Thawing machine

Abstract

To suppress the occurrence of a surface temperature distribution in an object to be thawed.SOLUTION: A thawing machine of the present disclosure includes a housing, a conductor partition wall provided in the housing so as to form a high-frequency space in which a high frequency is confined, a thawing chamber partition wall provided in the conductor partition wall so as to form a thawing chamber in which an object to be thawed is accommodated, an electrode device disposed in a first space between the conductor partition wall and the thawing chamber partition wall, and a heat source disposed in a second space between the housing and the conductor partition wall. The electrode device includes a first electrode that radiates high-frequency waves into the thawing compartment, and a second electrode that is a ground electrode disposed on a side opposite to the thawing compartment with respect to the first electrode. The thawing compartment partition wall includes a first portion facing the first electrode and formed of a first member that allows the high frequency wave to pass therethrough, and a second portion formed of a second member that is located at a position farther from the electrode device than the first portion and has higher thermal conductivity than the first member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a defroster. [Background technology]

[0002] Patent Document 1 discloses a high-frequency thawing device that performs thawing by dielectric heating at high frequencies of several to several tens of MHz. The high-frequency thawing device of Patent Document 1 includes a pair of electrodes placed in a thawing chamber. A high-frequency electric field is generated between the pair of electrodes. An object to be thawed is placed between the pair of electrodes and thawed by the high-frequency electric field generated between the pair of electrodes.

[0003] Patent Document 2 also discloses a thawing machine. The thawing machine in Patent Document 2 includes an electrode device that emits high frequency waves to thaw food or other items to be thawed. This electrode device has a structure similar to a patch antenna (a patch-type electrode structure) and includes an electrode that emits high frequency waves and a ground electrode that is located on the opposite side of the electrode from the item to be thawed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-359064 [Patent Document 2] Patent Publication No. 2021-034231 Summary of the Invention

[0005] In Patent Document 2, the electrode device is disposed below the bottom surface of the thawing chamber where the object to be thawed is placed.

[0006] This arrangement can cause uneven surface temperatures of the items to be thawed. When a frozen item is placed in the thawing chamber, the cold air from the item causes the overall temperature of the chamber to drop. The item is then heated from within by the high-frequency radiation from the electrode device located below the bottom of the thawing chamber, causing it to thaw.

[0007] However, because the high frequency waves are radiated from below the bottom of the thawing chamber, the surface temperature on the top side of the thawing chamber, far from the electrode device, tends to be lower than on the bottom side of the thawing chamber, closer to the electrode device. In other words, the internal temperature of the item to be thawed increases due to high frequency dielectric heating, and the surface temperature of the item closer to the electrode device also increases due to the strong high frequency electric field. Meanwhile, the surface temperature on the side farther from the electrode device tends to remain low. In this way, a relatively large temperature distribution can occur on the surface of the item to be thawed. Such a temperature distribution on the surface of the item to be thawed is undesirable because it can cause uneven thawing of the item.

[0008] Therefore, it is desirable to prevent the occurrence of uneven surface temperature of the object to be thawed.

[0009] One aspect of the present disclosure is a thawing machine comprising: a housing; a conductive partition wall provided within the housing to form a high-frequency space for confining high-frequency waves therein; a thawing chamber partition wall provided within the conductive partition wall to form a thawing chamber for storing an object to be thawed therein; an electrode device disposed in a first space between the conductive partition wall and the thawing chamber partition wall; and a heat source disposed in a second space between the housing and the conductive partition wall, wherein the electrode device comprises a first electrode that radiates high-frequency waves into the thawing chamber and a second electrode that is a ground electrode and is disposed on the opposite side of the first electrode from the thawing chamber, and the thawing chamber partition wall comprises a first portion that faces the first electrode and is formed by a first member that allows the high-frequency waves to pass through, and a second portion that is located farther from the electrode device than the first portion and is formed by a second member that has higher thermal conductivity than the first member.

