Refrigerator

Abstract

The utility model discloses a refrigerator, which is provided with a storage chamber, a refrigerating chamber and a refrigerating chamber, wherein the storage chamber is provided with a space capable of storing stored objects; an oscillation unit that forms high-frequency electric power; and a first electrode and a second electrode which are disposed facing each other, are connected to the oscillation unit, and receive high-frequency electric power from the oscillation unit to generate an electric field in the storage chamber. In the refrigerator, as the operation mode of the storage chamber, any two or more modes of a freezing mode for freezing the stored object, a storage mode for maintaining the frozen state of the stored object, and a thawing mode for thawing the frozen stored object are provided for the stored object arranged between the first electrode and the second electrode.

Description

Technical Field

[0001] The utility model relates to a cold storage with a freezing function, and the cold storage has a storage room capable of thawing frozen products. Background Art

[0002] In Patent Document 1, a prior art cold storage with a storage room capable of thawing frozen products is disclosed. The cold storage has a cold storage main body, and the cold storage main body has a refrigeration device and a high-frequency generating magnetron. Inside the cold storage main body, a high-frequency heating room (storage room) capable of thawing frozen products together with a freezer is provided. The cold storage main body is configured to supply cold air from the refrigeration device to the high-frequency heating room via a cold air circulation pipe, and irradiate high frequency from the magnetron to thaw the frozen products.

[0003] In Patent Document 2, the following structure is disclosed: at least one of an alternating electric field generating unit that applies an alternating electric field to a frozen object and a magnetic field generating unit that applies a magnetic field is provided in a closed space, and at least one of the alternating electric field and the magnetic field is applied to the frozen object.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2002-147919

[0007] Patent Document 2: Japanese Patent Laid-Open No. 2003-214751 Summary of the Utility Model

[0008] The utility model provides a cold storage, in a storage room capable of thawing frozen products, capable of freezing, storing, and thawing stored items in a desired state, and improving the storage performance of the stored items.

[0009] The cold storage in the utility model includes:

[0010] A storage room having a space capable of storing stored items;

[0011] An oscillation unit that forms high-frequency electric power; and

[0012] A first electrode and a second electrode that are arranged opposite to each other and are each connected to the oscillation unit, and receive high-frequency electric power from the oscillation unit to generate an electric field in the storage room.

[0013] As an operation mode in the storage room, for the stored items arranged between the first electrode and the second electrode, there are any two or more of the following modes:

[0014] A freezing mode for freezing the stored items;

[0015] A storage mode that maintains the deposited object in a frozen state; and

[0016] Thawing mode for thawing frozen stored items. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a longitudinal sectional view of the refrigerator according to the first embodiment.

[0018] Figure 2 This is a front cross-sectional view showing the freezer / thaw compartment of the refrigerator according to the first embodiment.

[0019] Figure 3 This is a side cross-sectional view showing the freezer / thaw compartment of the refrigerator according to the first embodiment.

[0020] Figure 4 This is a longitudinal sectional view of the freezer / thaw compartment in the refrigerator according to the first embodiment when assembled.

[0021] Figure 5 This is a front cross-sectional view showing a modified example of the freezer / thaw compartment in the refrigerator according to the first embodiment.

[0022] Figure 6 This is a side cross-sectional view showing a modified example of the freezer / thaw compartment in the refrigerator according to the first embodiment.

[0023] Figure 7 This is a longitudinal sectional view of the freezer / thaw compartment in the refrigerator according to the first embodiment when assembled.

[0024] Figure 8 This is a diagram showing the electrode holding area on the back side of the freezer / thaw compartment according to the first embodiment.

[0025] Figure 9 This is a block diagram showing the configuration of a dielectric heating mechanism provided in the refrigerator according to the first embodiment.

[0026] Figure 10 This is a schematic circuit diagram of an AC / DC converter that drives various circuits.

[0027] Figure 11 This is a plan view of the first electrode and the second electrode on the top surface side of the freezer / thaw compartment in the refrigerator according to the first embodiment, as viewed from above.

[0028] Figure 12 This is a diagram showing the relationship between the electrode distance between the first electrode and the second electrode and the electric field intensity between the two electrodes.

[0029] Figure 13A Graphs showing the results of electric field simulations of a dielectric heating structure in a comparative example.

[0030] Figure 13BIt is a diagram showing the result of an electric field simulation of the dielectric heating structure of the freezing / thawing chamber in the refrigerator of Embodiment 1.

[0031] Figure 14 It is a diagram showing the waveforms of the control signals of the oscillation circuit and the air damper during the electric field generation process in the structure of Embodiment 1, and showing the food temperature, the chamber temperature of the freezing / thawing chamber, and the humidity of the freezing / thawing chamber at this time.

[0032] Figure 15 It is a flowchart showing the control after the electric field generation process is completed in the freezing / thawing chamber in the structure of Embodiment 1.

[0033] Figure 16A It is a waveform diagram showing the cooling operation during frozen storage in a conventional refrigerator.

[0034] Figure 16B It is a waveform diagram showing the cooling operation performed in the freezing / thawing chamber in the refrigerator of Embodiment 1.

[0035] Figure 17 It is a waveform diagram showing the states of the respective elements during the rapid cooling operation in the structure of Embodiment 1.

[0036] Figure 18A It is a diagram showing an example of a high-frequency cut-off circuit when the door of the refrigerator of Embodiment 1 is opened.

[0037] Figure 18B It is a diagram showing another example of the high-frequency cut-off circuit when the door of the refrigerator of Embodiment 1 is opened.

[0038] Figure 18C It is a diagram showing yet another example of the high-frequency cut-off circuit when the door of the refrigerator of Embodiment 1 is opened.

[0039] Figure 19A It is a cross-sectional view showing an example of the cable wiring to the freezing / thawing chamber in the refrigerator of Embodiment 1.

[0040] Figure 19B It is a cross-sectional view showing an example of the cable wiring to the freezing / thawing chamber in the refrigerator of Embodiment 1. Detailed Embodiments

[0041] (Insights etc. that form the basis of the present disclosure)

[0042] When the inventors conceived of the present utility model, a refrigerator described in Patent Document 1 was known.

[0043] The cold storage is configured to irradiate frozen products in a high-frequency heating chamber with high-frequency waves from a magnetron via an antenna or the like for high-frequency heating. Therefore, it is difficult to uniformly heat and thaw the frozen products into a desired state. In addition, it is a structure in which high-frequency waves are irradiated from the magnetron to the frozen products for high-frequency heating. Therefore, a relatively large magnetron and its cooling mechanism need to be provided as components, and there is a problem that miniaturization is difficult to achieve.

[0044] In addition, when freezing a stored item, it has been studied to suppress the generation of ice crystals by applying an alternating electric field to the stored item. For example, Patent Document 2 describes a refrigeration device that applies an alternating electric field to an object to be frozen. However, in the refrigeration device described in Patent Document 2, it is difficult to melt the ice crystals generated in the stored item, and there is a problem that the cell membrane of the stored item is damaged when freezing.

[0045] In addition, due to the differences in output frequency and output power, the high-frequency generation systems of the cold storage described in Patent Document 1 and the freezer described in Patent Document 2 are difficult to be applied simultaneously in one device. As shown in Patent Document 2, if a device using metal components is used in a freezer environment, dew condensation and frosting will occur due to moisture invading from food and the outside. And there is a problem of malfunction due to dew condensation and frosting.

[0046] In view of such problems, the inventor has constituted the subject matter of the present utility model in order to solve these problems.

[0047] The present utility model provides a cold storage that can freeze, store, and thaw stored items in a storage chamber in a desired state. In addition, miniaturization of the device is achieved simultaneously.

[0048] Hereinafter, as an embodiment of the cold storage of the present utility model, a cold storage having a freezing function will be described with reference to the drawings. In addition, the cold storage of the present utility model is not limited to the structure of the cold storage described in the following embodiments, and can also be applied to a freezer having only a freezing function, including various cold storages and freezers having the technical features described in the following embodiments. Therefore, in the present utility model, the cold storage is a structure having at least one of a refrigerating chamber and a freezing chamber.

[0049] In addition, the numerical values, shapes, structures, steps, and order of steps shown in the following embodiments represent an example and do not limit the present utility model. Regarding the components in the following embodiments that are not described in the independent claims representing the most general concept, they are described as optional components. In addition, in the embodiments, the same reference numerals are given to the same elements in the modification examples, and the description may sometimes be omitted. In addition, for easy understanding, the drawings schematically show each component as the main body.

[0050] (Embodiment 1)

[0051] Hereinafter, the refrigerator of Embodiment 1 of the present utility model will be described with reference to the accompanying drawings. In addition, in the description of the present utility model, for easy understanding, the description will be divided according to each item.

[0052] [1-1. Overall Structure of Refrigerator]

[0053] Figure 1 It is a diagram showing a longitudinal section of the refrigerator 1 of Embodiment 1.

[0054] In Figure 1 , the left side is the front side of the refrigerator 1, and the right side is the back side of the refrigerator 1. The refrigerator 1 mainly consists of the following components: an outer box 3 mainly formed of steel plates; an inner box 4 formed of a resin such as ABS (acrylonitrile-butadiene-styrene) resin; and a heat insulation box 2 formed by filling the space between the outer box 3 and the inner box 4 with foamed heat insulation material 40 (for example, rigid foamed polyurethane).

[0055] The heat insulation box 2 of the refrigerator 1 has a plurality of storage rooms, and doors that can be opened and closed are arranged at the front side openings of each storage room. Each storage room is sealed by closing the door to prevent cold air from leaking. In the refrigerator 1 of Embodiment 1, the uppermost storage room is the refrigerating chamber 5. Two storage rooms, the ice making chamber 7 and the freezing / thawing chamber 6, are arranged in parallel on both sides directly below the refrigerating chamber 5. The freezing chamber 8 is arranged directly below the ice making chamber 7 and the freezing / thawing chamber 6. The vegetable chamber 9 is arranged at the lowermost part, that is, directly below the freezing chamber 8. Each storage room in the refrigerator 1 of Embodiment 1 has the above structure, but this structure is an example, and the arrangement structure of each storage room can be appropriately changed during design according to specifications and the like.

[0056] The refrigerating chamber 5 is maintained at a non-freezing temperature for refrigerating and storing food and other stored items. As a specific temperature example, it is maintained in the temperature range of 1°C to 5°C. The vegetable chamber 9 is maintained in a temperature range equal to or slightly higher than that of the refrigerating chamber 5, for example, 2°C to 7°C. The freezing chamber 8 is set to a freezing temperature range for freezing storage. As a specific temperature example, for example, it is set to -22°C to -15°C. The freezing / thawing chamber 6 is usually maintained in the same freezing temperature range as the freezing chamber 8, and according to the user's thawing instruction, a thawing process for thawing the stored items (frozen products) stored therein is performed. The details of the structure and thawing process of the freezing / thawing chamber 6 will be described later. In addition, in the present utility model, the thawing instruction is equivalent to one of the electric field generation instructions in the device. Therefore, hereinafter, the thawing instruction will sometimes be described as an electric field generation instruction.

