JP7228789B2 - Refrigerator and its control method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having a freezing function and its control method, and more particularly to a refrigerator having a storage compartment capable of thawing frozen goods and its control method.

A general refrigerator has a freezer compartment, freezes ingredients and foods, and is used as a frozen product for long-term storage. Such frozen products are desired to be thawed in a short time and used for cooking in a thawed state that is as close to fresh as possible.

In order to thaw frozen products, there are natural thawing at room temperature and thawing with running tap water. It wasn't. In general households, microwave heating cookers, so-called microwave ovens, are used to thaw frozen foods in a short time. However, when a frozen food is thawed in a microwave oven, it can be thawed in a short period of time, but high-frequency energy concentrates on the previously thawed portion, making it impossible to thaw uniformly. In some cases, an undesirable thawing state such as Thus, when a frozen food is thawed using a microwave oven, it is not easy to obtain a desired high-quality thawed state. Here, the high-quality thawed state refers to a thawed state that does not taste good as food, such as "partially boiled".

Patent Literature 1 discloses a refrigerator provided with a high-frequency heating chamber configured to thaw frozen items while supplying cool air and irradiating microwaves. The refrigerator of Patent Document 1 has a structure in which the surface of the frozen product in the high-frequency heating chamber is covered with cold air, and the inside of the frozen product is thawed by irradiating the frozen product with microwaves.

JP-A-2002-147919

The refrigerator disclosed in Patent Document 1 is provided with a magnetron to generate microwaves, and is configured to irradiate frozen goods in a high-frequency heating chamber with microwaves to perform microwave heating. Since the refrigerator of Patent Document 1 is provided with a magnetron as microwave generating means and a cooling mechanism thereof, the refrigerator as a whole has a large configuration, and it is difficult to reduce the size of the refrigerator. In addition, since the frozen product in the high-frequency heating chamber is microwave-heated by irradiating microwaves from the antenna, it is difficult to uniformly heat the frozen product and thaw it in a desired state.

In conventional refrigerators, when food stored in a storage compartment at room temperature is frozen, moisture in the cold storage compartment and moisture inside the food causes frost formation on the inner surface of the food packaging material. When such a phenomenon of frost formation appears on the surface of food, the food becomes dry, the texture becomes dry, and the food loses its delicious and fresh state ("freezer burn"). It has been a problem in the art to carry out the freezing process so that such "freezer burn" does not occur.

INDUSTRIAL APPLICABILITY The present invention has a thawing function that can easily thaw frozen products to a high-quality state, and also stores stored products in a storage chamber in a desired state during freezing processing and cryopreservation processing. To provide a refrigerator capable of storing food and having excellent performance.

A refrigerator according to one aspect of the present invention includes
at least one storage compartment having a refrigerable storage space capable of accommodating stored items;
a cooling mechanism for forming cold air;
an air passage that guides cold air from the cooling mechanism to the storage chamber;
an oscillating electrode provided in the storage space;
a counter electrode provided in the storage space facing the oscillation electrode;
a high-frequency electric field forming section for forming a high-frequency electric field applied between the oscillation electrode and the counter electrode;
a cold air introduction mechanism provided in the air passage for guiding cold air formed by the cooling mechanism to the storage chamber;
a control unit that controls the cooling mechanism and the cold air introduction mechanism so as to introduce cold air from the air passage into the storage chamber when a high-frequency electric field is applied between the oscillation electrode and the counter electrode;
It has

According to one aspect of the present invention, there is provided a refrigerator control method comprising: inputting a thawing command to a frozen product stored in a storage compartment;
a step of applying a high-frequency electric field to an oscillating electrode and a counter electrode provided across the storage space of the storage chamber when a thawing command is input;
When a high-frequency electric field is applied between the oscillating electrode and the counter electrode, a cooling mechanism for forming cold air and a cold air introducing mechanism for introducing cold air into the storage chamber are controlled to introduce cold air into the storage chamber. and

According to the present invention, it has a thawing function that can easily thaw a frozen product to a high-quality state, and also stores the stored product stored in the storage chamber in a desired state during the freezing process and the cryopreservation process. It is possible to provide a refrigerator having excellent performance as a food storage.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the longitudinal section of the refrigerator of Embodiment 1 which concerns on this invention Longitudinal sectional view showing the freezing/thawing chamber in the refrigerator of Embodiment 1 FIG. 2 is a block diagram showing the configuration of the dielectric heating mechanism provided in the refrigerator of Embodiment 1; FIG. 4 shows an electrode holding area on the back side of the freezing/thawing chamber in the refrigerator according to the first embodiment; FIG. 2 is a top plan view of the oscillation electrode and the inner surface member on the top surface side of the freezing/thawing chamber in the refrigerator according to the first embodiment; FIG. 10 is a back view showing the counter electrode on the bottom side arranged to face the oscillation electrode in the refrigerator of the first embodiment; FIG. 4 is a plan view showing a modification of the oscillation electrode in the refrigerator of Embodiment 1; A cross-sectional view (a) schematically showing a dielectric heating structure provided with a counter electrode having no electrode holes, and an electric field simulation diagram ( b) Sectional view (a) schematically showing a dielectric heating structure provided with a counter electrode having an electrode hole, and electric field simulation diagram (b) showing the results of a simulation performed on the dielectric heating structure shown in (a) FIG. 4 is a diagram showing waveforms of control signals for an oscillator circuit and a damper in a thawing process, and also showing the food temperature, the room temperature of the freezing/thawing chamber, and the humidity of the freezing/thawing chamber at that time, in the configuration of the first embodiment; Flowchart showing control after thawing processing is completed in the freezing/thawing chamber in the configuration of the first embodiment Waveform diagram (a) showing the cooling operation during frozen storage in the conventional refrigerator, and waveform diagram (b) showing the cooling operation performed in the freezing/thawing chamber in the refrigerator of the first embodiment. FIG. 4 is a waveform diagram showing the state of each element during rapid cooling operation in the configuration of Embodiment 1;

BEST MODE FOR CARRYING OUT THE INVENTION A refrigerator having a freezing function will be described below as an embodiment of a refrigerator according to the present invention with reference to the accompanying drawings. In addition, the refrigerator of the present invention is not limited to the configuration of the refrigerator described in the following embodiments, and can be applied to a freezer having only a freezing function. It includes a variety of refrigerators and freezers with features. Therefore, in the present invention, a refrigerator is a structure provided with a refrigerating compartment and/or a freezing compartment.

Numerical values, shapes, configurations, steps, order of steps, and the like shown in the following embodiments are examples and do not limit the present invention. Among the constituent elements in the following embodiments, constituent elements that are not described in independent claims indicating the highest concept will be described as optional constituent elements. Note that, in the embodiment, the same reference numerals may be given to the same elements even in the modified examples, and the description thereof may be omitted. In addition, the drawings schematically show each constituent element as a subject for easy understanding.

First, various aspects of the refrigerator of the present invention will be illustrated.
A refrigerator according to a first aspect of the present invention comprises:
at least one storage compartment having a refrigerable storage space capable of accommodating stored items;
a cooling mechanism for forming cold air;
an air passage that guides cold air from the cooling mechanism to the storage chamber;
an oscillating electrode provided in the storage space;
a counter electrode provided in the storage space facing the oscillation electrode;
a high-frequency electric field forming section for forming a high-frequency electric field applied between the oscillation electrode and the counter electrode;
a cold air introduction mechanism provided in the air passage for guiding cold air formed by the cooling mechanism to the storage chamber;
a control unit that controls the cooling mechanism and the cold air introduction mechanism so as to introduce cold air from the air passage when a high-frequency electric field is applied between the oscillation electrode and the counter electrode;
It has The refrigerator of the first aspect configured in this way ensures that the freezing, freezing, and thawing of the stored items stored in the storage compartments is performed to maintain the desired high-quality state of the stored items. can be processed.

A refrigerator according to a second aspect of the present invention, in the first aspect, includes a reflected wave detection unit that detects a reflected wave returning from the oscillation electrode toward the high-frequency electric field generation unit,
The control unit may be configured to control the cooling mechanism and the cool air introduction mechanism based on a reflectance indicating a ratio of reflected waves to electromagnetic waves output from the oscillation electrode.

