rapid cooling operation is an operation for freezing (quickly cooling) the food, which is to be newly frozen from now on, when the food is placed in the defrosting zone DZ of the freezing / thawing chamber 12b as compared with the normal operation. Further, when the food is placed, the quenching 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 rapidly frozen is placed in the thawing zone DZ of the freezing / thawing chamber 12b. As shown in FIG. 12, the signal from the door open / close switch is used as a trigger to weakly operate the oscillation circuit 56 (small oscillation output), and the closing is determined based on the reflectance. After the determination of turning on, 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 rapidly frozen is placed in the thawing zone DZ of the freezing / thawing chamber 12b (timing P6), the reflectance decreases. This is because the food to be rapidly frozen is arranged between the oscillation electrode 52 and the counter electrode 54, so that the dielectric constant between the oscillation electrode 52 and the counter electrode 54 increases.

  In the case of the present embodiment, when the reflectance exceeds the first threshold value R1 and decreases, the control unit 30 determines that the food to be quickly frozen is placed in the defrosting zone DZ of the freezing / thawing chamber 12b. The quenching operation is started instead of the normal operation (timing P7).

  When the rapid cooling operation is started, cooling control is continuously executed as shown in FIG. For example, the compressor 20 and the cooling fan 24 are continuously operated, and the damper 26B is kept open. It should be noted that if there is a surplus power, the output of the compressor 20 and the rotation speed of the cooling fan 24 may be increased as compared with during normal operation.

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

  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 unit 50 applies an AC voltage between the oscillation electrode 52 and the counter electrode 54. Start applying 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, it is possible to freeze the food while suppressing the expansion of ice crystals in the food.

  When the reflectance further decreases and reaches the third threshold value R3, the rate of change of the reflectance decreases. This is because the food temperature reached the temperature just before passing through the maximum ice crystal formation zone. 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 the maximum ice crystal production zone, 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). As a result, the rapid cooling operation ends and the normal operation is resumed.

  The zone thawing operation is an operation of thawing only the foodstuffs arranged in the thawing zone DZ and maintaining the foodstuffs arranged in the non-thawing zone NDZ at the frozen storage temperature Tf. Unlike the rapid cooling operation, the zone defrosting operation is started when the operation unit 32 receives an instruction from the user to switch from the normal operation to the zone defrosting operation. For example, when the user presses the “zone defrost” button on the operation unit 32, the zone defrosting operation is started.

  FIG. 13 is a timing chart of the zone defrosting operation.

  As shown in FIG. 13, when the zone defrosting operation is started, the oscillation circuit 56 of the heating unit 50 starts continuously applying the AC voltage between the oscillation electrode 52 and the counter electrode 54. As a result, the thawing of the food A arranged in the thawing zone DZ starts, and the temperature of the food A begins to rise.

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

  As a result, the food B placed in the non-thawing zone NDZ is frozen and stored as in the normal operation. In this zone defrosting operation, the output of the compressor 20 and the rotation speed of the cooling fan 24 are higher than in the normal operation in consideration of the temperature increase in the freezing / thawing chamber 12b caused by the dielectric heating by the heating unit 50. Also, the opening time of the damper 26B is long.

  Further, according to such a zone thawing operation, the steam generated from the food A being thawed is discharged to the outside of the cooling / thawing chamber 12b by the damper 26B being intermittently opened. Thereby, the relative humidity of the cooling / thawing chamber 12b does not become 100%, and the generation of frost is suppressed.

  When the thawing of the food A arranged in the thawing zone DZ is finished, the zone thawing operation is finished.

  In the case of the present embodiment, the end of thawing the food is judged based on the change in reflectance.

  Looking at FIG. 10 showing the change in reflectance during thawing of food, the reflectance immediately after impedance matching gradually rises as thawing proceeds. For example, the reflectance at the timing P2 is higher than the reflectance at the timing P1. At the timing P5, unlike the timings P1 to P4 before that, the reflectance after impedance matching is a value higher than the third threshold value R3. By appropriately setting the third threshold value R3, when the reflectance lowered by the impedance matching is higher than the third threshold value R3, the execution timing P5 of the impedance matching is regarded as the defrosting end timing. be able to. Therefore, when the reflectance does not drop below the third threshold value due to the impedance matching, the control unit 30 determines that the thawing of the food has finished at the timing of executing the impedance matching, and finishes the zone thawing operation. When the zone defrosting operation is completed, it returns to normal operation. However, depending on the amount and physical properties of the food, the reflectance after matching may exceed R3 even if it is not thawed, or it may not reach R2 even after the thaw is completed. Therefore, the minimum operating time and the maximum operating time may be set regardless of the threshold values R2 and R3.

  The all-zone thawing operation is an operation of thawing not only the food in the freezing / thawing chamber 12b, that is, the food in the thawing zone DZ but also the food in the non-thawing zone NDZ. Similar to the zone defrosting operation, the all-zone defrosting operation is also started by the operation unit 32 receiving an instruction from the user to switch from the normal operation to the all-zone defrosting operation. For example, when the user presses the “decompress all zones” button on the operation unit 32, decompression operation for all zones is started.