[0057] A machinery room 10 is provided above the cold storage 1. Components constituting a refrigeration cycle such as a compressor 19 and a dryer for removing moisture in the refrigeration cycle are housed in the machinery room 10. In addition, as the installation position of the machinery room 10, it is not limited to the upper part of the cold storage 1, but is appropriately determined according to the installation position of the refrigeration cycle, etc., and can also be installed in other areas such as the lower part of the cold storage 1.

[0058] A cooling chamber 11 is provided on the back side of the freezer 8 and the vegetable chamber 9 in the lower area of the cold storage 1. In the cooling chamber 11, a cooler 13 as a component of the refrigeration cycle for generating cold air and a cooling fan 14 for sending the cold air generated by the cooler 13 to each storage chamber (the refrigerating chamber 5, the freezing / thawing chamber 6, the ice-making chamber 7, the freezer 8, and the vegetable chamber 9) are provided. The cold air generated by the cooler 13 flows through the air duct 12 connected to each storage chamber by the cooling fan 14 and is supplied to each storage chamber. An air damper 12a is provided in the air duct 12 connected to each storage chamber. By controlling the rotational speeds of the compressor 19 and the cooling fan 14 and the opening and closing of the air damper 12a, each storage chamber is maintained in a specified temperature range. A defrost heater 15 for defrosting the frost or ice adhering to the cooler 13 and its periphery is provided below the cooling chamber 11. A drain pan 16, a drain pipe 17, and an evaporation pan 18 are provided below the defrost heater 15. With these structures, it is possible to evaporate the moisture generated during defrosting and the like.

[0059] In the cold storage 1 of the first embodiment, there is an operation unit 47 (refer to Figure 9 described later). The user can perform various instructions for the cold storage 1 (for example, temperature setting of each storage chamber, rapid cooling instruction, thawing instruction, or ice-making stop instruction, etc.) on the operation unit 47. In addition, the operation unit 47 has a display unit for notifying the occurrence of an abnormality and the like. In addition, in the cold storage 1, it can also be configured to be connected to a wireless LAN network by having a wireless communication unit, so as to input various instructions from the user's external terminal. In addition, in the cold storage 1, it can also be configured to have a voice recognition unit for the user to input voice-based instructions.

[0060] Figure 2 is a front cross-sectional view of the freezing / thawing chamber 6 of the cold storage 1 of the first embodiment. Figure 3 、 Figure 4 、 Figure 6 and Figure 7 are longitudinal cross-sectional views of the freezing / thawing chamber 6 in the cold storage 1 of the first embodiment. The freezing / thawing chamber 6 is a freezer that keeps stored items such as food stored therein in a freezing temperature range. In addition, when a thawing instruction (electric field generation instruction) for the stored item is input to the cold storage 1 in the freezing / thawing chamber 6, it becomes a thawing chamber for performing thawing processing (electric field generation processing) by dielectric heating.

[0061] Regarding Figure 3 、 Figure 4 、 Figure 6 and Figure 7 their respective details will be re - described in "1 - 4. Structure of the Dielectric Heating Mechanism System" described later.

[0062] In the freezing / thawing chamber 6, the cold air generated in the cooler 13 flows in the air ducts 12 provided on the back side and the top side of the freezing / thawing chamber 6, and is introduced into the interior of the freezing / thawing chamber 6 through a plurality of cold air introduction holes 20 provided on the top surface of the freezing / thawing chamber 6 to maintain the same freezing temperature range as that of the freezing chamber 8. An air damper 12a is provided in the air duct 12 leading from the cooling chamber 11 to the freezing / thawing chamber 6. By controlling the opening and closing of the air damper 12a, the freezing / thawing chamber 6 is maintained in a specified freezing temperature range, and the stored items stored therein are frozen and stored.

[0063] A cold air discharge hole (not shown) is formed on the back surface of the freezing / thawing chamber 6. The cold air introduced into the freezing / thawing chamber 6 and used to cool the interior of the freezing / thawing chamber 6 returns to the cooling chamber 11 through a return air duct (not shown) from the cold air discharge hole and is recooled by the cooler 13. That is, the refrigerator 1 of the first embodiment is configured to circulate the cold air formed by the cooler 13.

[0064] The top surface, back surface, both side surfaces, and bottom surface of the inner surface that constitutes the storage space in the freezing / thawing chamber 6 are formed by an inner surface member 32 (32a to 32c) of a resin material, and the inner surface member 32 (32a to 32c) is formed of an electrically insulating material. In addition, a door 29 is provided to open on the front side of the freezing / thawing chamber 6, and the storage space of the freezing / thawing chamber 6 is sealed by closing the door 29. In the freezing / thawing chamber 6 of the first embodiment, a storage box 31 with an open top is provided on the back side of the door 29. And it is configured such that when the door 29 is opened and closed in the front - rear direction, the storage box 31 moves forward and backward simultaneously. By making the opening and closing movement of the door 29 in the front - rear direction, it is easy to put in and take out stored items such as food with respect to the storage box 31.

[0065] [1 - 2. Dielectric Heating Mechanism]

[0066] Next, a dielectric heating mechanism for generating an electric field in the storage space of the freezing / thawing chamber 6 will be described. Through dielectric heating based on the dielectric heating mechanism, thawing treatment of stored items arranged in the storage space is performed, for example.

[0067] In addition, the dielectric heating mechanism of the present embodiment can adjust heating capabilities such as output power. Therefore, when the heating amount of the stored item exceeds the cooling amount of the freezing / thawing chamber 6, the stored item is heated. In addition, when the heating amount of the stored item is lower than the cooling amount of the freezing / thawing chamber 6, the stored item is cooled.

[0068] Figure 9 FIG. is a block diagram showing the structure of the dielectric heating mechanism provided in the refrigerator 1 of Embodiment 1. The dielectric heating mechanism in Embodiment 1 includes an oscillation circuit 22, a matching circuit 23, a first electrode 24, a second electrode 25, and a control unit 50. The oscillation circuit 22 is supplied with power from a power supply unit 48 to form a prescribed high-frequency signal. The oscillation circuit 22 is composed of semiconductor elements and is miniaturized. As will be described later, the oscillation circuit 22 and the matching circuit 23 are formed together on an electrode holding substrate 52 in a space on the back side of the freezing / thawing chamber 6, i.e., an electrode holding region 30 (refer to Figure 3 , Figure 4 , Figure 6 and Figure 7 ). The oscillation circuit 22 and the matching circuit 23 serve as a high-frequency electric power forming unit for forming a high-frequency electric field applied between the electrodes of the first electrode 24 and the second electrode 25.

[0069] The first electrode 24 is an electrode disposed on the top surface side of the freezing / thawing chamber 6. The second electrode 25 is an electrode disposed on the bottom surface side of the freezing / thawing chamber 6. The first electrode 24 and the second electrode 25 are disposed opposite to each other across the storage space (thawing space) of the freezing / thawing chamber 6. An electrode holding substrate 52 and the like described in "1-3. Structure of the Circuit Substrate of the Dielectric Heating Mechanism" to be described later are provided, and the relative interval between the first electrode 24 and the second electrode 25 is set to a prescribed interval ( Figure 8 's H) set in advance. As a result, in the dielectric heating mechanism of Embodiment 1, the first electrode 24 and the second electrode 25 are disposed substantially in parallel. In addition, in the present invention, "substantially in parallel" means a state that is essentially parallel, but includes errors caused by deviations such as machining accuracy.

[0070] The first electrode 24 is provided on one surface of the storage space. The second electrode 25 is provided on the other surface of the storage space opposite to the one surface across the storage space. The matching circuit 23 on the back side, the first electrode 24 on the top surface side, and the second electrode 25 on the bottom surface side that constitute the dielectric heating mechanism are covered by an inner surface member 32. Thereby, it is possible to reliably prevent burns of the stored item (Joule heating of food ingredients) caused by contact between the stored item and the matching circuit 23, the first electrode 24, or the second electrode 25.

[0071] In addition, in the structure of Embodiment 1, a structure will be described in which a first electrode 24 is provided on the top surface portion of the storage space constituting the freezing / thawing chamber 6, and a second electrode 25 is provided on the bottom surface portion of the storage space of the freezing / thawing chamber 6. However, the present utility model is not limited to this configuration. As long as the first electrode 24 and the second electrode 25 face each other across the storage space (thawing space), even if the first electrode 24 and the second electrode 25 are arranged upside down compared to this embodiment, or the first electrode 24 and the second electrode 25 face each other in the left-right direction across the storage space, the same effect can be achieved.

[0072] The oscillation circuit 22 outputs a high-frequency voltage in the VHF (Very High Frequency) band (40.68 MHz in Embodiment 1). By outputting the high-frequency voltage from the oscillation circuit 22, an electric field is formed between the first electrode 24 and the second electrode 25 connected to the oscillation circuit 22. As a result, the storage item serving as a dielectric in the storage space between the first electrode 24 and the second electrode 25 disposed in the freezing / thawing chamber 6 is dielectrically heated, for example, thawed.

[0073] The matching circuit 23 adjusts so that the load impedance formed by the first electrode 24, the second electrode 25, and the storage item stored in the freezing / thawing chamber 6 matches the output impedance of the oscillation circuit 22. By making the impedance match in the matching circuit 23, the reflected wave for the output high-frequency is minimized.

[0074] In the dielectric heating mechanism in Embodiment 1, an incident / reflected wave detection unit 51 is provided that detects the incident wave output from the oscillation circuit 22 to the first electrode 24 and the reflected wave returning from the first electrode 24 to the oscillation circuit 22 side. The oscillation circuit 22 is electrically connected to the first electrode 24 via the incident / reflected wave detection unit 51 and the matching circuit 23. The control unit 50 calculates the ratio (reflectivity) of the reflected wave output to the incident wave output based on the incident wave and the reflected wave detected by the incident / reflected wave detection unit 51, and performs various controls as described later based on the calculation result. In addition, the ratio (reflectivity) of the reflected wave output to the electromagnetic wave output may be calculated based on the set value of the high-frequency electric power output from the oscillation circuit 22 during impedance matching in the matching circuit 23 and the reflected wave detected by the incident / reflected wave detection unit 51. In addition, the following various controls may be performed using only the reflected wave output regardless of the output set value of the electromagnetic wave or the detected value of the incident wave.