A refrigerator according to a third aspect of the present invention is, in the above-described first or second aspect, provided with an inner surface member forming an inner surface of the storage chamber, wherein the inner surface member is configured to face the oscillation electrode and the counter electrode. It may be configured to cover each electrode surface that does.

A refrigerator according to a fourth aspect of the present invention is the refrigerator according to the third aspect, wherein the inner surface member has a cold air introduction hole, and cold air in the air passage is introduced into the storage compartment from the cold air introduction hole. may be configured.

A refrigerator according to a fifth aspect of the present invention is the refrigerator according to any one of the first to fourth aspects, wherein the oscillation electrode is arranged on the top surface side of the heating chamber, and the counter electrode is arranged on the heating chamber. The oscillation electrode may be provided on the bottom side of the chamber, and an opening portion may be formed through which cold air from the air passage passes.

A control method for a refrigerator according to a sixth aspect of the present invention is a step of inputting a thawing command for a frozen product stored in a storage compartment;
a step of applying a high-frequency electric field to an oscillating electrode and a counter electrode provided across the storage space of the storage chamber when a thawing command is input;
When a high-frequency electric field is applied between the oscillating electrode and the counter electrode, a cooling mechanism for forming cold air and a cold air introducing mechanism for introducing cold air into the storage chamber are controlled to introduce cold air into the storage chamber. and In the refrigerator control method of the sixth aspect having such steps, the freezing, freezing, and thawing of the stored items stored in the storage compartment are performed to maintain the desired high-quality state of the stored items. can be treated with certainty.

A refrigerator control method according to a seventh aspect of the present invention is, in the sixth aspect, detecting a reflected wave returning from the oscillating electrode toward a high-frequency electric field forming portion that forms a high-frequency electric field;
and controlling introduction of cold air into the storage chamber based on a reflectance indicating a ratio of reflected waves to electromagnetic waves output from the oscillation electrode.

According to an eighth aspect of the present invention, there is provided a refrigerator control method according to the seventh aspect, wherein the thawing process in response to a thawing command for the frozen goods stored in the storage compartment is terminated based on the reflectance. good too.

A refrigerator control method according to a ninth aspect of the present invention may be such that in the eighth aspect described above, the storage compartment is held in a slightly freezing temperature zone after the thawing process in response to the thawing command is completed.

A refrigerator control method according to a tenth aspect of the present invention is a refrigerator control method according to any one of the sixth to ninth aspects described above, wherein the thawed stored product is stored in the refrigerator after the thawing processing in response to the thawing command is completed. When stored in the room for a predetermined period of time, the storage object may be subjected to freezing treatment.

A refrigerator control method according to an eleventh aspect of the present invention is a refrigerator control method according to any one of the sixth to tenth aspects, wherein freezing, freezing, and thawing of stored items stored in the storage chamber are performed. , a high-frequency electric field may be applied to the oscillation electrode and the counter electrode.

(Embodiment 1)
EMBODIMENT OF THE INVENTION Hereafter, Embodiment 1 which concerns on the refrigerator of this invention is described, referring drawings. FIG. 1 is a view showing a longitudinal section of refrigerator 10 of Embodiment 1. As shown in FIG. In FIG. 1 , the left side is the front side of refrigerator 10 and the right side is the back side of refrigerator 10 . The refrigerator 10 includes an outer case 1 mainly made of steel plate, an inner case 2 made of resin such as ABS, and a foamed heat insulating material (for example, , hard urethane foam) 40.

The heat-insulating box body of the refrigerator 10 has a plurality of storage compartments, and each storage compartment has a front-side opening provided with an openable/closable door. Each storage compartment is sealed to prevent cold air from leaking by closing the door. In refrigerator 10 of Embodiment 1, the uppermost storage compartment is refrigerating compartment 3 . Two storage compartments, an ice-making compartment 4 and a freezing/thawing compartment 5, are arranged side by side on both sides immediately below the refrigerating compartment 3. - 特許庁Further, a freezer compartment 6 is provided directly below the ice making compartment 4 and the freeze/thaw compartment 5, and a vegetable compartment 7 is provided at the lowest portion directly below the freezer compartment 6. - 特許庁Each storage compartment in refrigerator 10 of Embodiment 1 has the above-described configuration, but this configuration is an example, and the arrangement configuration of each storage compartment can be appropriately changed at the time of design according to specifications and the like.

The refrigerator compartment 3 is maintained at a non-freezing temperature, specifically a temperature range of 1° C. to 5° C., in order to refrigerate stored items such as food. The vegetable compartment 7 is maintained in a temperature range equal to or slightly higher than that of the refrigerator compartment 3, eg, 2°C to 7°C. The freezer compartment 6 is set to a freezing temperature range, for example, −22° C. to −15° C. for frozen storage. The freezing/thawing chamber 5 is normally maintained in the same freezing temperature range as that of the freezing chamber 6, and thawing processing for thawing stored items (frozen items) is performed according to a user's thawing command. Details of the configuration of the freezing/thawing chamber 5 and the thawing process will be described later.

A machine room 8 is provided in the upper part of the refrigerator 10 . The machine room 8 accommodates parts constituting the refrigerating cycle such as a compressor 9 and a dryer for removing moisture in the refrigerating cycle. Note that the arrangement position of the machine room 8 is not specified in the upper part of the refrigerator 10, but is appropriately determined according to the arrangement position of the refrigerating cycle, etc., and is in another area such as the lower part of the refrigerator 10. may be placed in

A cooling chamber 11 is provided behind the freezer compartment 6 and the vegetable compartment 7 in the lower region of the refrigerator 10 . The cooling chamber 11 includes a cooler 12, which is a component of a refrigeration cycle that generates cool air, and a cooling fan 13 that blows the cool air generated by the cooler 12 to each of the storage compartments (3, 4, 5, 6, 7). is provided. Cool air generated by the cooler 12 flows through air paths 18 connected to each storage compartment by the cooling fan 13 and is supplied to each storage compartment. A damper 19 is provided in the air passage 18 leading to each storage compartment, and each storage compartment is maintained in a predetermined temperature range by controlling the rotation speed of the compressor 9 and the cooling fan 13 and opening/closing control of the damper 19. be. A defrost heater 14 for defrosting frost and ice adhering to the cooler 12 and its surroundings is provided in the lower part of the cooling chamber 11 . A drain pan 15, a drain tube 16, and an evaporating dish 17 are provided below the defrosting heater 14, and have a structure for evaporating water generated during defrosting.

Refrigerator 10 of Embodiment 1 is provided with operation unit 47 (see FIG. 3 described later). The user can issue various commands to the refrigerator 10 through the operation unit 47 (eg, temperature setting of each storage compartment, rapid cooling command, thawing command, ice making stop command, etc.). Further, the operation unit 47 has a display unit for notifying the occurrence of an abnormality or the like. Note that the refrigerator 10 may be configured to have a wireless communication unit and connect to a wireless LAN network so that various commands are input from an external terminal of the user. Further, the refrigerator 10 may be configured to have a voice recognition unit so that the user can input commands by voice.

FIG. 2 is a longitudinal sectional view showing freeze/thaw chamber 5 in refrigerator 10 of Embodiment 1. As shown in FIG. The freezing/thawing chamber 5 is a freezer that holds food and other stored items stored in the freezing/thawing chamber 5 in a freezing temperature range. It becomes a thawing chamber for thawing by heating.

In the freezing/thawing chamber 5, the cool air generated in the cooler 12 passes through the air passages provided on the back side and the top side of the freezing/thawing chamber 5 so that it can be maintained in the same freezing temperature range as that of the freezing chamber 6. 18 and is introduced into the freezing/thawing chamber 5 through a plurality of cold air introduction holes 20 provided on the top surface of the freezing/thawing chamber 5 . A damper 19 is provided in an air passage 18 leading from the cooling chamber 11 to the freezing/thawing chamber 5, and the freezing/thawing chamber 5 is maintained in a predetermined freezing temperature range by opening/closing control of the damper 19. is stored frozen.