[0010] Further details will be described in the following embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an external view of the defrosting machine. [Figure 2] FIG. 2 is an external view of the defroster with the door omitted. [Figure 3]FIG. 3 is a plan view of the defroster. [Figure 4] Figure 4 shows the internal structure of the defroster. [Figure 5] FIG. 5 is a plan view of the electrode device. [Figure 6] FIG. 6 is a diagram showing a conventional electrode structure. [Figure 7] FIG. 7 is a diagram showing a patch-type electrode structure. DETAILED DESCRIPTION OF THE INVENTION

[0012] <1. Overview of the thawing machine>

[0013] (1) A thawing machine according to an embodiment may include a housing, a conductive partition wall provided within the housing to form a high-frequency space that confines high-frequency waves, a thawing chamber partition wall provided within the conductive partition wall to form a thawing chamber in which an object to be thawed is stored, an electrode device disposed in a first space between the conductive partition wall and the thawing chamber partition wall, and a heat source disposed in a second space between the housing and the conductive partition wall. The electrode device may include a first electrode that radiates high-frequency waves into the thawing chamber and a second electrode serving as a ground electrode that is disposed on the opposite side of the thawing chamber from the first electrode. The thawing chamber partition wall may include a first portion facing the first electrode and formed of a first member that allows the high-frequency waves to pass through, and a second portion that is located farther from the electrode device than the first portion and formed of a second member that has higher thermal conductivity than the first member. Because the second portion located farther from the electrode device has higher thermal conductivity, the second portion of the thawing chamber partition wall is heated by heat from the heat source, thereby suppressing temperature unevenness on the surface of the object to be thawed.

[0014] (2) The first member may be made of plastic.

[0015] (3) The second member may be made of metal.

[0016] (4) The heat source may include a circuit electrically connected to the electrode device.

[0017] (5) The circuit may include a high frequency amplifier connected to the electrode device.

[0018] (6) The thawing chamber partition may have a bottom surface, a top surface, and a side surface connecting the bottom surface and the top surface. The electrode device may be disposed below the bottom surface. The bottom surface may include the first portion. At least one of the top surface and the side surface may include the second portion.

[0019] (7) The heat source may include a high-frequency amplifier connected to the electrode device, and the high-frequency amplifier may be disposed below the electrode device in the second space.

[0020] <2. Examples of defrosting machines>

[0021] Hereinafter, the embodiments will be described in more detail with reference to the drawings.

[0022] 1 to 5 show a defroster 10 according to an embodiment. In the drawings, the X direction indicates the left-right direction (lateral direction) on a horizontal plane, the Y direction indicates the front-rear direction (depth direction) on the horizontal plane, and the Z direction indicates the up-down direction.

[0023] The thawing machine 10 has a thawing chamber 30A therein, and uses high frequency waves to thaw an object to be thawed (an object to be heated), such as food, placed in the thawing chamber 30A. The thawing machine 10 may use high frequency waves of, for example, 3 MHz to 300 MHz.

[0024] 1(A) and 1(B), the defrosting machine 10 includes a housing 20. A defrosting chamber 30A is provided inside the housing 20. The housing 20 includes a bottom surface 21, a top surface 22, a right side surface 23, a left side surface 24, a back surface 25 (third side surface), and a front surface 26 (fourth side surface).

[0025] The top surface 22 is located above the bottom surface 21. The side surface 23 connects the bottom surface 21 and the top surface 22 on one side in the left-right direction of the housing 20. The side surface 24 connects the bottom surface 21 and the top surface 22 on the other side in the left-right direction of the housing 20. The back surface 25 connects the bottom surface 21 and the top surface 22 on the back side of the housing 20. The front surface 26 connects the bottom surface 21 and the top surface 22 on the front side of the housing 20.

[0026] The housing 20 is connected to the ground of the alternating current voltage (for example, commercial AC voltage) that operates the defroster 10.

[0027] An operation unit 28 is provided on the front surface 26 of the housing 20. The operation unit 28 includes a display unit 28A and operation buttons 28B. A user of the defroster 10 operates the operation unit 28 to operate the defroster 10.

[0028] An opening 26A is formed on the front face 26 of the housing 20 for inserting and removing an object to be thawed into the thawing chamber 30A. A door portion 27 that can be opened and closed is provided on the front face 26 of the housing 20 (see FIG. 3 for opening and closing of the door portion 27). In FIGS. 1(A) and 1(B), the door portion 27 is closed, and the opening 26A is closed.