[0075] As Figure 9As shown in the control block diagram, in the dielectric heating mechanism, the control unit 50 drives and controls the oscillation circuit 22 and the matching circuit 23 based on signals from the operation unit 47 where the user performs setting operations and temperature sensors 49 that detect the temperature inside the storage. The control unit 50 is composed of a CPU (Central Processing Unit) and performs various controls by executing control programs stored in memories such as ROM (Read Only Memory).

[0076] [1-3. Structure of the circuit board of the dielectric heating mechanism]

[0077] To improve reliability, the lengths of the wirings connecting the oscillation circuit 22, the incident reflection wave detection unit 51, the matching circuit 23, and the positive electrode side of the first electrode 24 are preferably short. Therefore, in the present embodiment, the electrode holding substrate 52 (refer to Figure 3 , Figure 4 , Figure 6 and Figure 7 ) including these circuits is directly connected to the first electrode 24, and the electrode holding substrate 52 is directly connected to the second electrode 25 without going through leads or coaxial cables, etc. In addition, the electrode holding substrate 52 is disposed in the electrode holding region 30 on the back side of the freezing / thawing chamber 6. Furthermore, this electrode holding substrate 52 includes at least the matching circuit 23.

[0078] The matching circuit 23 performs impedance matching by adjusting the values of inductance and capacitance. Therefore, the matching circuit 23 generates heat especially due to the loss of the inductor on the matching circuit 23. This heat generation is expressed as waste heat generated by the matching circuit 23. Devices including the matching circuit 23, the first electrode 24 and the second electrode 25 disposed around the matching circuit 23, and the electromagnetic wave shielding members 26 (26a to 26d) described later, etc., are prone to condensation in a freezing temperature environment. Due to condensation, water droplets and frost are generated on the high-frequency electric power transmission path or these devices located on the transmission path, which may cause malfunction of the devices. However, by adopting a structure in which the waste heat generated by the matching circuit 23 is easily conducted to these devices, malfunction can be prevented. Therefore, it is preferable that the electrode holding substrate 52 includes at least the matching circuit 23.

[0079] In addition, the first electrode 24, the second electrode 25, and the electromagnetic wave shielding member 26 described later generate heat due to certain electrical losses. In Embodiment 1, the heat generation in the first electrode 24, the second electrode 25, and the electromagnetic wave shielding member 26 is very small and hardly contributes to preventing condensation and frosting. However, as the first electrode 24, the second electrode 25, and the electromagnetic wave shielding member 26, it is also possible to prevent condensation and frosting by deliberately and appropriately using materials with large losses.

[0080] The dew condensation or frost formation prevention operation using waste heat has nothing to do with the necessity of generating an electric field in the freezing / thawing chamber 6, and is implemented when the possibility of dew condensation or frost formation is detected. That is, when the possibility of dew condensation or frost formation is detected, the oscillation circuit 22 is made to operate moderately, and an operation of generating waste heat is intentionally performed.

[0081] In order to accurately determine whether impedance matching can be sufficiently performed through the matching circuit 23, an incident reflection wave detection unit 51 is formed on the electrode holding substrate 52. Preferably, the incident reflection wave detection unit 51 and the matching circuit 23 are combined into one substrate. Thus, it is not necessary to arrange leads, coaxial cables, and connector types for connecting the leads or coaxial cables between the matching circuit 23 and the incident reflection wave detection unit 51. Therefore, the structure of the circuit board can also be simplified.

[0082] In Figure 9 the incident reflection wave detection unit 51 and the matching circuit 23 are arranged on the electrode holding substrate 52. However, the matching circuit 23, the incident reflection wave detection unit 51, and the oscillation circuit 22 may also all be formed on one substrate. Thus, power transmission loss generated by leads or coaxial cables can be suppressed, and the accuracy of impedance matching can also be improved.

[0083] In addition, each of the above circuits, such as the oscillation circuit 22 and the matching circuit 23, may also be formed separately and electrically connected through leads or coaxial cables, etc. In such a case, for example, by using the machinery room 10 having a relatively large free space to arrange the oscillation circuit 22, etc., a reasonable configuration structure for effectively utilizing the free space in the refrigerator can also be realized. In addition, in this case, in order to perform impedance matching including coaxial cables, it is preferable to arrange the oscillation circuit 22 and the incident reflection wave detection unit 51 on one substrate.

[0084] [1-4. System Structure of Dielectric Heating Mechanism]

[0085] In the dielectric heating mechanism of Embodiment 1 configured as described above, the first electrode 24 and the second electrode 25 are arranged to face each other substantially in parallel. Therefore, the homogenization of the electric field is achieved in the thawing space, which is the storage space of the freezing / thawing chamber 6. In order to arrange the first electrode 24 and the second electrode 25 substantially in parallel with a predetermined interval ( Figure 8 of H), in the dielectric heating mechanism of Embodiment 1, the electrode interval is maintained as described below.

[0086] Figure 8 It is a diagram showing the electrode holding region 30 on the back side of the freezing / thawing chamber 6 in Embodiment 1, and showing the electrode holding mechanism in the electrode holding region 30. Figure 8FIG. 0 is a view of the electrode holding region 30 as viewed from the back side. A first electrode 24 is disposed on the upper side (top side), and a second electrode 25 is disposed on the lower side (bottom side). Positive terminals 24a, 24b, and 24c are protrudingly provided at the back side end of the first electrode 24. The positive terminals 24a to 24c are protrudingly provided so as to be bent at a right angle upward (top side) or downward (bottom side) from the back side end of the first electrode 24. Similarly, negative terminals 25a, 25b, and 25c are protrudingly provided at the center of the back side end of the second electrode 25. The negative terminals 25a to 25c are protrudingly provided so as to be bent at a right angle upward (top side) or downward (bottom side) from the back side end of the second electrode 25.

[0087] The first electrode 24 and the second electrode 25 are respectively fixed to the upper part and the lower part of the electrode holding substrate 52. A matching circuit 23 and an incident reflected wave detection unit 51 are fixed to the electrode holding substrate 52. The first electrode 24 and the second electrode 25 are reliably held by the electrode holding substrate 52. In this way, the electrode holding substrate 52 substantially holds the first electrode 24 and the second electrode 25 in a manner having a specified distance ( Figure 8 H). In addition, since the electrode holding substrate 52 constitutes the matching circuit 23 and the like, its rigidity is increased by the copper foil wiring pattern. Therefore, the electrode holding substrate 52 can hold the first electrode 24 and the second electrode 25 in a cantilever manner respectively in a state where there is a specified relative interval ( Figure 8 H) between the first electrode 24 and the second electrode 25. In addition, as described above, an oscillation circuit 22 and the like can also be provided on the electrode holding substrate 52.

[0088] The positive terminals 24a to 24c of the first electrode 24 and the negative terminals 25a to 25c of the second electrode 25 are respectively connected to the specified connection terminals on the positive electrode side and the negative electrode side of the matching circuit 23. The connection between each of the positive terminals 24a to 24c and the negative terminals 25a to 25c and the corresponding connection terminals of the matching circuit 23 is a surface contact connection having a specified contact area, so that reliability can be ensured even when a large current flows. In Embodiment 1, in order to ensure a reliable surface contact connection, the flat terminals are connected to each other by screw fixation. In addition, as the connection between the terminals, any connection method that can achieve a reliable surface contact connection can be used, and it is not limited to the screw fixation connection. In addition, in order to implement the above-described dew condensation or frost formation prevention operation using waste heat, a connection between terminals having excellent thermal conductivity is also preferred.

[0089] As described above, an electrode holding substrate 52 is provided on the back side of the freezing / thawing chamber 6 as an electrode holding mechanism. Therefore, a structure is formed in which the first electrode 24 and the second electrode 25 face each other substantially in parallel. In addition, in the first embodiment, in order to more reliably make the first electrode 24 and the second electrode 25 face each other substantially in parallel, they are configured as a high-frequency heating module 53a. The high-frequency heating module 53a includes the first electrode 24, the second electrode 25, and the electrode holding substrate 52, and is integrated in a state where the first electrode 24 and the second electrode 25 are determined to be in a substantially parallel state, and is assembled to the freezing / thawing chamber 6.

[0090] [1-5. Structure of Freezing / Thawing Chamber]

[0091] As described above, the heat-insulating box body 2 of the refrigerator 1 includes: an outer box 3 formed of a steel plate; an inner box 4 formed of resin molding; and a heat-insulating material 40 (e.g., rigid foamed polyurethane) filled in a space between the outer box 3 and the inner box 4 in a foamed state.

[0092] And, as Figure 2 and Figure 3 shown, the freezing / thawing chamber 6 is configured with the inner surface member 32a on the inner surface of the heat-insulating material 40 as an outer frame. The outside of the freezing / thawing chamber 6 is covered with an electromagnetic wave shielding member 26 (26a to 26d). In order to prevent electromagnetic waves from leaking to the outside of the refrigerator 1, the electromagnetic wave shielding member 26 is provided so as to surround the freezing / thawing chamber 6. In addition, the electrode holding region 30 is partitioned from the freezing / thawing chamber 6 by the inner surface member 32a. A back side electromagnetic wave shielding member 26b is provided on the back side of the inner surface member 32a. The main purpose of the back side electromagnetic wave shielding member 26b is to prevent the influence on the impedance and electric field of each other by partitioning the inside of the freezing / thawing chamber 6 and the electrode holding substrate 52 including the matching circuit 23 and the like.

[0093] A flat inner surface member 32b is provided horizontally in the upper part of the space surrounded by the inner surface member 32a, and the first electrode 24 is loaded on the upper side of the inner surface member 32b. In addition, a flat inner surface member 32c is provided horizontally in the lower part of the space surrounded by the inner surface member 32a, and the second electrode 25 is provided on the lower surface of the inner surface member 32c. The lower surface of the inner surface member 32c is substantially parallel to the inner surface member 32b and is maintained at a predetermined distance ( Figure 8 of H). Therefore, the first electrode's 24 and the second electrode 25 are held in a substantially parallel state by the electrode holding substrate 52 and the inner surface members 32a, 32b, and 32c. Due to uneven foaming of the foamed heat-insulating material 40 filled in the outer box 3, the parallelism between the upper surface and the bottom surface inside the chamber may sometimes become insufficient. However, with the above-described structure, it is not affected by foaming, and the first electrode 24 and the second electrode 25 can be made to be in a substantially parallel state with high precision and reliability.