A cool air exhaust hole 21 is formed in the back surface of the freezing/thawing chamber 5 . The cold air that has been introduced into the freezing/thawing chamber 5 and has cooled the inside of the freezing/thawing chamber 5 returns to the cooling chamber 11 through the return air passage 34 from the cold air exhaust hole 21 and is cooled again by the cooler 12 . That is, refrigerator 10 of Embodiment 1 is configured such that cold air formed by cooler 12 is circulated.

The top surface, rear surface, both side surfaces and bottom surface of the freezing/thawing chamber 5 are formed of resin inner surface members 32 formed of an electrically insulating material. A door 29 is provided at the front opening of the freezing/thawing chamber 5 , and the storage space of the freezing/thawing chamber 5 is sealed by closing the door 29 . In the freezing/thawing chamber 5 of Embodiment 1, a storage case 31 with an open top is provided on the back side of the door 29, and the storage case 31 moves forward and backward at the same time when the door 29 is opened and closed in the front-rear direction. It is a configuration that By opening the door 29 in the forward direction, it becomes easy to put stored items such as food into and take them out from the storage case 31 .

Next, a description will be given of a dielectric heating mechanism that performs dielectric heating to defrost the stored material frozen in the freezing/thawing chamber 5 .

FIG. 3 is a block diagram showing the configuration of the dielectric heating mechanism provided in refrigerator 10 of Embodiment 1. As shown in FIG. The dielectric heating mechanism according to Embodiment 1 includes an oscillation circuit 22 that receives power from a power supply unit 48 and forms a predetermined high-frequency signal, a matching circuit 23, an oscillation electrode 24, a counter electrode 25, and a control unit 50. there is The oscillation circuit 22 configured using a semiconductor element is miniaturized and provided in the machine room 8 of the refrigerator 10 . The oscillator circuit 22 is electrically connected to the matching circuit 23 by a coaxial cable. The matching circuit 23 is arranged in the electrode holding area 30 (see FIG. 2), which is the space on the back side of the freezing/thawing chamber 5 . The oscillating circuit 22 and the matching circuit 23 serve as a high-frequency electric field forming section for forming a high-frequency electric field to be applied between the oscillating electrode 24 and the counter electrode 25 .

The oscillating electrode 24 is a planar electrode arranged on the ceiling side of the freezing/thawing chamber 5 . The counter electrode 25 is a planar electrode arranged on the bottom side of the freezing/thawing chamber 5 . The oscillating electrode 24 and the counter electrode 25 are arranged facing each other across the storage space (thawing space) of the freezing/thawing chamber 5, and are provided with an interval regulating portion 33 and the like, which will be described later in "Electrode Holding Mechanism". The facing interval is set to a preset predetermined interval (first interval). As a result, in the dielectric heating mechanism according to Embodiment 1, the oscillation electrode 24 and the counter electrode 25 are arranged substantially parallel. In the present invention, the term "substantially parallel" indicates a state of being essentially parallel, but includes an error caused by variations in processing accuracy or the like.

The oscillation electrode 24 is provided on one side of the storage space, and the counter electrode 25 is provided on the other side of the storage space across the storage space. The matching circuit 23 on the back side, the oscillating electrode 24 on the top side, and the counter electrode 25 on the bottom side, which constitute the dielectric heating mechanism, are covered with an inner surface member 32 to reliably prevent burns due to contact with stored items. be able to.

In the configuration of Embodiment 1, the oscillating electrode 24 is provided on the top surface portion forming the storage space of the freezing/thawing chamber 5, and the counter electrode 25 is provided on the bottom portion of the storage space of the freezing/thawing chamber 5. However, the present invention is not limited to this configuration. A similar effect can be obtained by arranging them facing each other in the direction.

As shown in FIG. 2 , the freezing/thawing chamber 5 is configured such that cold air from the cooler 12 is introduced from the ceiling side of the freezing/thawing chamber 5 through the air passage 18 . An oscillating electrode 24 is arranged on the lower surface of the air passage 18 on the top surface side of the freezing/thawing chamber 5 , and cold air from the cooling chamber 11 flows over the oscillating electrode 24 . Refrigerator 10 of Embodiment 1 has a heat insulating box formed by outer box 1, inner box 2, and a heat insulating material 40 filled and foamed between them. Dimensional accuracy is not high. In the space in which the freezing/thawing chamber 5 is formed, a region that becomes the air passage 18 is formed on the top side, so that the region that becomes the air passage 18 becomes a space that can absorb dimensional variations in the heat insulating box. . The cold air passing through the air passage 18 passes through a plurality of electrode holes 41 formed in the oscillating electrode 24 and is introduced into the freezing/thawing chamber 5 from the cold air introduction holes 20 of the inner surface member 32 on the top surface side. will be described later.

The oscillation circuit 22 outputs a high frequency voltage (40.68 MHz in the first embodiment) in the VHF band. When the oscillation circuit 22 outputs a high-frequency voltage, an electric field is formed between the oscillation electrode 24 and the counter electrode 25 to which the oscillation circuit 22 is connected, and the oscillation electrode 24 and the counter electrode 25 in the freezing/thawing chamber 5 are connected. A storage object, which is a dielectric placed in the intermediate storage space, is dielectrically heated.

The matching circuit 23 adjusts the load impedance formed by the oscillating electrode 24 , the counter electrode 25 , and the objects stored in the freezing/thawing chamber 5 to match the output impedance of the oscillating circuit 22 . The matching circuit 23 minimizes the reflected wave with respect to the output electromagnetic wave by matching the impedance. The dielectric heating mechanism according to Embodiment 1 is provided with a reflected wave detector 51 that detects a reflected wave returning from the oscillation electrode 24 toward the oscillation circuit 22 . Therefore, the oscillator circuit 22 is electrically connected to the oscillator electrode 24 via the reflected wave detector 51 and the matching circuit 23 . The control unit 50 determines the ratio (reflectance) of the reflected wave output to the electromagnetic wave output based on the electromagnetic wave output from the oscillation circuit 22 after impedance matching in the matching circuit 23 and the reflected wave detected by the reflected wave detection unit 51. is calculated, and various controls are performed based on the calculation result as will be described later.

As shown in the block diagram of FIG. 3, in the dielectric heating mechanism, the control unit 50 controls the oscillation circuit 22 based on the signals from the operation unit 47 for setting operation by the user and the temperature sensor 49 for detecting the internal temperature. and the matching circuit 23 are driven and controlled. The control unit 50 is composed of a CPU, and performs various controls by executing a control program stored in a memory such as a ROM.

It is desirable that the length of the wiring on the positive electrode side connecting the oscillation circuit 22, the matching circuit 23, and the oscillation electrode 24 is short. 5 may be arranged in the electrode holding area 30 on the back side.

[Electrode holding mechanism]
In the dielectric heating mechanism according to Embodiment 1 configured as described above, the plate-like oscillation electrode 24 and the counter electrode 25 face each other substantially in parallel. , the electric field is made uniform. In order to dispose the oscillating electrode 24 and the counter electrode 25 substantially parallel to each other with a predetermined interval (first interval), the dielectric heating mechanism according to the first embodiment employs an electrode holding mechanism, which will be described below. have a mechanism.

FIG. 4 is a diagram showing the electrode holding area 30 on the back side of the freezing/thawing chamber 5 in Embodiment 1, and shows the electrode holding mechanism in the electrode holding area 30. As shown in FIG. FIG. 4 is a view of the electrode holding area 30 viewed from the back side, and the oscillation electrode 24 is arranged on the upper side (top side) and the counter electrode 25 is arranged on the lower side (bottom side). A positive electrode terminal 24a protrudes from the center of the rear end portion of the plate-shaped oscillation electrode 24, and support members 24b, 24b protrude from both sides thereof. The positive electrode terminal 24a and the supporting member 24b are bent downward (bottom side) at a right angle from the back side end of the plate-shaped oscillation electrode 24 to protrude. Similarly, a negative electrode terminal 25a protrudes from the center of the back side end of the plate-shaped counter electrode 25, and support members 25b, 25b protrude from both sides thereof. The negative electrode terminal 25a and the supporting member 25b are bent at right angles upward (upper surface side) from the back side end portion of the flat counter electrode 25 so as to protrude. That is, the projecting ends of the positive electrode terminal 24a of the oscillation electrode 24 and the support member 24b are opposed to the projecting ends of the negative electrode terminal 25a of the counter electrode 25 and the support member 25b, respectively.