[0029] 2(A) and 2(B) show the door 27 of the thawing device 10 in an open state (the door 27 is not shown in FIGS. 2(A) and 2(B)). Opening the door 27 exposes an opening 26A in the front face 26 of the housing 20, allowing an object to be thawed 90, such as food, to be placed in and removed from the thawing chamber 30A through the opening 26A. The object to be thawed 90, such as food, is placed in the thawing chamber 30A for thawing.

[0030] As shown in Figure 2(A), the thawing chamber 30A is formed as an internal space of a thawing chamber partition 30 provided inside the housing 20. The thawing chamber partition 30 has a bottom surface 31, a top surface 32, a right side surface 33, a left side surface 34, and a rear surface (rear surface) 35. The thawing chamber partition 30 is not present in front of the thawing chamber 30A, and the front of the thawing chamber 30A is open via the aforementioned opening 26A, which serves as an entrance and exit for the object 90 to be thawed.

[0031] As shown in FIG. 2(B), the thawing machine 10 includes an electrode device 40 that serves as a high-frequency radiation source. The electrode device 40 of this embodiment is located outside the thawing chamber 30A. In FIG. 2(B), the electrode device 40 is, for example, disposed in the space within the housing 20 so as to be located below the bottom surface 31 of the thawing chamber partition 30. The electrode device 40 is disposed so as to face the thawing chamber 30A. More specifically, the electrode device 40 is disposed so as to face the bottom surface 31 of the thawing chamber 30A. The electrode device 40 radiates high-frequency waves into the thawing chamber 30A.

[0032] A conductive partition wall 50 is provided inside the housing 20. The conductive partition wall 50 forms a high-frequency space 50A that confines high-frequency waves inside. The conductive partition wall 50 is made of a conductor such as metal. It may be said that the conductive partition wall 50 is made of a material with high thermal conductivity such as metal. The conductive partition wall 50 is connected to the ground of a DC voltage that is obtained by AC / DC conversion of the AC voltage supplied to the thawing device 10 by a power supply circuit 65 described below.

[0033] The conductive partition wall 50 has a bottom surface 51, a top surface 52, a right side surface 53, a left side surface 54, and a back surface (rear surface) 55. The front side ends of the bottom surface 51, the top surface 52, the right side surface 53, and the left side surface 54 are connected to the front surface 26 of the housing 20 around the opening 26A.

[0034] An electrode device 40 that radiates high frequency waves to the thawing chamber 30A and a thawing chamber partition 30 that forms the thawing chamber 30A are disposed in the high frequency space 50A inside the conductive partition 50. In other words, the thawing chamber 30A and the electrode device 40 are surrounded by the conductive partition 50. The electrode device 40 is disposed in a space S10 (first space; electrode arrangement space) between the conductive partition 50 and the thawing chamber partition 30. The high frequency waves radiated from the electrode device 40 can reach the thawing chamber 30A, but do not leak out of the conductive partition 50 because the thawing chamber 30A is surrounded by the conductive partition 50.

[0035] A space S20 is formed between the housing 20 and the conductive partition wall 50. This space S20 serves as a space (second space) in which a circuit 60 for operating the defroster 10 and the like are arranged.

[0036] 2(B) and 3, the circuit 60 includes, for example, a power supply circuit 65, a high-frequency circuit 66, a control circuit 67, and other circuits 68. The power supply circuit 65 converts an AC voltage (for example, a commercial AC voltage) into a DC voltage. This DC voltage is supplied to the high-frequency circuit 66, the control circuit 67, and the other circuits 68 as a power supply voltage for those circuits.

[0037] The high-frequency circuit 66 includes a high-frequency amplifier that amplifies the high-frequency wave generated by the high-frequency generator. The high-frequency amplifier is connected to the electrode device 40. The amplified high-frequency wave is supplied to the electrode device 40 via a power supply line. The electrode device 40 radiates the high-frequency wave as an electromagnetic wave.

[0038] The control circuit 67 controls the operation of the high frequency circuit 66 and other parts of the defrosting machine 10. The control circuit 67 is connected to the operation unit 28, and can operate in response to operations on the operation unit 28.