[0094] The high-frequency heating module 53a is pre-assembled. In the manufacturing process of the refrigerator 1, as Figure 4 shown, the high-frequency heating module 53a is assembled in a form inserted into the outer box 3 of the refrigerator 1. And the refrigerator is completed in a form of inserting a door assembly including a door 29, a door-side electromagnetic wave shielding member 26d, a gasket 36, a storage box 31, etc. into the high-frequency heating module 53a.

[0095] In addition, it may also be Figure 5 , Figure 6 and Figure 7 the structure shown. In Figure 5 , Figure 6 and Figure 7 , regarding the outer box 3 of the refrigerator 1, the inner box 4 formed of resin, the space between the outer box 3 and the inner box 4 filled with foamed heat insulating material 40, the inner surface member 32 (32a to 32c) on the inner surface of the heat insulating material 40 which forms the outer frame of the freezing / thawing chamber 6, and the electromagnetic wave shielding member 26 on the outer side of the inner surface member 32, the structure is the same as Figure 2 and Figure 3 .

[0096] A flat plate-shaped inner surface member 32b provided in the horizontal direction is provided at the upper part of the space surrounded by the inner surface member 32a. The first electrode 24 is loaded on the upper side of the inner surface member 32b. In addition, a flat plate-shaped inner surface member 32c provided in the horizontal direction is similarly arranged at the lower part of the space surrounded by the inner surface member 32a. The second electrode 25 is provided on the lower surface of the inner surface member 32c. The front sides of the inner surface member 32b and the inner surface member 32c are respectively fixed by the support columns 54. The back sides of the inner surface member 32b and the inner surface member 32c are fixed by the electrode holding substrate 52 and the inner surface member 32a, and the first electrode 24 and the second electrode 25 are held in a substantially parallel state.

[0097] The inner surface member 32b and the inner surface member 32c are substantially parallel and maintained at a specified distance ( Figure 8 H), so for the first electrode 24 and the second electrode 25, they can be held in a substantially parallel state by the electrode holding substrate 52, the support columns 54, and the inner surface members 32b, 32c. Due to the uneven foaming of the foamed heat insulating material 40 filled in the outer box 3 of the refrigerator 1, sometimes the parallelism between the upper surface and the bottom surface inside the refrigerator becomes insufficient. However, through the above structure, it is not affected by the foaming, and the first electrode 24 and the second electrode 25 can be made to be in a substantially parallel state with high precision and reliability.

[0098] In the above structure, as the high-frequency heating module 53a, the first electrode 24, the second electrode 25, the inner surface members 32a, 32b, 32c, the support columns 54, the partition electrode holding region 30, the electromagnetic wave shield 26b on the back side of the freezing / thawing chamber 6, and the electrode holding substrate 52 including the matching circuit 23 etc. are integrated. The high-frequency heating module 53a is pre-assembled and, as Figure 4 shown, in the manufacturing process, it is assembled in the form of inserting the high-frequency heating module 53a into the outer box 3 of the refrigerator 1. And, the door assembly including the door 29, the door-side electromagnetic wave shield 26d, the gasket 36, the storage box 31 etc. is inserted into the high-frequency heating module 53a to complete the refrigerator 1.

[0099] In addition, the inner surface members 32a to 32c are preferably materials with a thermal conductivity of 10 W / (m·k) or less of a general industrial ceramic material that is difficult to dew even in the environment of the freezing chamber. In the present embodiment, the inner surface members 32a to 32c are made of resin materials such as polypropylene, ABS resin, and polycarbonate. The electromagnetic wave shield 26 (26a to 26d) is configured to have a thickness thinner than that of the inner surface member 32 (32a to 32c), and the heat capacity is suppressed. Thereby, it is possible to prevent dew condensation on the electromagnetic wave shield 26 and the inner surface member 32 (32a to 32c) in contact with the electromagnetic wave shield 26.

[0100] Thus, in the refrigerator 1 of Embodiment 1, an electrode holding mechanism is provided on the back side, front side, or side side of the dielectric heating mechanism of the freezing / thawing chamber 6. Therefore, the first electrode 24 and the second electrode 25 can be disposed with a high-precision relative interval to each other. Therefore, the first electrode 24 and the second electrode 25 can be disposed reliably substantially in parallel with a prescribed interval ( Figure 8 H). As a result, the dielectric heating mechanism of the freezing / thawing chamber 6 can prevent deviation of the high-frequency electric field on the electrode surface and achieve uniformization of the high-frequency electric field, and thus can uniformly perform the thawing process on the stored items (frozen products).

[0101] In addition, since the refrigerator is completed by inserting a pre-assembled component as the high-frequency heating module, there is no need to perform manufacturing operations inside the narrow refrigerator compartment, and the manufacturing process becomes simple.

[0102] [1-6. Electromagnetic Wave Shielding Mechanism]

[0103] As described above, in the freezing / thawing chamber 6, a dielectric as a stored item is disposed in the atmosphere of the high-frequency electric field between the first electrode 24 and the second electrode 25 and dielectric heating is performed. Therefore, electromagnetic waves are radiated in the freezing / thawing chamber 6. In order to prevent the leakage of these electromagnetic waves to the outside of the refrigerator 1, an electromagnetic wave shielding mechanism is provided to surround the freezing / thawing chamber 6 in the refrigerator 1 of Embodiment 1.

[0104] As Figure 2 and Figure 3 shown, on the air passage 12 part on the top surface side of the freezing / thawing chamber 6, a top surface side electromagnetic wave shield 26a is disposed. The top surface side electromagnetic wave shield 26a is disposed on the lower surface of the heat insulating material 40 on the bottom surface side of the refrigerating chamber 5 (refer to Figure 1 ) that constitutes directly above the freezing / thawing chamber 6, and is disposed so as to cover the top surface side of the freezing / thawing chamber 6. The top surface side electromagnetic wave shield 26a has a plurality of openings and is configured such that the substantial relative area with respect to the first electrode 24 becomes smaller.

[0105] In the present embodiment, the shape of the opening is a slit shape with the long side direction from the back surface side to the front surface side. Through electromagnetic wave simulation analysis, it is found that: through the openings of the top surface side electromagnetic wave shield 26a, the magnetic field (current) generated from the positive terminal 24a to 24c directions towards the front smoothly passes through the top surface side electromagnetic wave shield 26a, so that the leakage magnetic field diffusing to the surroundings can be suppressed.

[0106] By the top surface side electromagnetic wave shield 26a configured in this way, the generation of an unnecessary electric field between the top surface side electromagnetic wave shield 26a and the first electrode 24 can be suppressed. In addition, the top surface side electromagnetic wave shield 26a may also be a mesh structure having a plurality of openings. In addition, the top surface side electromagnetic wave shield 26a may also be provided inside the refrigerating chamber 5 located directly above the freezing / thawing chamber 6. In the refrigerating chamber 5, a semi-frozen chamber or an ice-temperature fresh-keeping chamber is mostly provided, and the top surface of the semi-frozen chamber or the ice-temperature fresh-keeping chamber may also be used as an electromagnetic wave shield.

[0107] A back surface side electromagnetic wave shield 26b is disposed so as to cover the electrode holding region 30 provided on the back surface side of the freezing / thawing chamber 6. A matching circuit 23 etc. are disposed in the electrode holding region 30. By providing the back surface side electromagnetic wave shield 26b in this way, the influence on the operation (control) of the electrical installation components such as the cooling fan 14 and the air damper 12a caused by the electric field generated between the first electrode 24 and the second electrode 25 and the high-frequency noise etc. generated from the matching circuit 23 is prevented. In addition, an electromagnetic wave shield (not shown) is also disposed on the side surface side of the freezing / thawing chamber 6.

[0108] Next, the door-side electromagnetic wave shield 26d of the door 29 provided at the front-side opening of the opening / closing refrigerating / freezing chamber 6 will be described. The door 29 is configured to open and close with respect to the main body of the refrigerator 1. Therefore, in the case of forming a structure in which the electromagnetic wave shield provided on the door 29 is connected to the grounding portion of the main body of the refrigerator 1 through a wired circuit, as the door 29 opens and closes, the wired circuit repeatedly expands and contracts, and metal fatigue accumulates in the wired circuit. In a structure connected in this way, there is a possibility of disconnection in the wired circuit. Therefore, a structure in which the door-side electromagnetic wave shield 26d provided on the door 29 is connected to the grounding portion of the main body of the refrigerator 1 through a wired circuit is not preferred.

[0109] Generally, in order to prevent electromagnetic wave leakage, it is necessary to make the distance between the door-side electromagnetic wave shield 26d when the door 29 is closed and the cross rail 21 that is the electromagnetic wave shield on the main body side of the refrigerator 1 (connected to the outer box 3, as Figure 1 shown) shorter than 1 / 4 of the wavelength λ of the electromagnetic wave. In the first embodiment, by further reducing the distance between the door-side electromagnetic wave shield 26d and the cross rail 21, the grounding effect of the electromagnetic wave shield can be obtained without providing a wired circuit between the door-side electromagnetic wave shield 26d and the cross rail 21. For example, the distance between the door-side electromagnetic wave shield 26d and the cross rail 21 when the door 29 is closed is set to be within 30 mm. Since the cross rail 21 connected to the outer box 3 is grounded, in the state where the door 29 is closed, the door-side electromagnetic wave shield 26d approaches the cross rail 21, and thus an effect equivalent to grounding based on a wired circuit can be obtained. In addition, by forming the end portion of the door-side electromagnetic wave shield 26d into a shape that bends toward the main body side of the refrigerator 1, the door-side electromagnetic wave shield 26d can be easily brought close to the cross rail 21.

[0110] In addition, a structure in which the door-side electromagnetic wave shield 26d approaches, for example, other electromagnetic wave shields 26 (26a, 26c) other than the cross rail 21 may be formed.

[0111] Next, the connection between the electromagnetic wave shield and other circuits and the ground wire will be described.

[0112] Figure 10 is a schematic circuit diagram of an AC (alternating current) / DC (direct current) converter that drives various circuits. In this circuit, as the DC / DC converter arranged after the bridge diode BD1 and the rectifier capacitor C0 that rectify the AC power frequency power supply ACV, a flyback type switching power supply circuit is used. However, the DC / DC converter is not limited to this, and any switching power supply using a transformer such as a forward type, a push-pull type, or a half-bridge type may be used. In addition, in Figure 10 only the main circuit components are shown in the circuit, and noise filters, power control circuits, protection circuits, etc. are omitted.

[0113] The AC power supply ACV is converted to DC by the bridge diode BD1 and the rectifying capacitor C0, and is referred to as the primary DC power supply DCV0 (first power supply). The zero volt reference potential of the primary DC power supply DCV0 is the primary ground GND0 (first ground).