As described above, the direction in which the support members 24b and 24b of the oscillation electrode 24 protrude is opposed to the direction in which the support members 25b and 25b of the counter electrode 25 protrude. It is linearly joined to the supporting members 25b, 25b facing each other via the space defining portion 33. As shown in FIG. The interval defining portion 33 is a planar member and is formed of an electrically insulating member that is substantially not dielectrically heated. As shown in FIG. 4, the interval defining portion 33 has an H shape when viewed from the rear side, and support members (24b, 25b) are connected to four upper and lower ends of the H shape. A matching circuit 23 is fixed to the central portion of the shape. Accordingly, the oscillation electrode 24 and the counter electrode 25 are fixed to the upper and lower ends of the space defining portion 33 , and the matching circuit 23 is fixed to the central portion of the space defining portion 33 . 25, and matching circuit 23 are held securely. In this manner, the space defining portion 33 is configured to securely hold the oscillation electrode 24 and the counter electrode 25, which are substantially flat plate-like members, with a predetermined distance (first distance) therebetween. Since the matching circuit 23 is fixed to the central portion of the H-shape of the space defining portion 33, the rigidity of the space defining portion 33 is high. ) and can be cantilevered. Further, the space defining portion 33 may be configured to have the high-frequency electric field forming portions of the oscillation circuit 22 and the matching circuit 23 .

A positive terminal 24 a of the oscillation electrode 24 and a negative terminal 25 a of the counter electrode 25 are connected to respective connection terminals on the positive and negative sides of the matching circuit 23 . The connection between the positive terminal 24a and the negative terminal 25a and each connection terminal of the matching circuit 23 is surface contact connection having a predetermined contact area so as to ensure reliability even when a large current flows. In the first embodiment, in order to ensure a reliable surface contact connection, flat terminals are connected to each other by screwing. The connection between the terminals is not limited to screw connection, as long as it is a connection means that provides a reliable surface contact connection.

In Embodiment 1, the terminal width w (see FIG. 4) of the positive electrode terminal 24a protruding from the back-side end of the oscillation electrode 24 is larger than the electrode width W (see FIG. 4) of the back-side end of the oscillation electrode 24. is formed to be significantly thin (w<<W). This configuration is such that the heat generated in the matching circuit 23 is less likely to be conducted to the oscillating electrode 24, and heat conduction between the matching circuit 23 and the oscillating electrode 24 is suppressed. This is for suppressing the occurrence. Also in the counter electrode 25, the terminal width of the negative electrode terminal 25a is formed to be significantly narrower than the electrode width of the back side end portion of the counter electrode 25 where the negative terminal 25a protrudes, similarly to the terminal width of the positive electrode terminal 24a. It is By narrowing the terminal width of the negative electrode terminal 25a in this manner, heat conduction between the counter electrode 25 and the matching circuit 23 is suppressed.

As shown in FIGS. 2 and 4, the cold air that has frozen the stored material in the freezing/thawing chamber 5 passes through the cold air exhaust hole 21, the return air passage 34, the electrode holding area 30, and returns to the cooling chamber 11. is. Since the return air passage 34 is configured to pass through the electrode holding area 30 in this way, the cold air from the freezing/thawing chamber 5 is not emitted from the electrode holding area 30, and the electrode including the matching circuit 23 is cooled. Dew condensation in the holding area 30 is prevented.

In addition, in the configuration in which the oscillation circuit 22 is arranged in the electrode holding region 30, a cooling configuration may be employed in which a heat sink, which is a heat dissipation member in the oscillation circuit 22, is brought into contact with the return air passage 34 for cooling.

As described above, since the electrode holding mechanism is provided on the back side of the freezing/thawing chamber 5, the plate-like oscillation electrode 24 and the counter electrode 25 are configured to face each other substantially in parallel. Further, in the configuration of the first embodiment, an electrode holding mechanism is also provided on the front side of the freezing/thawing chamber 5 in order to further ensure that the oscillation electrode 24 and the counter electrode 25 face each other substantially in parallel. It is

As described above, the heat insulating box body of the refrigerator 10 includes the outer box 1 made of steel, the inner box 2 made of resin, and the space between the outer box 1 and the inner box 2 filled and foamed for heat insulation. material (for example, rigid urethane foam) 40 . The heat insulating box body of the refrigerator 10 is provided with a cross rail 35 which is a frame portion for defining the edge of the front opening of each storage compartment. The cross rail 35 of the frame is joined to a predetermined position of the outer case 1 and positioned with high accuracy with respect to the outer case 1 . Therefore, the position of the cross rail 35 with respect to the outer box 1 is not affected by the filled and foamed heat insulating material 40, and the position is highly accurate.

As shown in FIG. 2 , a cross rail 35 is provided on the front edge of the freezing/thawing chamber 5 , and the cross rail 35 defines the front opening of the freezing/thawing chamber 5 . This front side opening is opened and closed by the door 29 of the freezing/thawing chamber 5 . A gasket 36 is provided between the door 29 and the cross rail 35 to prevent cold air from leaking when the door is closed.

The electrode holding mechanism on the front side of the freezing/thawing chamber 5 utilizes a cross rail 35 that is a frame portion that precisely defines the front side opening of the freezing/thawing chamber 5 . A first holding claw 37 and a second holding claw 38, which are holding members, are integrally formed on the upper and lower substantially parallel frame members of the cross rail 35 with a predetermined interval therebetween. The first holding claw 37 and the second holding claw 38, which are holding members, may be configured to be joined to the cross rail 35, which is a frame.

The first holding claw 37, which is a holding member, is configured to be engaged so as to sandwich the front end of the oscillation electrode 24, and defines the position of the front end of the oscillation electrode 24. As shown in FIG. The second holding claw 38, which is a holding member, is configured to support the front end portion of the counter electrode 25, and defines the position of the front end portion of the counter electrode 25. As shown in FIG. The first holding claw 37 and the second holding claw 38 hold the front end portions of the oscillation electrode 24 and the counter electrode 25 with a predetermined gap (first gap) therebetween. Also, the first holding claw 37 and the second holding claw 38 hold the oscillation electrode 24 and the counter electrode 25 in an electrically insulated state.

Therefore, in the refrigerator 10 of Embodiment 1, the dielectric heating mechanism of the freezing/thawing chamber 5 is provided with electrode holding mechanisms on both the back side and the front side. It is possible to dispose them with a high facing distance, and it is also possible to reliably dispose them substantially in parallel with a predetermined distance (first distance). As a result, the dielectric heating mechanism of the freezing/thawing chamber 5 prevents unevenness of the high-frequency electric field on the electrode surface, makes the high-frequency electric field uniform, and uniformly performs the thawing process for the stored items (frozen items). is possible.

[Electromagnetic wave shielding mechanism]
As described above, in the freezing/thawing chamber 5, dielectric heating is performed by arranging the dielectric material to be stored in the atmosphere of the high-frequency electric field between the oscillation electrode 24 and the counter electrode 25. 5 is a configuration capable of emitting electromagnetic waves. In order to prevent this electromagnetic wave from leaking to the outside of refrigerator 10 , refrigerator 10 of Embodiment 1 is provided with an electromagnetic wave shielding mechanism so as to surround freeze/thaw chamber 5 .

As shown in FIG. 2 , a top-side electromagnetic wave shield 26 is arranged above the air passage 18 on the top side of the freezing/thawing chamber 5 . The top-side electromagnetic wave shield 26 is disposed on the upper surface of a heat insulating material 40 that constitutes the bottom side of the refrigerator compartment 3 directly above the freeze/thaw chamber 5, so as to cover the top surface side of the freeze/thaw chamber 5. are arranged. The top-surface-side electromagnetic wave shield 26 has a plurality of openings and is configured so that the substantial facing area with respect to the oscillation electrode 24 is small. The top surface side electromagnetic wave shield 26 configured in this way has a configuration in which generation of an unnecessary electric field is suppressed between itself and the oscillation electrode 24 . Note that the top-side electromagnetic wave shield 26 may have a mesh structure having a plurality of openings. Further, the top-side electromagnetic wave shield 26 may be provided inside the refrigerating chamber 3 located directly above the freezing/thawing chamber 5, but the refrigerating chamber 3 may be provided with a partial chamber or a chilled chamber. In many cases, the top surface of the partial room or chilled room may be used as an electromagnetic shield.