[0039] The power supply circuit 65, the high-frequency circuit 66, the control circuit 67, and the other circuits 68 are arranged in the space S20. For example, as shown in FIG. 3, the power supply circuit 65 is arranged behind the back surface 55 of the conductive partition wall 50. As shown in FIGS. 2(B) and 3, the control circuit 67 is arranged laterally on the side surface 54 of the conductive partition wall 50. As shown in FIG. 2(B), the other circuits 68 are arranged above the top surface 52 of the conductive partition wall 50. The space S20 in which the circuits 65, 66, 67, and 68 are arranged is a space outside the conductive partition wall 50, and therefore the circuits 65, 66, 67, and 68 can be prevented from being affected by high-frequency waves radiated from the electrode device 40.

[0040] Circuits 65, 66, 67, and 68 function as heat sources because they consume power during operation and generate heat. As described below, circuits 65, 66, 67, and 68 function as heat sources to prevent uneven temperature distribution in thawing chamber 30A. Among circuits 65, 66, 67, and 68, the amplifier included in high-frequency circuit 66 generates a relatively large amount of heat, making it particularly suitable as a heat source.

[0041] 4 and 5, the electrode device 40 includes a first electrode 41 that emits high-frequency waves and a second electrode that is a ground electrode 42 that is located on the opposite side of the electrode 41 from the object to be thawed 90. The electrode device 40 emits high-frequency waves for thawing. The first electrode 41 that emits high-frequency waves is located so as to face the bottom surface 31 of the thawing chamber partition 30.

[0042] Here, thawing is sometimes performed using the thawing function of a microwave oven using microwave heating. The microwave frequency in a microwave oven is generally 2450 MHz. However, thawing using microwave heating is prone to surface burning due to the short wavelength of the microwaves.

[0043] A good thawing method is the high-frequency dielectric heating method, which uses high-frequency waves of 3 MHz to 300 MHz. This high-frequency dielectric heating method has a longer wavelength than microwave heating, so it can heat the food from the inside.

[0044] 6(A) and 6(B) schematically show a pair of electrodes 101, 102 for conventional high-frequency dielectric heating, such as that disclosed in Patent Document 1. The pair of electrodes 101, 102 includes an upper electrode 101 and a lower electrode 102. A high-frequency generator 103 connected to the pair of electrodes 101, 102 generates a high-frequency electric field 110 between the pair of electrodes 101, 102. An object to be thawed (dielectric material) placed between the pair of electrodes 101, 102 is thawed by induction heating using the high-frequency electric field 110.

[0045] 6(A) and (B), the efficiency of dielectric heating is low. This is because the range of high-frequency energy emission is not limited to the area between the pair of electrodes 101 and 102, but extends to the surrounding area. Furthermore, in the electrode structure shown in FIGS. 6(A) and (B), if the electrodes 101 and 102 are made smaller, impedance matching becomes difficult, which hinders high-frequency power supply.

[0046] The electrode structure shown in Figures 7(A) and (B) is more advantageous than the electrode structure shown in Figures 6(A) and (B). The electrode structure shown in Figures 7(A) and (B) has a structure similar to a patch antenna. That is, the electrode structure shown in Figures 7(A) and (B) includes a first electrode 121 that radiates high frequency waves and a ground electrode 122 (second electrode) that is arranged on the opposite side of the first electrode 121 from the object to be thawed 90. The electrode structure shown in Figures 7(A) and (B) is called a patch-type electrode structure.

[0047] In the case of the patch-type electrode structure, the emission range of high-frequency energy is substantially limited to the range directly above the first electrode 121, which is opposite the ground electrode 122. Therefore, the object to be thawed 90 placed directly above the electrode 121 can be efficiently heated.

[0048] 6(A) and 6(B), high-frequency energy is emitted by applying a high voltage to the pair of electrodes 101, 102 and accumulating charge between the pair of electrodes 101, 102. The distance between the pair of electrodes 101, 102, on which the object to be thawed is placed, must be maintained at a distance equal to or greater than the thickness of the object to be thawed. Storing charge between the pair of electrodes 101, 102, which is far apart, requires a large amount of power, which reduces the efficiency of dielectric heating.