[0114] Primary DC power supply DCV0 is applied to primary winding P1 of switching transformer T1 and switched at a frequency of several tens of kHz by FET (field effect transistor) Q1. The power stored in primary winding P1 is transferred to the electrically isolated secondary winding S1 through electromagnetic induction, where it is rectified by secondary rectifier diode D1 and capacitor C1, resulting in output of secondary DC power supply DCV1. Secondary winding S2, meanwhile, has an output section between its two ends. This is rectified by secondary rectifier diode D2 and capacitor C2, resulting in output of secondary DC power supply DCV2, which has a lower voltage than secondary DC power supply DCV1. The zero volt reference potential of these secondary DC power supplies DCV1 and DCV2 (second power supply section) serves as the secondary ground GND1 (second ground section).

[0115] Furthermore, primary-side DC power supply DCV0 is applied to switching transformer T1 and branched to primary winding P2 of switching transformer T2, where it is switched at a frequency of several tens of kHz by FET Q2. The power stored in primary winding P2 is transferred to the electrically insulated secondary winding S3 through electromagnetic induction. It is then rectified by secondary-side rectifier diode D3 and capacitor C3, resulting in output of secondary-side DC power supply DCV3 (third power supply). The zero volt reference potential of secondary-side DC power supply DCV3 serves as secondary-side ground GND2 (third ground).

[0116] The insulation between the primary winding P1 and the secondary winding S1 in the switching transformer T1 and the insulation between the primary winding P2 and the secondary winding S3 in the switching transformer T2 are formed to have insulation performance higher than the basic insulation specified by the Electrical Appliance and Material Safety Law of Japan or the IEC (International Electrotechnical Commission) standard.

[0117] like Figure 9As shown, in the oscillation circuit 22, a minute power of 40.68 MHz allocated to the ISM (Industrial, Scientific and Medical) band is output from the oscillation source 22a using a crystal or the like. After being slightly amplified by the first amplifier circuit 22b, it is further amplified by the second amplifier circuit 22c and output toward the matching circuit 23. In addition, the output frequency of the oscillation source 22a is not limited to 40.68 MHz.

[0118] In the present embodiment, the secondary-side DC power supply DCV1 is supplied to the second amplifier circuit 22c in the oscillation circuit 22, the secondary-side DC power supply DCV2 is supplied to the oscillation source 22a, the first amplifier circuit 22b, the incident reflection wave detection unit 51, and the matching circuit 23 in the oscillation circuit 22, and the secondary-side DC power supply DCV3 is supplied to the control unit 50.

[0119] Thus, the circuit system with the secondary-side ground GND1 set to the zero-volt reference potential becomes the oscillation circuit 22, the incident reflection wave detection unit 51, the matching circuit 23, and the second electrode 25. In addition, the circuit system with the secondary-side ground GND2 set to the zero-volt reference potential becomes the control unit 50.

[0120] The electromagnetic wave shielding member 26 (the top-side electromagnetic wave shielding member 26a, the back-side electromagnetic wave shielding member 26b, the bottom-side electromagnetic wave shielding member 26c, and the door-side electromagnetic wave shielding member 26d) is preferably insulated from the second electrode 25 (at the same potential as the secondary-side ground GND1), or in the case of non-insulation, it is connected at a position separated from the second electrode 25 by a certain distance or more. Thereby, the electric field and magnetic field applied to each electromagnetic wave shielding member are reduced, and leakage to the outside is also suppressed. That is, the effect of electromagnetic wave shielding is improved.

[0121] There are several means to improve the effect of electromagnetic wave shielding, and they will be described below.

[0122] One is a means of not connecting each electromagnetic wave shielding member to any of the primary-side ground GND0, the secondary-side ground GND1, and the secondary-side ground GND2. This means is particularly effective when the total area or total volume of the electromagnetic wave shielding member is a certain value or more, and it can suppress the leakage of high frequency to the outside through the ground wire and cause adverse effects as noise.

[0123] Another is a means of connecting each electromagnetic wave shielding member to the primary-side ground GND0. The primary-side ground GND0 is usually connected to the outer box 3 made of a metal material, and the grounding area is large. Therefore, since the zero-volt reference potential of the primary-side ground GND0 is the most stable, by connecting each electromagnetic wave shielding member to the primary-side ground GND0, not only the effect of each electromagnetic wave shielding member can be improved, but also malfunction caused by noise can be suppressed.

[0124] Another is a means of connecting each electromagnetic wave shielding member to the secondary side ground GND2. Since the second electrode 25 and each electromagnetic wave shielding member are insulated at two stages of the switching transformers T1 and T2, it is difficult for high-frequency noise to leak from the first electrode 24 to each electromagnetic wave shielding member, and the electric field between the first electrode 24 and the second electrode 25 is stable.

[0125] Another is a means of connecting each electromagnetic wave shielding member to the secondary side ground GND1. On the other hand, at a position more than a certain distance away from the second electrode 25, it is connected at least on the outside of each electromagnetic wave shielding member. A certain shielding effect can be obtained, and it is difficult for high-frequency noise to leak from the first electrode 24 to each electromagnetic wave shielding member, and the electric field between the first electrode 24 and the second electrode 25 is stable.

[0126] The above means of improving the shielding effect sometimes have different effects depending on the system configuration and wiring, etc. Therefore, it is necessary to select the optimal means considering the electric field generation efficiency from the first electrode 24 to the second electrode 25 and the electromagnetic wave shielding effect, etc.

[0127] In addition, in the refrigerator 1 of the first embodiment, the outer box 3 is made of a steel plate, so the steel plate itself has the function of an electromagnetic wave shielding member. Therefore, electromagnetic waves inside the refrigerator 1 are reliably prevented from leaking to the outside of the refrigerator 1.

[0128] In the above structure of the electromagnetic wave shielding member, malfunctions and radio wave leakage caused by normal mode noise generated in the system or common mode noise conducted to the secondary side ground wire GND1 or the secondary side ground wire GND2 sometimes become problems. In particular, the common mode noise overlaps with the cable that conducts the high-frequency output generated by the oscillation circuit 22, and there are many cases where noise is radiated from the cable surface. Therefore, a coaxial cable is usually used for the cable that conducts the high-frequency output. However, the common mode noise sometimes also conducts to the outside of the outer conductor that originally functions as a shield inside the coaxial cable.

[0129] Figure 19A and Figure 19B shows a structure for preventing malfunctions and radio wave leakage caused by common mode noise. In Figure 19A , the oscillation circuit 22 and the incident reflection wave detection unit 51 are arranged at a position away from the electrode holding substrate 52 including the matching circuit 23, etc. The coaxial cable 56a electrically connects the electrode holding substrate 52 and the incident reflection wave detection unit 51. The outer shell of the outer box 3a of the refrigerator 1 is made of a metal material. By wiring the coaxial cable 56a inside the outer box 3a, it is possible to suppress the leakage radio waves radiated due to the common mode noise conducted to the coaxial cable 56a from spreading to the outside of the refrigerator.

[0130] In Figure 19AIn this case, at least a part of the coaxial cable 56a is wired in a manner that contacts the inner side of the outer case 3a. The area of the outer case 3a is large and becomes a reference potential that is substantially the same as the potential of GND0 shown in Figure 10 . Therefore, by holding the coaxial cable 56a in such a manner that at least a part of the coaxial cable 56a contacts the inner side of the outer case 3a, the common-mode noise conducted to the coaxial cable 56a can escape toward the GND0 side.

[0131] In addition, in Figure 19B , the coaxial cable 56b is wired inside the outer case 3a, but is pasted on the wall surface of the inner case 4 or the air passage 12 in a manner that does not contact the inner side of the outer case 3a for wiring.

[0132] Regarding the structure of Figure 19A or the structure of Figure 19B , any structure is selected as the noise suppression structure in a manner that can suppress malfunction and radio wave leakage according to the path through which the common-mode noise is conducted in the coaxial cable 56a or the coaxial cable 56b and the outer case 3a.

[0133] In addition, the positional relationship between the coaxial cable 56a or the coaxial cable 56b and the outer case 3a is preferably wired in a manner that can be reliably formed by the holding member into the structure of Figure 19A or Figure 19B . Due to deviations during the mass production process, etc., the design that can form either of the wiring states of Figure 19A or Figure 19B is not ideal.

[0134] [1-7. Structure of the first electrode and the second electrode and thawing performance based on this configuration]

[0135] Figure 11 is a top view of the first electrode 24 and the second electrode 25 when observing the top surface side of the freezing / thawing chamber 6 from above.

[0136] As shown in Figure 11 , as the size of the first electrode 24, it is configured to have an area slightly smaller than that of the second electrode 25. In addition, a plurality of electrode holes 41 and 42 are formed in the first electrode 24 and the second electrode 25, respectively. The plurality of electrode holes 41 and 42 have a vertically long slit shape that extends from the back side of the storage chamber where the positive terminal 24a to 24c and the negative terminal 25a to 25c of the second electrode 25 are provided toward the front side. By setting it to such a shape, the high-frequency current input from the positive terminal 24a to 24c side easily flows from the back side of the storage chamber toward the front side, and the electric field strength generated between the two electrodes is slightly enhanced.

[0137] In the present embodiment, as shown in Figure 11As shown, the electrode holes 41 and 42 provided in the first electrode 24 and the second electrode 25 are not arranged at vertically symmetric positions, but are arranged at positions offset from each other by approximately half of the minor diameter of the electrode hole 41. Since a plurality of electrode holes 41 are formed in the electrode surface of the first electrode 24, the regions where the electric field is strongly formed in the electrode surface of the first electrode 24 are evenly dispersed. Therefore, dielectric heating of the stored object can be performed uniformly. That is, the edge portion of the opening portion in the electrode hole 41 becomes an electric field concentration region.

[0138] In addition, Figure 11 The shapes and arrangements of the electrode holes 41 and 42 shown are examples. The shapes and arrangements of the electrode holes 41 and 42 are appropriately designed in consideration of efficiency and manufacturing cost according to the specifications and structure of the refrigerator, etc. For example, the shapes of the electrode holes 41 and 42 can also be perfect circles. In addition, the electrode holes 41 of the first electrode 24 and the second electrode 25 are preferably arranged not at vertically symmetric positions, but offset from each other by approximately half of the hole diameter.

[0139] In addition, in the structure of Embodiment 1, the shape and arrangement of the electrode holes 41 of the first electrode 24 have been described with a structure in which a plurality of electrode holes 41 are arranged, but the present utility model is not limited to such a structure. For example, the first electrode 24 can also be in a shape with at least one opening portion. In this case, on the electrode surface of the first electrode 24, the edge portion of the opening portion becomes an electric field concentration region where the electric field is concentrated. As the present utility model, any structure that disperses the electric field concentration region in the electrode surface of the first electrode 24 is acceptable. In addition, in Embodiment 1, a structure in which a plurality of electrode holes 42 are provided in the electrode surface of the second electrode 25 has been described, but the present utility model is not limited to this structure. That is, as long as an opening is formed in the second electrode 25 in such a way that a desired electric field is formed between the electrodes of the first electrode 24.