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

  As shown in FIG. 14, the all-zone defrosting operation is the same as the zone defrosting 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 that is increased by the dielectric heating of the heating unit 50. However, the damper 26B is momentarily opened to reduce the humidity in the cooling / thawing chamber 12b and suppress the generation of frost, and discharges water vapor to the outside. By such an all-zone thawing operation, all foods in the cooling / thawing chamber 12b are thawed. The all-zone defrosting operation ends as in the zone defrosting operation. After that, it returns to normal operation.

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

  The defrosted food that has been thawed by the zone defrosting operation or the all-zone defrosting operation is left as it is, and then frozen again by the normal operation thereafter. Therefore, the user may take out the thawed food from the freezing / thawing chamber 12b in a re-frozen state. Of course, the refrigerated state is so hard that the user cannot immediately cook the food. To cope with this, it is conceivable to maintain the temperature of the thawed food at a temperature at which it does not freeze after thawing, but in that case, the thawed food may be damaged if left unattended for a long time.

  Therefore, in the case of the present embodiment, when the thawed food is left as it is without being taken out from the cooling / thawing chamber 12b, the thawed food is maintained in a slightly frozen state, that is, the frozen storage temperature (-16 ° C). The micro-freezing operation is performed to maintain the micro-freezing temperature (for example, -3 ° C to -7 ° C) higher than that of (--20 ° C). The term "slightly frozen state" as used herein refers to a state in which the extracellular fluid of a food product does not freeze, but the extracellular fluid of the food product freezes.

  The contents are different between the micro freezing operation (zone micro freezing operation) performed after the zone defrosting operation and the micro freezing operation (all zone micro freezing operation) performed after the all zone defrosting operation.

  After the zone thawing operation, the zone slight freezing operation is executed. This operation is an operation in which the temperature in the freezing / thawing chamber 12b is maintained at the freezing storage temperature and the defrosted food in the thawing zone DZ is heated by the heating unit 50 so that the temperature is maintained at the slight freezing temperature. . As a result, the thawed food in the thaw zone DZ is maintained at the fine freezing temperature, while the food in the non-thaw zone NDZ is maintained at the frozen storage temperature as in the normal operation.

  After the all-zone defrosting operation, the all-zone defrosting operation is executed. This operation is an operation in which the temperature in the freezing / thawing chamber 12b is maintained at a slight freezing temperature while the heating unit 50 is stopped. As a result, the thawed food in the freezing / thawing chamber 12b is maintained at the slight freezing temperature.

  In order to execute the zone and all-zones micro freezing operation, a defrosted food detection unit that detects whether or not the defrosted food is present in the freezing / thawing chamber 12b after the thawing is necessary.

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

  Specifically, as described in the quenching operation, when the food to be frozen is placed in the thawing zone DZ, the reflectance drops below the first threshold value R1. From the opposite point of view, when the thawed food product is taken out of the thaw zone DZ, the reflectance increases above the first threshold value R1. Therefore, if the reflectance rises above the first threshold R1, it can be determined that the defrosted food that has been thawed by the zone thaw operation has been taken out of the thaw zone DZ, or the thaw by the whole zone thaw operation. It can be determined that the processed food has been taken out from the thawing zone DZ and the non-thawing zone NDZ.

  When the presence of the thawed food is detected in the freezing / thaw chamber 12b after the end of the thawing, the zone or all-zone slight freezing operation is executed. Normal operation is performed if the presence of food is not detected.

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

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

  Further details of the zone micro-freezing operation and the all-zone micro-freezing operation will be described with reference to the flowchart shown in FIG.

  As shown in FIG. 15, first, when the zone (all zones) defrosting operation is completed, the control unit 30 starts the zone (all zones) micro freezing operation in step S100.

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

  In step S120, the control unit 30 determines whether or not the food item detected in step S110 is a thawed food item. This is because there is a possibility that the food detected in step S110 is a food that is stored in the freezing / thawing chamber 12b and then frozen. However, when the food detected in step S110 is a food to be frozen, the door of the freezing / thawing chamber 12b is opened by the user after the thawing is completed. That is, the door sensor 34 detects the opening of the door after the thawing is completed. Therefore, when the door sensor 34 does not detect the opening of the door, it is determined that the food item detected in step S110 is a defrosted food item, and the process proceeds to step S130. If not, it is determined that the food detected in step S110 is a food to be frozen, the process proceeds to step S160, the zone (all zones) micro freezing operation is ended, and the quenching operation is started in step S170. .