[0049] 7(A) and 7(B), the emission range of high-frequency energy is limited to the range directly above electrode 121, which is opposite ground electrode 122. Therefore, high-frequency energy can be emitted by the current flowing through electrode 121, making it possible to efficiently heat an object to be thawed placed directly above electrode 121.

[0050] However, like a patch antenna, a patch-type electrode structure must have a size corresponding to the high-frequency wavelength, and therefore is large. That is, in the case of a square-pattern patch antenna, the length of one side is set to, for example, 1 / 2 the wavelength. Therefore, when the electrode 121 is square as shown in FIG. 7(A), the length of one side of the electrode 121 is also set to, for example, 1 / 2 the wavelength. In this case, if a high frequency of 40 MHz is to be used, the length of one side of the electrode 121 will be approximately 3.7 m.

[0051] Therefore, when miniaturization is required, it is preferable that the electrode device 40 has a structure similar to the patch-type electrode structure, but the first electrode 41 that radiates high frequency waves has a shape as shown in FIG. 5. The shape of the first electrode 41 shown in FIG. 5 is spiral. The spiral shape of the electrode 41 that radiates high frequency waves allows the electrode 41 to have a relatively long line length. Therefore, even if the line length of the electrode 41 is increased to use high frequency waves with a long wavelength, the electrode 41 can be made small. Moreover, since the electrode device 40 shown in FIG. 5 has a structure similar to the patch-type electrode structure, it has better high frequency energy emission efficiency and can heat more efficiently than the electrode structures shown in FIGS. 6(A) and (B).

[0052] 5 is miniaturized, it is possible to miniaturize the thawing machine 10. The thawing machine 10 of the embodiment may be approximately the same size as a home microwave oven, for example.

[0053] A high frequency is supplied to the electrode device 40 from a high frequency generator 62 provided in a high frequency circuit 66 via a power supply line 61. The power supply line 61 is formed of, for example, a coaxial cable. The inner conductor (high frequency transmission line) of the coaxial cable is connected to the first electrode 41. The outer conductor (ground) of the coaxial cable is connected to the ground electrode 42 (second electrode).

[0054] The electrode device 40 includes a substrate 43 having a first surface 43A and a second surface 43B. The first surface 43A faces the thawing chamber 30A and faces upward in FIG. 4. The second surface 43B is the surface opposite the first surface 43A and faces downward in FIG. 4.

[0055] The first electrode 41 is disposed on the first surface 43A and faces the bottom surface 31 of the thawing chamber 30A. The first electrode 41 irradiates high-frequency waves to the object 90 to be thawed in the thawing chamber 30A. The irradiated high-frequency waves are introduced into the thawing chamber 30A through the bottom surface 31 and heat the object 90 to be thawed.

[0056] The first electrode 41 is configured as a line-shaped electrode, rather than a rectangular planar electrode like the electrodes 121 and 122 shown in FIGS. 6(A) and 6(B). A line-shaped electrode is a long, thin electrode. The first electrode 41 may be configured, for example, of a line-shaped conductor such as a conductive cable. The conductive cable constituting the first electrode 41 may be a solid-wire cable or a twisted-wire cable. In the case of a twisted-wire cable, the surface area of ​​the conductor is increased, which increases the high-frequency transmission efficiency due to the skin effect and reduces the high-frequency transmission loss. Therefore, the object to be thawed 90 can be heated more efficiently.

[0057] Furthermore, the first electrode 41 may be formed of a conductive plate processed into a spiral shape. The spiral shape is formed by, for example, cutting or pressing. If the electrode 41 is processed into a spiral shape in advance, a winding process for forming the spiral shape is not required.

[0058] The first electrode 41 may be formed by stacking multiple conductive plates. That is, the first electrode 41 may have a laminated structure including multiple conductive layers. Because each of the multiple conductive layers has a surface, the first electrode 41 with a laminated structure has a larger surface area than an electrode made of a single material. The larger surface area increases the high-frequency transmission efficiency due to the skin effect, and reduces the high-frequency transmission loss. Therefore, the object 90 to be thawed can be heated more efficiently.