[0140] The electrode holding substrate 52 is configured to reliably hold the first electrode 24 and the second electrode 25 at a predetermined distance ( Figure 8 of H). In the present embodiment, the electrode interval H is shorter than the long side dimension of the first electrode 24 ( Figure 11 of D). In addition, it is preferably configured such that the electrode interval H is shorter than the diameter of the first electrode when it is circular and the major axis when it is elliptical.

[0141] Figure 12 Shows the relationship between the electrode interval H (refer to Figure 8 ) between the first electrode 24 and the second electrode 25 and the electric field strength between the two electrodes. As Figure 12As shown, there is a tendency that the wider the electrode gap H is, the weaker the electric field strength becomes. In particular, if the electrode gap H exceeds H1 (100 mm), the electric field strength decreases significantly, and if it exceeds H2 (125 mm), the electric field strength decreases to a level where the heating ability based on high frequency cannot be obtained. Based on the above, the electrode gap H is preferably 100 mm or less and at least 125 mm or less is required.

[0142] The inventor performed a simulation of the electric field generation between electrodes using the freezing / thawing chamber 6 having the electrode structure of Embodiment 1 and the freezing / thawing chamber 6 having an electrode structure in which a second electrode 25 without an electrode hole is provided as a comparative example.

[0143] Figure 13A It is a diagram showing the simulation results in the electrode configuration based on the first electrode 24 or the second electrode 25 without an electrode hole. Figure 13B It is a diagram showing the simulation results in the electrode configuration based on the first electrode 24 or the second electrode 25 having an electrode hole. In Figure 13A and Figure 13B the darker parts are the regions where the electric field is concentrated. From these electric field simulation diagrams, it can be seen that compared with the electric field simulation diagram of Figure 13A , in the electric field simulation diagram of the induction heating structure of Figure 13B the concentration of the electric field is alleviated in the whole electrode, and the homogenization of the electric field is achieved.

[0144] As Figure 11 shown, the electrode holes 41 of the first electrode 24 and the electrode holes 42 of the second electrode 25 are arranged such that the central axes of the respective electrode holes extending in the vertical direction (opposite direction) do not coincide, whereby the concentration of the electric field in the whole electrode is alleviated. In addition, in the electrode structure in which the central axes of the electrode holes 41 of the first electrode 24 and the electrode holes 42 of the second electrode 25 extending in the vertical direction (opposite direction) coincide, compared with the structure using the second electrode 25 without an electrode hole, the concentration of the electric field is alleviated, and in particular, the concentration of the electric field at the corner part is alleviated.

[0145] In the freezing / thawing chamber 6 of the refrigerator 1 of Embodiment 1, as Figure 2 and Figure 3As shown, there is a structure in which a storage box 31 is fixed to the back side of the door 29, and the storage box 31 moves back and forth inside the freezing / thawing chamber 6 along with the opening and closing movement of the door 29. In the structure of the first embodiment, in order to enable the storage box 31 to move smoothly inside the freezing / thawing chamber 6, guide rails are provided on the inner sides of both side surfaces of the freezing / thawing chamber 6. In addition, sliding members that slide on these rails are provided on both outer side surfaces of the storage box 31. These guide rails and the sliding members of the frame (storage housing 31) are arranged at positions deviating from the region where the first electrode 24 and the second electrode 25 of the freezing / thawing chamber 6 face each other, that is, the dielectric heating region, so as not to be dielectrically heated.

[0146] [1-8. Heating treatment operation]

[0147] In the refrigerator 1 of the first embodiment, when an electric field generation instruction such as a thawing instruction is input, an electric field generation process is performed on the space between the first electrode 24 and the second electrode 25 of the freezing / thawing chamber 6. Through the electric field generation process, thawing of the stored item (frozen product) arranged between the first electrode 24 and the second electrode 25 is performed. In the present embodiment, as an operation mode in the freezing / thawing chamber 6 of the refrigerator 1, for the stored item arranged between the first electrode 24 and the second electrode 25, there are two or more of a freezing mode for freezing the stored item, a storage mode for maintaining the frozen state of the stored item, and a thawing mode for thawing the frozen stored item. In the electric field generation process in the first embodiment, as described later, the control unit 50 controls the dielectric heating mechanism having the oscillation circuit 22, the incident reflection wave detection unit 51, and the matching circuit 23, and controls the cooling mechanism including the compressor 19 and the cooler 13, etc. of the refrigeration cycle, and the cold air introduction mechanism including the cooling fan 14 and the air damper 12a, etc. The high-frequency electric power formed by the oscillation circuit 22 has mutually different output powers or output frequencies between the freezing mode, the storage mode, and the thawing mode.

[0148] In each of the freezing mode, the storage mode, and the thawing mode accompanied by the electric field generation process in the first embodiment, a prescribed high-frequency voltage is applied between the first electrode 24 and the second electrode 25, and the frozen product as a dielectric is dielectrically heated by the high-frequency electric field generated between the electrodes. In this dielectric heating, the control unit 50 performs opening and closing control of the air damper 12a, and cold air is introduced continuously or intermittently. Figure 14 Shows the waveforms of the control signals of the dielectric heating mechanism (oscillation circuit 22) and the cold air introduction mechanism (air damper 23) during the thawing process, and shows the food temperature, the chamber temperature of the freezing / thawing chamber 6, and the humidity of the freezing / thawing chamber 6 at this time.

[0149] In the case of a structure that uses VHF waves for electric field generation processing, as a characteristic of the frequency, "local cooking" is less likely to occur compared to the case of a structure that uses microwaves. In the refrigerator 1 of Embodiment 1, in order to achieve better thawing uniformity, an electrode holding substrate 52 is provided, and the first electrode 24 and the second electrode 25, which are substantially planar plate-like members, are reliably held at a prescribed interval ( Figure 8 H) and substantially parallel to each other by the electrode holding substrate 52.

[0150] As Figure 14 shown, for example, in the thawing process (thawing mode), when a thawing instruction is input (thawing start), the oscillation circuit 22 becomes conductive, and a high-frequency voltage of, for example, 40.68 MHz is applied between the first electrode 24 and the second electrode 25. At this time, since the air damper 12a is in the open state, the room temperature in the freezing / thawing chamber 6 is maintained at the freezing temperature t1 (e.g., -20°C). After a prescribed period has elapsed since the start of thawing, the air damper 12a is closed. When the air damper 12a is closed, the room temperature in the freezing / thawing chamber 6 starts to rise. In the thawing process of Embodiment 1, by controlling the opening and closing of the air damper 12a while performing dielectric heating, the rise in the surface temperature of the frozen product is suppressed, and thawing is performed without causing so-called "partial cooking".

[0151] The opening and closing control of the air damper 12a is performed by the control unit 50 based on the ratio (reflectivity) of the reflected wave detected by the incident reflected wave detection unit 51 to the incident wave. Here, the incident wave refers to the electromagnetic wave that is matched by the matching circuit 23 and supplied between the first electrode 24 and the second electrode 25. When the reflectivity increases and reaches a preset threshold value, the control unit 50 opens the air damper 12a to lower the temperature inside the freezing / thawing chamber 6. In this way, by controlling the opening and closing of the air damper 12a, cold air is intermittently introduced into the freezing / thawing chamber 6, so that the stored items in the storage space (electric field generation space) of the freezing / thawing chamber 6 are dielectrically heated while maintaining the desired frozen state and become the desired thawed state.

[0152] When the stored items reach the desired thawed state, the thawing process is completed. In order to detect the desired thawed state at which the thawing process is completed, reflectivity is used in the thawing process of Embodiment 1. When the stored items are melted by performing dielectric heating, the melted water molecules increase in the stored items. As the melted water molecules increase in the stored items, the dielectric constant changes, and the impedance matching state deviates. As a result, the ratio of the reflected wave to the output electromagnetic wave, that is, the reflectivity, increases. In the thawing process, when the reflectivity increases and reaches a preset threshold value, the matching circuit 23 performs impedance matching to reduce the reflectivity.

[0153] The detection of completion of thawing in the thawing process of Embodiment 1 is set to when the reflectance after impedance matching based on the matching circuit 23 exceeds the threshold for completion of thawing. The threshold for completion of thawing is set to the reflectance when the stored item thaws and reaches the desired thawed state. Here, the desired thawed state of the stored item means a state where a woman can cut the stored item with one hand and the amount of drip from the stored item is extremely small. The threshold for completion of thawing is a value obtained in advance through experiments.

[0154] In addition, as Figure 14 shown, by controlling the opening and closing of the damper 12a, cool air with a relatively low humidity that has passed through the air passage 12 is supplied from the cool air inlet hole 20 to the freezing / thawing chamber 6, so the humidity in the freezing / thawing chamber 6 does not become 100%. Therefore, condensation in the freezing / thawing chamber 6 is prevented.

[0155] Furthermore, the method for calculating the reflectance is not limited to the ratio (reflectance) of the reflected wave to the incident wave detected by the incident reflected wave detection unit 51. For example, the reflected wave may be detected by the detection unit, and the reflectance may be calculated as the ratio of this reflected wave to the output preset in the oscillation circuit 22.

[0156] In addition, the thawing process may be controlled without using the reflectance. For example, the thawing process may be controlled only by using the reflected wave detected by the incident reflected wave detection unit 51 regardless of the output. Additionally, these methods may also be used for the control using the reflectance described in the following description.

[0157] [1-9. Storage operation]

[0158] Figure 15 is a flowchart showing the control after the completion of the thawing process in the freezing / thawing chamber 6. In the Figure 15 shown control, cooling and electric field generation processes (storage mode) for making the food into an arbitrary state are performed. Figure 15 Each step shown in the flowchart is performed by the CPU (Central Processing Unit) of the control unit 50 executing a control program stored in a memory such as a ROM (Read Only Memory). As described above, when the reflectance after impedance matching based on the matching circuit 23 in the thawing process exceeds the threshold for completion of thawing, Figure 15Control after the thawing process is completed. For example, after the thawing process is completed, the stored item is maintained in the desired thawed state. One of the means is to set the room temperature of the freezing / thawing chamber 6 to a so-called micro-freezing temperature range, such as about -1°C to -3°C. Additionally, as another means, the room temperature of the freezing / thawing chamber 6 is set to the freezing temperature range, such as -18°C to -20°C, and a high-frequency electric field with reduced output is applied, or the high-frequency electric field is applied intermittently, thereby performing cooling and heating to maintain the stored item in the desired temperature range. Additionally, through the electric field generation process, the room temperature of the freezing / thawing chamber 6 can also be periodically changed. For example, by periodically changing the room temperature of the freezing / thawing chamber 6 within the temperature range of -12°C to -5°C, the composition of the food can be affected. In the present embodiment, cooling and heating are performed by applying a high-frequency electric field with reduced output or applying the high-frequency intermittently to maintain the stored item in the desired temperature range.