A back side electromagnetic wave shield 27 is arranged so as to cover the electrode holding area 30 having the matching circuit 23 and the like provided on the back side of the freezing/thawing chamber 5 . By providing the back-side electromagnetic wave shield 27 in this way, the electric field generated between the oscillation electrode 24 and the counter electrode 25 and the high-frequency noise generated from the matching circuit 23 affect the operation of the electrical components of the cooling fan 13 and the damper 19 ( control). An electromagnetic wave shield (not shown) is also provided on the side of the freezing/thawing chamber 5 .

Next, the door-side electromagnetic wave shield 39 provided on the door 29 that opens and closes the front opening of the freezing/thawing chamber 5 will be described. Since the door 29 is configured to open and close with respect to the main body of the refrigerator 10, in a configuration in which the electromagnetic shield provided on the door 29 is connected to the ground portion of the main body of the refrigerator 10 by a wired path, opening and closing of the door 29 extends the wired path. Shrinkage is repeated, and metal fatigue accumulates in the wire path. In such a configuration, it is not preferable to connect the electromagnetic wave shield 39 provided on the door 29 to the grounding portion of the main body of the refrigerator 10 by a wired path, because this causes disconnection in the wired path.

In general, in order to prevent electromagnetic wave leakage, when the door 29 is closed, the distance between the door side electromagnetic wave shield 39 and the body side electromagnetic wave shield cross rail 35 should be shorter than 1/4 of the wavelength λ of the electromagnetic wave. is necessary. In the first embodiment, by further reducing the distance, a contact effect can be obtained without providing a wired path. For example, the distance between the door-side electromagnetic wave shield 39 and the cross rail 35 when the door 29 is closed is 30 mm or less. Since the cross rail 35 connected to the outer casing 1 is grounded, the electromagnetic wave shield 39 on the door side is brought close to the cross rail 35 when the door 29 is closed. can get. In addition, by forming the edge portion of the door-side electromagnetic wave shield 39 into a shape bent toward the main body of the refrigerator 10 , the door-side electromagnetic wave shield 39 can be easily brought close to the cross rail 35 .

In refrigerator 10 of Embodiment 1, outer case 1 is made of a steel plate, so the steel plate itself functions as an electromagnetic wave shield. Therefore, electromagnetic waves inside the refrigerator 10 are reliably prevented from leaking to the outside of the refrigerator 10 .

[Structure of Oscillation Electrode and Counter Electrode]
When the user opens the door 29, high-humidity air flows from the outside into the freezing/thawing chamber 5 held in the freezing temperature range, and dew condensation is likely to occur inside the freezing/thawing chamber 5. - 特許庁If dew condensation occurs on the surfaces of the oscillation electrode 24 and the counter electrode 25, the electric field formation between the electrodes becomes unstable, and a state in which desired dielectric heating is not performed may occur. In order to prevent such a state, in the refrigerator 10 of the first embodiment, the oscillation electrode 24 and the counter electrode 25 are covered with the inner surface member 32, and introduction of cold air into the freezing/thawing chamber 5 is oscillated. It is configured to be supplied from a plurality of cool air introduction holes 20 formed in the electrode 24 . The cold air introduced into the freezing/thawing chamber 5 is the cold air sent from the cooling chamber 11 through the air passage 18 by the cooling fan 13, and the cold air at the time of introduction has relatively low humidity. . Therefore, even if the door 29 is opened and closed and high-humidity air flows in from the outside, low-humidity cold air is blown into the freezing/thawing chamber 5 from the plurality of cold air introduction holes 20 formed on the entire top surface side. Since the air in the freezing/thawing chamber 5 is discharged from the cold air exhaust hole 21 on the back side, the inside of the freezing/thawing chamber 5 is in a state where dew condensation is unlikely to occur.

FIG. 5 is a top plan view of the oscillation electrode 24 and the inner surface member 32 on the ceiling side of the freezing/thawing chamber 5. As shown in FIG. As shown in FIG. 5 , a plurality of electrode holes 41 are formed in the oscillation electrode 24 , and the plurality of electrode holes 41 are dispersed over the entire electrode surface of the oscillation electrode 24 . The electrode holes 41 are arranged substantially uniformly at regular intervals on the electrode surface of the oscillation electrode 24 . The electrode hole 41 of the oscillation electrode 24 is provided corresponding to the position of the cold air introduction hole 20 formed in the inner surface member 32 covering the lower surface of the oscillation electrode 24 . A hole diameter D of the electrode hole 41 is formed to be larger than a hole diameter d of the cold air introduction hole 20 of the inner surface member 32 (D>d).

Since a plurality of electrode holes 41 are substantially uniformly formed on the electrode surface of the oscillation electrode 24 at regular intervals, areas where a strong electric field is formed on the electrode surface of the oscillation electrode 24 are uniformly dispersed. It becomes the structure which can perform dielectric heating with respect to a preservation|save material uniformly. That is, the edge of the opening of the electrode hole 41 becomes an electric field concentration region. The shape and arrangement of the plurality of cool air introduction holes 20 and electrode holes 41 shown in FIG. It is appropriately designed in consideration of efficiency and manufacturing cost.

FIG. 6 is a back view showing the counter electrode 25 on the bottom side arranged to face the oscillation electrode 24. As shown in FIG. FIG. 6 is a view of the counter electrode 25 viewed from below, and an inner surface member 32 serving as the bottom surface of the freezing/thawing chamber 5 is arranged on the counter electrode 25 . As shown in FIG. 6 , on the electrode surface of the counter electrode 25 as well, similarly to the oscillation electrode 24 , a plurality of electrode holes 42 are substantially evenly formed at regular intervals. However, in the configuration of the first embodiment, electrode hole 42 of counter electrode 25 is formed at a position not facing electrode hole 41 of oscillation electrode 24 . That is, the position of the central axis extending in the vertical direction of the electrode hole 42 of the counter electrode 25 is shifted from the position of the central axis extending in the vertical direction of the electrode hole 41 of the oscillation electrode 24, and the electrode hole 42 of the counter electrode 25 and the oscillation The electrode holes 41 of the electrodes 24 are displaced in the vertical direction (opposing direction).

In the configuration of Embodiment 1, the shape and arrangement of the electrode holes 41 of the oscillation electrode 24 have been described as a configuration in which the plurality of electrode holes 41 are arranged substantially uniformly at regular intervals. For example, the oscillation electrode 24 may have a shape in which at least one opening is formed. It becomes a concentrated electric field concentration region. That is, according to the present invention, it is sufficient that the electric field concentration regions are dispersed on the electrode surface of the oscillation electrode 24 . Further, in Embodiment 1, the configuration in which the electrode surface of the counter electrode 25 is provided with the plurality of electrode holes 42 has been described, but the present invention is specific to the configuration in which the counter electrode 25 is provided with the plurality of electrode holes 42 . Any opening formed so as to form a desired electric field between the electrodes and the oscillation electrode 24 may be used.

FIG. 7 is a plan view showing an example as a modification of the oscillation electrode 24 in the first embodiment. The modification shown in FIG. 7A shows an example in which one opening is formed as the electrode hole 41A in the oscillation electrode 24. FIG. In Embodiment 1, the opening formed in the oscillation electrode 24 is used as an electrode opening, and the electrode opening includes electrode holes (41, 41A). The electrode opening 41A shown in (a) of FIG. 7 includes a circular opening 41a, an arcuate opening 41b, and a communication opening 41c that communicates the respective openings (41a, 41b). there is By forming the electrode opening 41</b>A in such a shape, it is possible to disperse the regions where the electric field is strong on the electrode surface of the oscillation electrode 24 . A modification shown in FIG. 7B shows a modification of the electrode opening (41B) in the oscillation electrode 24, and the electrode notch 41B is formed by forming a notch in the oscillation electrode 24. An example. As shown in FIG. 7(b), by forming the electrode notch 41B as the opening, the regions where the electric field is strong on the electrode surface of the oscillation electrode 24 are dispersed. The cold air introduction holes 20 formed in the inner surface member 32 covering the lower surface of the oscillation electrode 24 are formed at positions corresponding to the electrode openings (41, 41A, 41B) of the oscillation electrode 24. It is configured to smoothly introduce cold air into the freezing/thawing chamber 5. - 特許庁

As described above, on the top surface side of the freezing/thawing chamber 5 in Embodiment 1, cold air passes through the electrode openings (41, 41A, 41B), which are the opening portions of the oscillation electrode 24 that constitutes the lower surface of the air passage 18. is introduced into the freezing/thawing chamber 5 through . Therefore, the freezing/thawing chamber 5 is configured such that cold air is blown from the cold air introduction holes 20 formed on the top surface side, and uniform and rapid freezing processing can be performed in the freezing/thawing chamber 5 . Further, since the electric field concentration regions are formed so as to be dispersed on the electrode surface of the oscillation electrode 24, uniform dielectric heating can be performed on the stored object, and good thawing can be performed.