[0059] The first electrode 41 has a line length that depends on the frequency of the radiated radio frequency. The frequency of the radio frequency generated by the radio frequency generator 62 is preferably within the range of 3 MHz to 300 MHz. The line length that depends on the radio frequency frequency is, for example, 4 times, 2 times, 1 time, 1 / 2 times, 1 / 4 times, 1 / 8 times, 5 / 8 times, or 3 / 8 times the wavelength λ of the radio frequency.

[0060] Because the wavelength λ of the radio frequency is long, the line length of the first electrode 41, which is determined depending on the frequency of the radio frequency, tends to be long. For example, when the frequency of the radio frequency is 40 MHz, the wavelength λ is 7.5 m. When the line length of the elongated first electrode 41 is set to 1 / 2 of the wavelength λ, the line length becomes approximately 3.7 m.

[0061] The first electrode 41, which has a relatively long line length, is arranged on the first surface 43A with the line-like conductor wound in a spiral shape. Note that the winding does not have to be circular, and may be polygonal. Here, the spiral is, for example, a two-dimensional curve that moves away from the center as it turns. That is, in the embodiment, the spiral shape is a two-dimensional spiral shape in which the line-like conductor is wound in a two-dimensional plane.

[0062] As shown in FIG. 5 , the electrode 41 has one longitudinal end (first end) 41A and the other longitudinal end (second end) 41B. The length from the first end 41A to the second end 41B is the line length of the electrode 41. The first electrode 41, which is formed continuously from the first end 41A to the second end, is wound in a circular shape on the plane of the first surface 43A around the second end 41B, with the first end 41A positioned at the outermost periphery of the spiral shape. Therefore, even if the electrode 41 has a line length of, for example, 3.7 m, the spiral diameter can be set to approximately 10-15 cm to several tens of cm, allowing the electrode device 40 to be miniaturized. As a result, even when a high frequency wave with a long wavelength is used, the mounting area of ​​the electrode device 40 can be reduced, and the electrode device 40 can be placed in a relatively small housing 20.

[0063] The line length and feeding point 41A of the first electrode 41 are preferably set to satisfy the boundary conditions for the electrode device 40 to have an optimal impedance. When the electrode device 40 has an optimal impedance, impedance matching becomes easy and high frequency power can be fed efficiently.

[0064] The ground electrode 42 (second electrode) is composed of a conductive pattern formed on the second surface 43B. The ground electrode 42 is located behind the electrode 41, i.e., on the opposite side of the electrode 41 from the object to be thawed 90. The ground electrode 42 reflects the electric field energy emitted in all directions from the electrode 41 toward the object to be thawed 90. By providing the ground electrode 42 behind the electrode 41, the electric field energy can be efficiently irradiated onto the object to be heated 90.

[0065] In addition, the ground electrode 42 provided behind the electrode 41 also serves to optimize the impedance of the electrode device 40 .

[0066] A dielectric member such as a substrate 43 may be present between the electrode 41 and the ground electrode 42, or the substrate 43 may be omitted and an air layer may be present instead.

[0067] As shown in FIG. 4, the thawing chamber partition 30 includes a first portion 31 and second portions 32, 33, 34, and 35.

[0068] The first portion 31 is a portion of the thawing chamber partition 30 that faces the first electrode 41 of the electrode device 40. The first portion 31 allows the high frequency waves radiated from the electrode device 40 to pass through to the thawing chamber 30A. In FIG. 4 , the first portion 31 is, for example, the bottom surface 31 of the thawing chamber partition 30.

[0069] The second portions 32, 33, 34, and 35 are portions of the thawing chamber partition 30 that are located farther from the electrode device 40 than the first portion 31. In Figure 4, the second portions 32, 33, and 34 are, for example, the top surface 32, the side surfaces 33 and 34, and the back surface 35 of the thawing chamber partition 30.

[0070] The first portion 31 and the second portions 32, 33, 34 are formed of different materials. That is, the defrosting chamber partition 30 is made of different materials depending on the portion.

[0071] The first member constituting the first portion 31 is made of a material that allows high frequency waves to pass through so that the electric current radiated from the first electrode 41 can be introduced into the thawing chamber 30A. The first member constituting the first portion 31 is made of an electromagnetic wave-transmitting material such as plastic. Electromagnetic wave-transmitting materials such as plastic have low thermal conductivity.