[0159] As Figure 15 As shown in step 101, after the storage process operation starts, the presence or absence of the stored item in the freezing / thawing chamber 6 is continuously detected (step 101). The detection of the presence or absence of the stored item in the freezing / thawing chamber 6 uses the continuously detected reflectivity. Therefore, the matching circuit 23 operates continuously, and electromagnetic waves with low output are intermittently output from the first electrode 24. The control unit 50 compares the reflectivity with a preset threshold for the presence or absence of the stored item to determine the presence or absence of the stored item in the freezing / thawing chamber 6.

[0160] In step 101, when it is detected that there is no stored item in the freezing / thawing chamber 6 (No in step 101), the room temperature of the freezing / thawing chamber 6 is set to the freezing temperature range, such as -18°C to -20°C (step 105).

[0161] In step 101, when it is detected that there is a stored item in the freezing / thawing chamber 6 (Yes in step 101), it is determined whether the existing stored item contains a non-frozen product after thawing based on the change in reflectivity.

[0162] Additionally, even after the thawing process of the stored item is completed, sometimes the user will not immediately take out the stored item from the freezing / thawing chamber 6. In such a case, the refrigerator 1 of Embodiment 1 is configured to maintain the micro-freezing temperature range that can maintain the desired thawed state of the stored item in the freezing / thawing chamber 6 for only a specified time. When the stored item is stored in the freezing / thawing chamber 6 for more than the specified time, in order to maintain the freshness of the stored item, in the refrigerator 1 of Embodiment 1, control is performed to transfer the room temperature of the freezing / thawing chamber 6 to the freezing temperature range. That is, in step 102, when it is determined that the time after the thawing is completed while the stored item in the thawed state remains stored in the freezing / thawing chamber 6 exceeds the specified time, it also transfers to step 105 to perform the freezing process of setting the room temperature of the freezing / thawing chamber 6 to the freezing temperature range.

[0163] When it is determined that the thawed non-frozen product is not stored in the freezing / thawing chamber 6 (No in step 102), in step 103, for example, when the food temperature (temperature of the stored item) exceeds the target temperature, a freezing operation is performed (step 105), and when it does not exceed, a process of generating an electric field to raise the temperature of the food ingredients is performed.

[0164] Describe a specific example of this control.

[0165] The refrigerator 1 of Embodiment 1 is configured to perform dielectric heating in a freezing process in which the room temperature of the freezing / thawing chamber 6 is maintained in the freezing temperature range, so as to freeze and store the food as the stored item in a desired state. Generally, in the case of frozen food, due to the moisture in the freezing / thawing chamber 6 and the moisture inside the food, frosting occurs on the inner surface of the food wrapping material. When such frosting occurs on the food surface, the food dries out and the taste becomes dry, and the food is not in a delicious and fresh state ("frostbite"). In order to prevent such a state, in the refrigerator 1 of Embodiment 1, a dielectric heating operation is performed simultaneously with the cooling operation.

[0166] Figure 16A and Figure 16B is a waveform diagram showing the states of the respective elements in the cooling operation. Figure 16A is a waveform diagram showing the cooling operation in the freezing storage of an existing refrigerator, Figure 16B is a waveform diagram showing the cooling operation performed in the freezing / thawing chamber 6 of the refrigerator 1 of Embodiment 1.

[0167] In Figure 16A , (1) is a waveform diagram showing the ON / OFF of the cooling operation. The ON / OFF of the cooling operation corresponds to, for example, the opening and closing of the air damper, or the ON (opening) and OFF (closing) operations of the compressor, etc. In Figure 16A , ON (opening) indicates a state in which cold air is introduced into the freezer, and OFF (closing) indicates a state in which the air damper is closed and the introduction of cold air into the freezer is cut off. Therefore, as shown in the waveform diagram of (2) in Figure 16A , the temperature of the food in the freezer vibrates greatly up and down around a preset freezing temperature T1 (for example, -20°C). As a result, evaporation and frosting of moisture are repeatedly performed on the surface of the food in the freezer, and a situation where the frozen state of the food that cannot be an optimal state occurs.

[0168] On the other hand, in Figure 16B showing the cooling operation of Embodiment 1, different from the existing cooling operation, the food is cooled and dielectric heating is performed. Figure 16B(1) is a waveform diagram showing the opening and closing operation of the air damper 12a. ON (open) indicates the open state of the air damper 12a, and cold air is introduced into the freezing / thawing chamber 6 through the air passage 12 from the cold air inlet hole 20. OFF (closed) indicates the closed state of the air damper 12a, cutting off the introduction of cold air into the freezing / thawing chamber 6. In the cooling operation of Embodiment 1, the introduction of cold air is carried out simultaneously with the dielectric heating, so the introduction time of cold air is set longer than that of the conventional example. That is, the cooling capacity during the cooling operation is increased.

[0169] Figure 16B (2) is a waveform diagram showing the operation state of the dielectric heating based on the drive control of the oscillation circuit 22. When the air damper 12a is in the open state, the dielectric heating is carried out simultaneously.

[0170] In the cooling operation of Embodiment 1, the dielectric heating is carried out with an output smaller than that of the thawing operation. The adjustment of the output power is carried out by the power supply to the oscillation circuit 22 or the PWM (Pulse Width Modulation) control of the oscillation circuit 22.

[0171] As a result, as Figure 16B (3) shows, the food temperature in the freezing / thawing chamber 6 is maintained at a preset freezing temperature T1 (for example, -20 °C), and the variation of the food temperature is suppressed.

[0172] According to experiments, if the variation of the food temperature is about 0.1 K or less, the generation of frost can be eliminated. At least, the less the variation of the food temperature, the more the generation of frost can be suppressed.

[0173] In addition, by carrying out the dielectric heating at the same frequency as that during thawing and with an output power smaller than that during thawing, there is an effect of suppressing the elongation of ice crystals inside the food. When the dielectric heating is carried out, the electric field is likely to be concentrated at the front end of the ice crystals generated inside the food. Therefore, even if the temperature in the freezing / thawing chamber 6 is below the maximum ice crystal formation zone, the ice crystals only slowly elongate.

[0174] As described above, in the refrigerator 1 of Embodiment 1, the dielectric heating operation is also carried out during the cooling operation in the frozen storage. Therefore, the frozen products as stored items can be frozen and stored in a desired state.

[0175] [1 - 10. Freezing operation]

[0176] In the refrigerator 1 of Embodiment 1, based on the instruction of the user from the operation unit 47 (refer to Figure 9 ), the unfrozen food newly put into the freezing / thawing chamber 6 in the refrigerator can be subjected to a freezing process (freezing mode). Figure 17 is a waveform diagram showing the states of the respective elements during the rapid cooling operation as the freezing process. In Figure 17In (a), it is a graph showing whether there is a stored item (food) in the freezing / thawing chamber 6. The determination of whether there is a stored item in the freezing / thawing chamber 6 is made based on the ratio (reflectivity) of the reflected wave detected by the incident reflected wave detection unit 51 to the output electromagnetic wave in the control unit 50. Figure 17 In (b), it shows that the control unit 50 intermittently acquires information from the matching circuit 23 and the incident reflected wave detection unit 51. Figure 17 In (c), it is a graph showing an example of the change in reflectivity. When the reflectivity is below the first threshold R1, the control unit 50 determines that the food as the stored item has been placed in the freezing / thawing chamber 6.

[0177] During the rapid cooling operation of the food stored in the freezing / thawing chamber 6, the rotational speeds of the compressor 19 and the cooling fan 14 of the cooling mechanism are increased to improve the cooling capacity for forced continuous operation. In addition, the air-conditioning introduction mechanism is driven and controlled so that the damper 12a of the air duct 12 communicating with the freezing / thawing chamber 6 is forced to be driven in a continuously open state, and cold air is introduced into the freezing / thawing chamber 6 (refer to Figure 17 (the waveform diagram in (d)).

[0178] During the rapid cooling operation, in order to suppress the elongation of ice crystals when the food temperature is in the maximum ice crystal formation zone (about -1°C to about -5°C), a dielectric heating operation is performed. The dielectric heating operation at this time is intermittently performed with an output of several tens of W or less and lower than that during thawing ( Figure 17 the period H in (e)). In order to start the dielectric heating operation, it is detected that the food temperature enters the maximum ice crystal formation zone. This detection is based on the increase in the change in reflectivity when the food passes through the latent heat region. In Embodiment 1, when the detected reflectivity becomes a preset second threshold R2, the dielectric heating operation is started (refer to Figure 17 (e)). In addition, the region where the reflectivity ranges from the second threshold R2 to the third threshold R3 lower than the second threshold R2 is used as the maximum ice crystal formation zone of the food, and the dielectric heating operation continues. When a specified time (t2) has elapsed since the reflectivity became the third threshold R3, the control unit 50 determines that the food has passed through the maximum ice crystal formation zone and stops the dielectric heating operation.

[0179] As described above, when it is determined that the food has passed through the maximum ice crystal formation zone, the dielectric heating operation is stopped, and the rapid cooling operation is ended and transferred to the normal cooling operation. In this way, when performing the rapid cooling operation, by performing the dielectric heating operation during the desired period, the food can also be made into a preferred frozen state.

[0180] [1-11. Safety Control Based on Door Switch]

[0181] In the present embodiment, as described above, in order to prevent electromagnetic waves from leaking to the outside of the refrigerator 1, an electromagnetic wave shielding member 26 is provided so as to surround the freezing / thawing chamber 6. Further, the outer box 3 is made of a steel plate, and the steel plate itself has a function as an electromagnetic wave shielding member. Therefore, as long as the door 29 is closed, electromagnetic waves can be prevented from leaking to the outside.

[0182] However, when the door 29 is opened, electromagnetic waves may leak from the opening. In addition, since the user puts his hand into the chamber through the opening, there is a concern about the influence of high frequency on the human body, and thus countermeasures are required.