5 and 6 described above, the electrode hole 41 of the oscillation electrode 24 and the electrode hole 42 of the counter electrode 25 are formed so that the center axes extending in the vertical direction (opposing direction) do not coincide with each other. , the areas where the electric field is concentrated in the oscillation electrode 24 and the counter electrode 25 are dispersed, and the electric field is made uniform in the storage space where the oscillation electrode 24 and the counter electrode 25 face each other. As a result, the objects placed in the storage space of the freeze/thaw chamber 5 can be subjected to more uniform dielectric heating.

The inventor used the freezing/thawing chamber 5 having the electrode configuration of Embodiment 1 and, as a comparative example, the freezing/thawing chamber 5X having the electrode configuration provided with the counter electrode 25X having no electrode hole. , simulated the electric field generation between the electrodes.

FIG. 8(a) is a cross-sectional view schematically showing an electrode configuration in which a counter electrode 25X having no electrode hole is provided, and is a cross-sectional view of the freezing/thawing chamber 5X cut in the left-right direction. FIG. 8(b) shows the result of simulating the electric field strength when an electric field is applied to the electrodes having the electrode configuration shown in FIG. 8(a). In FIG. 8(b), dark colored portions are regions where the electric field is concentrated. As is clear from this electric field simulation diagram, the electric field is concentrated in the outer edge portion of the electrode, and particularly in the corner portion.

FIG. 9(a) is a cross-sectional view schematically showing the electrode configuration of the freezing/thawing chamber 5 having the configuration of Embodiment 1, and is a view of the freezing/thawing chamber 5 cut in the horizontal direction. FIG. 9(b) shows the result of simulating the electric field intensity when an electric field is applied to the electrodes having the electrode configuration shown in FIG. 9(a). In FIG. 9(b), similarly to FIG. 8(b), dark-colored portions are regions where the electric field is concentrated. As is clear from this electric field simulation diagram, compared to the electric field simulation diagram of FIG. 8(b), in the dielectric heating configuration of FIG. It can be understood that

As shown in FIG. 9B, by arranging the electrode hole 41 of the oscillation electrode 24 and the electrode hole 42 of the counter electrode 25 so that the center axes extending in the vertical direction (opposing direction) do not match, the electrode Electric field concentration is relaxed in the whole. In the electrode configuration in which the electrode hole 41 of the oscillation electrode 24 and the electrode hole 42 of the counter electrode 25 are arranged such that the central axes extending in the vertical direction (opposing direction) are aligned, the electrode hole shown in FIG. Concentration of the electric field was alleviated compared to the configuration in which the counter electrode 25X was not provided, and in particular the concentration of the electric field at the corner portion was alleviated.

In freezer/thaw chamber 5 in refrigerator 10 of Embodiment 1, storage case 31 is fixed to the rear side of door 29 as shown in FIG. The storage case 31 moves back and forth inside the freezing/thawing chamber 5 as the door 29 is opened and closed. In the configuration of Embodiment 1, rails 52 are provided on both sides of the freezing/thawing chamber 5 so that the storage case 31 can move smoothly inside the freezing/thawing chamber 5 (see FIG. 9). reference). Frames 53 that slide on the rails 52 are provided on both side surfaces of the storage case 31 . The sliding members of these rails 52 and frame 53 are provided at positions outside the dielectric heating region, which is the region where the oscillation electrode 24 and the counter electrode 25 of the freezing/thawing chamber 5 face each other, so that they are not dielectrically heated. there is

[Decompression processing]
In the refrigerator 10 of Embodiment 1, when a thawing command is input, a thawing process is performed on the stored items (frozen items) between the oscillation electrode 24 and the counter electrode 25 in the freezing/thawing chamber 5 . As will be described later, the thawing process in the first embodiment is performed by the control unit 50 controlling the dielectric heating mechanism having the oscillation circuit 22 and the matching circuit 23, and the cooling mechanism including the refrigerating cycle such as the compressor 9 and the cooler 12. , and the cool air introduction mechanism including the cooling fan 13 and the damper 19 .

In the thawing process in Embodiment 1, a predetermined high-frequency voltage is applied between the oscillation electrode 24 and the counter electrode 25, and the dielectric frozen product is dielectrically heated by the high-frequency electric field between the electrodes. During this dielectric heating, cold air is introduced intermittently by opening and closing the damper 19 . FIG. 10 shows the waveforms of the control signals for the dielectric heating mechanism (oscillation circuit 22) and cool air introduction mechanism (damper 19) during the thawing process, and also shows the food temperature, the room temperature of the freezing/thawing chamber 5, and the freezing/thawing temperature at that time. Humidity in chamber 5 is shown.

A configuration using VHF waves as a frequency characteristic for thawing processing is a configuration in which "partial boiling" is less likely to occur than a configuration using microwaves. In the refrigerator 10 of No. 1, the space defining portion 33 is provided to ensure that the oscillating electrode 24 and the counter electrode 25, which are substantially flat plate-like members, are substantially parallel to each other with a predetermined space (first space) therebetween. It is a configuration that holds

As shown in FIG. 10, in the thawing process, when a thawing command is input (to start thawing), the oscillation circuit is turned on, and a high frequency voltage of 40 MHz, for example, is applied between the oscillating electrode 24 and the counter electrode 25. be. At this time, since the damper 19 is open, the room temperature of the freezing/thawing chamber 5 is maintained at the freezing temperature t1 (eg, -20°C). The damper 19 is closed after a predetermined period of time has elapsed since the start of thawing. When the damper 19 is closed, the room temperature of the freezing/thawing chamber 5 begins to rise. In the thawing process according to the first embodiment, dielectric heating is performed and opening/closing control of the damper 19 is performed to suppress an increase in the surface temperature of the frozen product, thereby performing thawing without causing so-called "partially boiling". . The opening/closing control of the damper 19 is based on the ratio (reflectance) of the reflected wave detected by the reflected wave detector 51 to the electromagnetic wave matched by the matching circuit 23 and supplied between the oscillation electrode 24 and the counter electrode 25. is performed by the control unit 50. The controller 50 opens the damper 19 to lower the internal temperature of the freezing/thawing chamber 5 when the reflectance reaches a preset threshold value and becomes large. In this way, cold air is intermittently introduced into the freezing/thawing chamber 5 by opening/closing control of the damper 19, so that the stored items in the storage space (thawing space) of the freezing/thawing chamber 5 are maintained in a desired frozen state. It is then dielectrically heated to the desired thawed state.

Although the decompression process is completed when the desired decompression state is reached, reflectance is used in the decompression process of the first embodiment to detect the desired decompression state at which the decompression process is completed. . As the material to be stored is melted by dielectric heating, the number of melted water molecules in the material to be stored increases. As the number of melted water molecules in the stored material increases, the dielectric constant changes and the impedance matching state shifts. As a result, the reflectance, which is the ratio of the reflected wave to the output electromagnetic wave, increases. In the decompression process, when the reflectance increases and reaches a preset threshold, the matching circuit 23 performs impedance matching to reduce the reflectance.

Decompression completion in the decompression process of the first embodiment is detected when the reflectance after impedance matching by the matching circuit 23 exceeds the decompression completion threshold. The Thaw Complete Threshold detects when the thaw of the stored item has reached the desired state of thaw. Here, the thawed state in which it is desirable to thaw the preserved article is a state in which a woman can cut the preserved article with one hand and the amount of drip from the preserved article is very small. The threshold for the completion of thawing is a value obtained in advance by experiments.