  When it is determined in step S120 that the food is thawed, in step S130, the control unit 30 determines whether or not a predetermined period has elapsed from the end of thawing. This is because if the thawed food is stored in a slightly frozen state for a long period of time, the quality will deteriorate. In the case of the all-zone defrosting operation, the predetermined period is, for example, 7 days. In the zone defrosting operation, frost is more likely to occur than in the all-zone defrosting operation, so the predetermined period is 5 days, which is shorter than in the all-zone defrosting operation. When the predetermined period has passed from the end of the thawing, the process proceeds to step S140 to end the zone (all zones) micro freezing operation, and then the normal operation is started in step S150. If the predetermined period has not elapsed, the process returns to step S110.

  As described above, according to the present embodiment, it is possible to provide a structure that facilitates the manufacture of a refrigerator capable of thawing food.

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

  For example, in the case of the above-described embodiment, as shown in FIG. 5, both the oscillation circuit 56 and the matching circuit 60 are provided in the heating module 40. However, the present embodiment is not limited to this. At least one of the oscillation circuit 56 and the matching circuit 60 may be provided outside the heating module 40. However, the matching circuit 60 is preferably provided in the vicinity of the oscillation electrode 52 and the counter electrode 54, that is, in the heating module 40 or in the vicinity thereof, in order to achieve impedance matching between the oscillation electrode 52 and the counter electrode 54. Considering heat generation, the oscillator circuit 56 is preferably provided on the back surface of the refrigerator.

  Further, in the case of the above-described 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, the embodiment of the present invention is 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 dielectrically heated and thawed.

  Further, in the case of the above-described embodiment, as shown in FIG. 4, the accommodation chamber of the heating module 40 functions as a freezing / thawing chamber 12b capable of freezing and thawing by introducing cold air. However, the embodiment of the present invention is not limited to this. The heating module may not introduce cold air into its accommodation chamber, i.e. may be dedicated to thawing. The heating module 40 may be used not only for freezing and thawing, but also for cooling and heating food as a temperature control. That is, the accommodation chamber of the heating module 40 may be a cooling / heating chamber.

  Furthermore, in the above-described embodiment, the example of heating and thawing in the freezing chamber has been mainly described, but the heating may be performed in a room in a temperature zone other than that in the refrigerator. For example, by heating milk containing yogurt bacteria or soybean containing natto bacteria stored in a refrigerator, it is possible to promote fermentation to make homemade yogurt or homemade natto.

  It is also possible for a person skilled in the art that at least a part of one embodiment can be combined with another at least one embodiment in whole or in part to form a further embodiment according to the present invention. Is obvious to

  The present invention can be applied to a refrigerator having a thawing function.

10 Refrigerator 12b Storage room (freezing / thawing room)
40 Heating Module 42 Inner Case 44 Shield Case 52 Oscillation Electrode 54 Counter Electrode 56 Oscillator (Oscillation Circuit)
60 Matching part (matching circuit)

Claims (11)

A refrigerator that can heat food,
A shield case made of a material containing metal,
An oscillation electrode provided in the shield case,
A counter electrode arranged to face the oscillation electrode,
A refrigerator in which the counter electrode is integrally formed with the shield case. An inner case that is made of an insulating material, defines a storage chamber in which food is stored, and has an inner case that is stored in the shield case,
The refrigerator according to claim 1, wherein the oscillation electrode is arranged between the inner case and the shield case so as to face the counter electrode of the shield case with the inner case sandwiched therebetween. An oscillating unit for applying an alternating voltage between the oscillating electrode and the counter electrode,
A matching portion for impedance matching between the oscillation electrode and the counter electrode,
The refrigerator according to claim 2, wherein at least one of the oscillation unit and the matching unit is provided in the shield case.   There are a cold air inlet hole that penetrates the shield case and the inner case to introduce cold air into the storage chamber, and a cold air outlet hole that penetrates the shield case and the inner case to discharge the cool air in the storage chamber. The refrigerator according to claim 2 or 3, which is provided.   The refrigerator according to claim 4, wherein the oscillation electrode is provided with a cold air passage hole through which cold air passes.   The refrigerator according to any one of claims 2 to 5, wherein the oscillation electrode and the counter electrode face each other with a part of the storage chamber interposed therebetween. The shield case is
A drawer that is put in and taken out from the storage chamber and stores the food,
The refrigerator according to claim 2, further comprising: a rail that is provided on an inner wall surface of the inner case and that guides the drawer.   The refrigerator according to claim 7, wherein the oscillation electrode and the counter electrode are provided in the inner case so as not to overlap the rail when viewed from the opposite direction of the oscillation electrode and the counter electrode.   The refrigerator according to claim 1, wherein the counter electrode is a raised portion of the shield case that is raised toward the front oscillation electrode. The shield case is provided above the other room,
The access hole which connects the space of the main body of the said refrigerator with which the said shield case is incorporated with the said other room, and which enables access to a heating module from the said other room is provided. The refrigerator according to item 1. An inner case made of an insulating material and defining a storage chamber in which food is stored;
A shield case made of a material containing a metal, integrally provided with a counter electrode, and storing the inner case;
A heating module, comprising: an oscillating electrode arranged between the inner case and the shield case so as to face the counter electrode of the shield case with the inner case sandwiched therebetween.

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