[0183] Therefore, in the present embodiment, when the door opening / closing detection unit 55a (see Figure 9 ) that detects the opening of the door 29 detects that the door 29 is opened, the oscillation circuit 22 is stopped and the power supply to the first electrode 24 is stopped. In addition, generally, a plurality of doors are provided in the refrigerator. Here, when the electromagnetic wave shielding member 26 functions sufficiently, even if the door opening / closing detection unit 55b of the refrigerating chamber 5, the door opening / closing detection unit 55c of the ice making chamber 7, the door opening / closing detection unit 55d of the freezing chamber 8, or the door opening / closing detection unit 55e of the vegetable chamber 9 detects that the door of a storage chamber other than the freezing / thawing chamber 6 is opened, electromagnetic waves above a specified level will not leak to the outside. Therefore, the oscillation circuit 22 does not stop and continues to operate.

[0184] However, this is not limited to the case where the freezing / thawing chamber 6 cannot be sufficiently surrounded by the electromagnetic wave shielding member 26 due to design problems.

[0185] For example, when the electromagnetic wave shielding member 26 cannot be formed on the top surface portion of the freezing / thawing chamber 6, when the door of the storage chamber (the refrigerating chamber 5 in the layout of Figure 1 ) located above the freezing / thawing chamber 6 is opened, the oscillation circuit 22 is stopped. In addition, when the electromagnetic wave shielding member 26 cannot be formed on the bottom surface portion of the freezing / thawing chamber 6, when the door of the storage chamber (the freezing chamber 8 or the vegetable chamber 9 in the layout of Figure 1 ) located below the freezing / thawing chamber 6 is opened, the oscillation circuit 22 is stopped. In addition, when the electromagnetic wave shielding member 26 cannot be formed on the side surface portion of the freezing / thawing chamber 6, when the door of the storage chamber (the ice making chamber 7 in the layout of Figure 1 ) located on the side of the freezing / thawing chamber 6 is opened, the oscillation circuit 22 is stopped. In this way, by stopping the oscillation circuit 22 when the door of the storage chamber arranged in the direction where the electromagnetic wave shielding member 26 cannot be formed is opened, leakage of electromagnetic waves can be prevented.

[0186] As a means for stopping the oscillation circuit 22, there are the following means.

[0187] Figure 18AMeans for cutting off the power supply from the power supply unit 48 to the oscillation circuit 22 through the door opening / closing detection unit 55a. The door opening / closing detection unit 55a is a switching mechanism that conducts when the door 29 is closed and cuts off when the door 29 is opened. By cutting off the switch, the power supply to the oscillation circuit 22 is cut off, thereby reliably stopping the operation of the oscillation circuit 22.

[0188] Figure 18B Means for stopping the operation of the power control unit 48a of the control power supply unit 48 through the door opening / closing detection unit 55a. The door opening / closing detection unit 55a is the same switching mechanism as Figure 18A above. When the door 29 is opened, the power supply to the power control unit 48a stops, whereby the power supply from the power supply unit 48 to the oscillation circuit 22 is also cut off, and thus the operation of the oscillation circuit 22 stops. In the Figure 18B example shown, the operation of the oscillation circuit 22 is stopped by cutting off the power supply to the circuit in the power control unit 48a, but means for causing the overcurrent protection circuit in the power control unit 48a to recognize an overcurrent state and stop it, or means for recognizing that the power supply unit 48 has become an overloaded state and stopping it can also be used.

[0189] Figure 18C It is a structure that determines the open / closed state of the door 29 not only through the door opening / closing detection unit 55a but also through the magnetic sensor 55f. The magnetic sensor 55f outputs an open / closed signal of the door 29 to the control unit 50. The control unit 50 receives the signal from the magnetic sensor 55f and outputs an operation permission signal to the power control unit 48a. The door opening / closing detection unit 55a is also inserted between the magnetic sensor 55f and the control unit 50, which conducts when the door 29 is closed and cuts off when the door 29 is opened. Therefore, when the door 29 is opened, no signal is output from the magnetic sensor 55f, and as a result, the operation of the power supply unit 48 stops.

[0190] The structure of the conduction / cutting-off of the power supply or control signal described above is implemented by hardware, so it has high tolerance to high-frequency noise or external noise. Therefore, malfunction is not likely to occur.

[0191] In addition, in Figure 18B and Figure 18C , the door opening / closing detection unit 55a is a switching mechanism that conducts when the door 29 is closed and cuts off when the door 29 is opened. However, a means using a mechanism that is cut off when the door 29 is closed and conducts when the door 29 is opened can also be used. In this case, the H (High) / L (Low) logic for stopping the power control unit 48a needs to be inverted.

[0192] In addition, in the refrigerator of Embodiment 1, a structure having a freezing function and a thawing function for the freezing / thawing chamber 6 has been described, but it can also be configured as a thawing chamber having only a thawing function.

[0193] As described above, in the cold storage of the present utility model, a high-frequency electric field is generated between the first electrode and the second electrode to thaw the stored items in the storage chamber. This high-frequency electric field is homogenized in the thawing space of the freezing / thawing chamber, and dielectric heating as desired can be performed during the thawing process and the freezing process of the items held in the thawing space. Therefore, according to the present utility model, the items stored in the storage chamber can be frozen, stored, and thawed in a desired state. Thus, a cold storage with highly reliable cooling, storage, and thawing functions can be provided. That is, it has the excellent effect of being able to freeze and store items in a desired state and thaw the frozen items in a desired state in a short time. In addition, by using a dielectric heating mechanism composed of semiconductor elements, miniaturization can be achieved for a cold storage with a thawing function.

[0194] [2-1. Effects, etc.]

[0195] As described above, the cold storage in the embodiment of the present utility model includes: a storage chamber having a space capable of storing items; an oscillation unit that forms high-frequency electric power; and a first electrode and a second electrode that are disposed opposite to each other and are respectively connected to the oscillation unit, and receive the high-frequency electric power formed by the oscillation unit to generate an electric field in the storage chamber. The cold storage has, as operating modes in the storage chamber, any two or more of a freezing mode for freezing the items disposed between the first electrode and the second electrode, a storage mode for maintaining the frozen state of the items, and a thawing mode for thawing the frozen items. Thus, the cold storage can appropriately adjust the intensity of the electric field in each mode.

[0196] By having a dew condensation prevention unit that utilizes waste heat, even in a low-temperature environment such as during freezing or storage, the waste heat of the system can be utilized to prevent dew condensation and frost formation. Therefore, a small-sized and highly reliable cold storage with cooling and storage functions is provided.

[0197] As described above, the present utility model has been described in the embodiment with a certain degree of detail. However, the disclosed content of the embodiment changes in the details of the structure, and replacement, combination, and order change of the elements in the embodiment can be achieved without departing from the scope and concept of the claimed present utility model.

[0198] Industrial Applicability

[0199] In the cold storage of the present utility model, the freezing, storage, and thawing of items can be separately processed to form a desired state, improving the added value, reliability, and safety of the cold storage, etc., and having a high market value. Therefore, it can be appropriately applied to various cold storages.

[0200] Explanation of Reference Numerals

[0201] 1 Refrigerator

[0202] 2 Heat-insulating box

[0203] 3, 3a Outer box

[0204] 4 Inner box

[0205] 5 Refrigerating chamber

[0206] 6 Freezing / thawing chamber (storage chamber)

[0207] 7 Ice-making chamber

[0208] 8 Freezing chamber

[0209] 9 Vegetable chamber

[0210] 10 Machinery room

[0211] 11 Cooling chamber

[0212] 12 Air duct

[0213] 12a Damper

[0214] 13 Cooler

[0215] 14 Cooling fan

[0216] 15 Defrosting heater

[0217] 16 Drain pan

[0218] 17 Drain pipe

[0219] 18 Evaporation pan

[0220] 19 Compressor

[0221] 20 Cold air inlet hole

[0222] 21 Horizontal rail

[0223] 22 Oscillation circuit (oscillation part)

[0224] 22a Oscillation source

[0225] 22b First amplifier circuit

[0226] 22c Second amplifier circuit

[0227] 23 Matching circuit (matching part)

[0228] 24 First electrode

[0229] 24a, 24b, 24c Positive terminal

[0230] 25 Second electrode

[0231] Negative terminal 25a, 25b, 25c

[0232] 26 Electromagnetic wave shielding member (shielding portion)

[0233] 26a Top surface side electromagnetic wave shielding member

[0234] 26b Back surface side electromagnetic wave shielding member

[0235] 26c Bottom surface side electromagnetic wave shielding member

[0236] 26d Door side electromagnetic wave shielding member

[0237] 29 Door

[0238] 30 Electrode holding area

[0239] 31 Storage box

[0240] 32, 32a, 32b, 32c Inner surface member

[0241] 36 Gasket

[0242] 40 Heat insulating material

[0243] 41 Electrode hole (first electrode hole)

[0244] 42 Electrode hole (second electrode hole)

[0245] 47 Operation part

[0246] 48 Power supply part

[0247] 48a Power supply control part

[0248] 49 Temperature sensor

[0249] 50 Control part

[0250] 51 Incident and reflected wave detection part

[0251] 52 Electrode holding substrate

[0252] 53a High-frequency heating module

[0253] 54 Support column

[0254] 55a, 55b, 55c, 55d, 55e Door opening and closing detection part

[0255] 55f Magnetic sensor

[0256] 56a, 56b Coaxial cable

[0257] D Long side dimension of the first electrode

[0258] H, H1, H2 Setting interval (electrode interval).

Claims

1. A cold storage, characterized in that, Comprising: A storage room having a space capable of storing storage items; An oscillation unit that forms high-frequency electric power; And A first electrode and a second electrode that are arranged opposite to each other and are each connected to the oscillation unit, and receive the high-frequency electric power from the oscillation unit to generate an electric field in the storage room, wherein As an operation mode in the storage room, for the storage items arranged between the first electrode and the second electrode, there are any two or more of the following modes: A freezing mode for freezing the storage items; A storage mode for maintaining the frozen state of the storage items; and A thawing mode for thawing the frozen storage items.

2. The refrigerator according to claim 1, wherein: The high-frequency electric power formed by the oscillation unit has mutually different output powers or output frequencies among the freezing mode, the storage mode, and the thawing mode.

3. The refrigerator according to claim 1 or 2, wherein: It further includes a dew condensation prevention unit for preventing dew condensation of the devices located on the transmission path of the high-frequency electric power.

4. The refrigerator according to claim 1 or 2, wherein: It further includes a freezing state determination unit that determines the freezing state of the storage items arranged between the first electrode and the second electrode.

5. The refrigerator according to claim 3, wherein: It further includes a matching circuit that is connected to the oscillation unit and is arranged on an electrode holding substrate, The dew condensation prevention unit includes the matching circuit and can utilize the waste heat generated by the matching circuit.

6. The refrigerator according to claim 3, wherein: It further includes a freezing state determination unit that determines the freezing state of the storage items arranged between the first electrode and the second electrode.

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