As shown in FIG. 10, by controlling the opening and closing of the damper 19, cold air with relatively low humidity that has passed through the air passage 18 is supplied from the cold air introduction hole 20 to the freezing/thawing chamber 5. / The humidity in the thawing chamber 5 does not reach 100%, and dew condensation in the freezing/thawing chamber 5 is prevented.

[Control after completion of defrosting process]
FIG. 11 is a flow chart showing the control after the thawing process is completed in the freezing/thawing chamber 5. As shown in FIG. Each step shown in the flowchart of FIG. 11 is performed by the CPU of the control unit 50 executing a control program stored in a memory such as a ROM. As described above, when the reflectance after performing impedance matching by the matching circuit 23 in the decompression process exceeds the decompression completion threshold, the control after completion of the decompression process shown in FIG. 11 is performed.

As shown in step 101 of FIG. 11, after the thawing process is completed, the room temperature of the freezing/thawing chamber 5 is maintained in a so-called slightly freezing temperature range, eg, approximately -1°C to -3°C. By maintaining the freezing/thawing chamber 5 in the slightly freezing temperature range in this manner, the stored material is maintained in a desired thawed state. In the state where the freezing/thawing chamber 5 is maintained at the slightly freezing temperature, the presence or absence of the preserved object in the freezing/thawing chamber 5 is constantly detected (step 102). The detection of the presence or absence of the preserved object in the freezing/thawing chamber 5 uses reflectance that is constantly detected. Therefore, the matching circuit 23 is always intermittently operated, and low-power electromagnetic waves are intermittently output from the oscillation electrode 24 . The control unit 50 compares the reflectance with a preset threshold for the presence/absence of a storage object, and determines the presence/absence of the storage object in the freezing/thawing chamber 5 .

In step 102, when it is detected that there is no storage object in the freezing/thawing chamber 5, it is determined that the storage object in the desired thawed state has been taken out, and the room temperature of the freezing/thawing chamber 5 is changed to the freezing temperature range. , for example, −18° C. to −20° C. (step 105).

In step 102, when it is detected that there are stored items in the freezing/thawing chamber 5, it is determined whether or not the existing stored items include new non-frozen items (for example, foodstuffs at room temperature). be. Whether or not the freeze/thaw chamber 5 contains new non-frozen products is determined by the change in reflectance. When it is determined in step 103 that a new non-frozen product has been put into the freezing/thawing chamber 5, the room temperature of the freezing/thawing chamber 5 is set to the freezing temperature range (step 105).

On the other hand, when it is determined in step 103 that no new non-frozen product is stored in the freezing/thawing chamber 5 and the stored product in the thawed state is still being held, the time after completion of thawing is determined. It is determined whether or not the predetermined time has passed (step 104). Even if the thawing process for the stored item is completed, the user may not immediately take out the stored item from the freeze/thaw chamber 5 . In such a case, the refrigerator 10 of Embodiment 1 is configured such that a slightly freezing temperature range capable of maintaining a desired thawed state for the stored items in the freeze/thaw chamber 5 is maintained for a predetermined period of time. In the case where the stored material has been stored for more than this predetermined time, in order to maintain the freshness of the stored material, in the refrigerator 10 of Embodiment 1, the room temperature of the freezing/thawing chamber 5 is shifted to the freezing temperature range. are controlled. In step 104, if it is determined that the time after the completion of thawing has exceeded the predetermined time while the thawed stored material is stored, the process proceeds to step 105, where the room temperature of the freezing/thawing chamber 5 is changed to the freezing temperature. A freezing process is performed as a band.

As described above, in the refrigerator 10 of the first embodiment, after the thawing process is completed, the stored food in the desired thawed state can be held for a predetermined time so as to maintain freshness. Appropriate temperature control can be performed for the stored items inside the thawing chamber 5 .

[Freezing storage operation in the freezing/thawing chamber]
Refrigerator 10 of Embodiment 1 performs dielectric heating so as to freeze-preserve foods, which are stored items, in a desired state during freezing processing in which the room temperature of freezing/thawing chamber 5 is maintained in the freezing temperature range. It is configured. In general, when food is frozen, frost formation occurs on the inner surface of the food packaging material due to the moisture in the freezer/thaw chamber 5 and the moisture inside the food. When such a phenomenon of frost formation appears on the surface of food, the food becomes dry, the texture becomes dry, and the food loses its delicious and fresh state ("freezer burn"). In order to prevent such a state, in the refrigerator 10 of Embodiment 1, the dielectric heating operation is performed simultaneously with the cooling operation.

FIG. 12 is a waveform diagram showing the state of each element during cooling operation. FIG. 12(a) is a waveform diagram showing the cooling operation during frozen storage in the conventional refrigerator, and FIG. 12(b) shows the cooling operation performed in the freezing/thawing chamber 5 in the refrigerator 10 of Embodiment 1. It is a waveform diagram.

In FIG. 12(a), (1) is a waveform diagram showing ON/OFF of the cooling operation. The ON/OFF of the cooling operation corresponds to, for example, the opening and closing of a damper, the ON (ON) and OFF (OFF) of a compressor, and the like. ON indicates a state in which cool air is introduced into the freezer compartment, and OFF indicates a state in which the damper is closed to block the introduction of cool air into the freezer compartment. Therefore, as shown in the waveform diagram (2) of FIG. 12(a), the temperature of the food in the freezer compartment fluctuates greatly up and down around the preset freezing temperature (eg, -20°C) T1. . As a result, moisture evaporation and frost formation are repeated on the surface of the food in the freezer compartment, and the food may not be in a preferable frozen state.

On the other hand, in FIG. 12(b) showing the cooling operation of Embodiment 1, unlike the conventional cooling operation, food is cooled and dielectrically heated. (1) of FIG. 12B is a waveform diagram showing the opening and closing operation of the damper 19, ON (ON) shows the open state of the damper 19, and cold air passes through the air passage 18 and enters the cold air introduction hole 20. / is introduced into the thawing chamber 5 . OFF indicates the closed state of the damper 19, and the introduction of cool air to the freezing/thawing chamber 5 is cut off. Since cool air is introduced in the cooling operation of the first embodiment at the same time as dielectric heating, the cool air introduction time is set longer than in the conventional example, that is, the cooling capacity is increased.

(2) of FIG. 12(b) is a waveform diagram showing an operating state of dielectric heating when the oscillation circuit 22 is driven and controlled. When the damper 19 is open, dielectric heating is simultaneously performed. In the cooling operation in Embodiment 1, dielectric heating is performed with much smaller output than in the defrosting operation. As a result, as shown in (3) of FIG. 12(b), the food temperature in the freezing/thawing chamber 5 is maintained at the preset freezing temperature (for example, −20° C.) T1, and the food temperature fluctuates. is suppressed.

According to experiments, frost formation could be eliminated if the food temperature fluctuation was about 0.1 K or less. At least, the more the food temperature fluctuations are reduced, the more the occurrence of frost formation can be suppressed. Moreover, inside the food, dielectric heating has the effect of suppressing the elongation of ice crystals. When dielectric heating is performed, the electric field tends to gather at the tips of the ice crystals generated in the food. only extends.

As described above, in the refrigerator 10 of Embodiment 1, the dielectric heating operation is performed even during the cooling operation during frozen storage. becomes.

[Freezing]
In the refrigerator 10 of Embodiment 1, it is possible to freeze non-frozen food newly put into the freezer/thaw chamber 5 based on the user's command from the operation unit 47 . be. FIG. 13 is a waveform diagram showing the state of each element in the rapid cooling operation, which is freezing processing. In FIG. 13, (a) is a graph showing whether or not there is a preserved object (food) in the freezing/thawing chamber 5. FIG. Whether or not there is an object to be stored in the freezing/thawing chamber 5 is determined by the control unit 50 based on the ratio (reflectance) between the reflected wave detected by the reflected wave detection unit 51 and the electromagnetic wave output. be done. (b) of FIG. 13 shows that the control section 50 intermittently acquires information from the matching circuit 23 and the reflected wave detection section 51 . (c) of FIG. 13 is a graph showing an example of transition of the reflectance. The control unit 50 determines that food, which is a storage product, has been put into the freezing/thawing chamber 5 when the reflectance is equal to or less than the first threshold value R1.

In the rapid cooling operation for the food stored in the freezing/thawing chamber 5, the rotational speeds of the compressor 9 and the cooling fan 13 of the cooling mechanism are increased to enhance the cooling capacity and perform forced continuous operation. Further, the damper 19 of the air passage 18 leading to the freezing/thawing chamber 5 is forcibly driven in a continuous open state, and the cool air introduction mechanism is driven and controlled so that cool air is introduced (Fig. 13(d). (see waveform chart).

In the rapid cooling operation, a dielectric heating operation is performed in order to suppress the expansion of ice crystals when the food temperature is in the maximum ice crystal formation zone (approximately -1°C to approximately -5°C). The dielectric heating operation at this time is a low output of about 1 W to about 10 W, and the dielectric heating is performed intermittently (period H in FIG. 13(e)). Detection of the food temperature entering the zone of maximum ice crystallization to initiate dielectric heating operation is detected by an increase in change in reflectance as the food passes through the latent heat region. In Embodiment 1, the dielectric heating operation is started when the detected reflectance reaches the preset second threshold value R2 (see FIG. 13(e)). In addition, the dielectric heating operation is continued in the region where the reflectance is from the second threshold value R2 to the third threshold value R3, assuming that it is the maximum ice crystal formation zone of the food. When (t2) has passed, it is determined that the food has passed through the maximum ice crystal formation zone, and the dielectric heating operation is stopped.

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, the rapid cooling operation is terminated, and the normal cooling operation is started. In this manner, the food can be brought into a preferable frozen state by performing the dielectric heating operation for a desired period even when the rapid cooling operation is performed.

As described above, in the freeze/thaw chamber 5 of the refrigerator according to Embodiment 1, freezing and frozen storage can be performed in a desired state, and the frozen product in the desired state can be thawed to the desired state in a short time. By using a dielectric heating mechanism composed of a semiconductor element, the size of a refrigerator having a thawing function can be reduced.

In the refrigerator of the first embodiment, the freezing/thawing chamber 5 has a freezing function and a thawing function.

As described above, in the refrigerator of the present invention, as described in Embodiment 1, it has a thawing function that can easily thaw frozen products to a high-quality state, and in freezing processing and cryopreservation processing, It also has excellent performance as a food storage that stores the stored items in the storage chamber in a desired state. Therefore, according to the present invention, it is possible to freeze, store, and thaw stored items housed in the storage chamber in a desired state, and have highly reliable cooling, storage, and thawing functions, and a highly safe refrigerator. A refrigerator can be provided.

As described above, in the refrigerator of the present invention, it is possible to perform frozen storage in a desired state, and it is possible to thaw frozen products in a desired state to a desired state in a short time. By using a dielectric heating mechanism composed of a semiconductor element, the refrigerator having a thawing function can be made compact.

Although the present invention has been described with a certain degree of detail in the embodiments, the disclosure of the embodiments is subject to change in details of construction, and the substitution, combination and order of elements in the embodiments are subject to change. may be made without departing from the scope and spirit of the claimed invention.

In the refrigerator of the present invention, since it has a configuration that allows each of the freezing, storage, and thawing of the stored items to be in the desired state, it is a configuration that increases the added value of the refrigerator. It has market value.

1 Outer box 2 Inner box 3 Cold room 4 Ice making room 5 Freezing/thawing room 6 Freezing room 7 Vegetable room 8 Machine room 9 Compressor 10 Refrigerator 11 Cooling room 12 Cooler 13 Cooling fan 14 Defrost heater 15 Drain pan 16 Drain tube 17 Evaporation dish 18 Air passage 19 Damper 20 Cold air introduction hole 21 Cold air exhaust hole 22 Oscillation circuit 23 Matching circuit 24 Oscillation electrode 25 Counter electrode 26 Top surface side electromagnetic wave shield 27 Rear side electromagnetic wave shield 28 Front side electromagnetic wave shield 29 Door 30 Electrode holding area 31 Storage case 32 Inner surface member 33 Space regulation part 34 Return air path 39 Door side electromagnetic wave shield 40 Heat insulating material 41 Electrode hole (oscillation electrode)
42 electrode hole (counter electrode)
47 operation unit 48 power supply unit 49 temperature sensor 50 control unit 51 reflected wave detection unit

Claims (8)

at least one storage compartment having a refrigerable storage space capable of accommodating stored items;
a cooling mechanism for forming cold air;
an air passage that guides cold air from the cooling mechanism to the storage chamber;
an oscillating electrode provided in the storage space;
a counter electrode provided in the storage space facing the oscillation electrode;
a high-frequency electric field forming section for forming a high-frequency electric field applied between the oscillation electrode and the counter electrode;
a cold air introduction mechanism provided in the air passage for guiding cold air formed by the cooling mechanism to the storage chamber;
a control unit that controls the cooling mechanism and the cold air introduction mechanism so as to introduce cold air from the air passage when a high-frequency electric field is applied between the oscillation electrode and the counter electrode;
an inner surface member that constitutes the inner surface of the storage chamber and covers the opposed electrode surfaces of the oscillation electrode and the counter electrode ;
The refrigerator, wherein the inner surface member has a cold air introduction hole, and the cold air in the air passage is introduced into the storage compartment through the cold air introduction hole. at least one storage compartment having a refrigerable storage space capable of accommodating stored items;
a cooling mechanism for forming cold air;
an air passage that guides cold air from the cooling mechanism to the storage chamber;
an oscillating electrode provided in the storage space;
a counter electrode provided in the storage space facing the oscillation electrode;
a high-frequency electric field forming section for forming a high-frequency electric field applied between the oscillation electrode and the counter electrode;
a cold air introduction mechanism provided in the air passage for guiding cold air formed by the cooling mechanism to the storage chamber;
a control unit that controls the cooling mechanism and the cold air introduction mechanism so as to introduce cold air from the air passage when a high-frequency electric field is applied between the oscillation electrode and the counter electrode;
a reflected wave detector that detects a reflected wave returning from the oscillation electrode toward the high-frequency electric field generator;
The refrigerator , wherein the control unit is configured to control the cooling mechanism and the cool air introduction mechanism based on a reflectance indicating a ratio of reflected waves to electromagnetic waves output from the oscillation electrode. The oscillation electrode is arranged on the top surface side of the storage chamber, the counter electrode is arranged on the bottom surface side of the storage chamber, and an opening is formed in the oscillation electrode through which cold air from the air passage passes. 3. The refrigerator according to claim 1 or 2 . a step of inputting a thawing command for a frozen product stored in a storage room;
a step of applying a high-frequency electric field to an oscillating electrode and a counter electrode provided across the storage space of the storage chamber when a thawing command is input;
When a high-frequency electric field is applied between the oscillating electrode and the counter electrode, a cooling mechanism for forming cold air and a cold air introducing mechanism for introducing cold air into the storage chamber are controlled to introduce cold air into the storage chamber. and
detecting a reflected wave returning from the oscillating electrode toward a high-frequency electric field forming portion that forms a high-frequency electric field;
a step of controlling the introduction of cold air into the storage chamber based on the reflectance indicating the ratio of the reflected wave to the electromagnetic wave output from the oscillation electrode;
Refrigerator control method including. 5. The method of controlling a refrigerator according to claim 4 , wherein the thawing process for a thawing command for the frozen goods stored in the storage compartment is terminated based on the reflectance. 6. The method of controlling a refrigerator according to claim 5 , further comprising maintaining said storage compartment in a slightly freezing temperature zone after completing a thawing process in response to a thawing command. 7. Any one of claims 4 to 6 , wherein when the thawed storage material has been continuously stored in the storage chamber for a predetermined time since the thawing process in response to the thawing command is completed, the storage material is subjected to the freezing process. 1. The control method of the refrigerator according to 1. 8. The method according to any one of claims 4 to 7 , wherein a high-frequency electric field is applied to said oscillation electrode and said counter electrode during freezing, freezing, and thawing of an article stored in a storage chamber. refrigerator control method.

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