[0072] The second members constituting the second portions 32, 33, 34, and 35 are made of a material with higher thermal conductivity than the first members constituting the first portion 31. The second members are made of, for example, metal. Metal has higher thermal conductivity than plastic. Note that the second portions 32, 33, 34, and 35 are preferably not connected to ground, but may be connected to ground.

[0073] The thawing chamber partition 30 has the first portion 31 and the second portions 32, 33, 34, and 35, which reduces the temperature distribution in the thawing chamber 30A, thereby reducing the surface temperature distribution of the object to be thawed 90. The reason why the temperature distribution can be reduced is as follows.

[0074] When a frozen object to be thawed 90 is placed in the thawing chamber 30A, the cold air from the object to be thawed 90 causes the temperature of the thawing chamber 30A to drop overall. In this lowered temperature state, high frequency waves are emitted from the electrode device 40 on the bottom surface 31 (first portion 31) side of the thawing chamber 30A, and thawing begins. Because the bottom surface 31 of the thawing chamber partition 30 is the first portion 31 that allows high frequency waves to pass through, the high frequency waves are introduced into the thawing chamber 30A without any problems.

[0075] Here, if we only consider the passage of high frequency waves through thawing chamber partition 30, it is conceivable to form all of surfaces 31, 32, 33, 34, 35 of thawing chamber partition 30 from a material (e.g., plastic) that allows high frequency waves to pass through. However, in this case, the temperature distribution in thawing chamber 30A becomes large, and the surface temperature distribution of object 90 to be thawed also becomes large, making uneven thawing more likely to occur.

[0076] That is, when a frozen object to be thawed 90 is placed in the thawing chamber 30A, the overall temperature of the thawing chamber 30A drops due to the cold air from the object to be thawed 90. If the entire thawing chamber partition 30 is made of a material with low thermal conductivity, such as plastic, the thawing chamber 30A functions as a refrigerator, making it easier to maintain a low temperature.

[0077] When the temperature of the entire thawing chamber 30A is maintained low and high frequency waves are radiated from below the bottom surface 31 of the thawing chamber 30A, as shown in Figure 7(B), the surface temperature T3 of the object 90 to be thawed on the top surface 32 side farther from the electrode device 40 is likely to be lower than the surface temperature T1 on the bottom surface 31 side closer to the electrode device 40. In other words, the temperature (internal temperature T4 and surface temperature T1) inside the object to be thawed and on the side closer to the electrode device 40 is high due to the strong high frequency electric field, while the temperature (surface temperatures T2, T3) on the side farther from the electrode device 40 is likely to remain low. For example, in Figure 7(B), the internal temperature T4 is -2°C, the surface temperature T1 near the electrode device 40 is -4°C, while the surface temperature T2 is -5°C and the surface temperature T3 is -8°C, meaning that the surface temperature decreases the further away from the electrode device 40. In this way, if all of the surfaces 31, 32, 33, 34, and 35 of the thawing chamber partition 30 are made of a material that allows high-frequency waves to pass through, such as plastic, the thawing chamber 30A can be thermally insulated, but the temperature distribution in the thawing chamber 30A may become large. As a result, the surface temperature of the object 90 to be thawed becomes uneven, making it more likely that the thawing will be uneven.

[0078] 4, by providing second portions 32, 33, 34, and 35 with high thermal conductivity in thawing chamber partition 30, heat from outside thawing chamber 30A can be introduced into thawing chamber 30A through second portions 32, 33, 34, and 35, thereby suppressing temperature unevenness in thawing chamber 30A. This also suppresses unevenness in the surface temperature of object 90 to be thawed.

[0079] In Figure 4, the dotted arrows indicate radiant heat being transferred to thawing chamber 30A. As indicated by the dotted arrows in Figure 4, heat from a heat source outside thawing chamber 30A is transferred into thawing chamber 30A from top surface 32, side surfaces 33, 34, and rear surface 35, which are the second parts with high thermal conductivity. This makes it easier for the surface temperatures near top surface 32, side surfaces 33, 34, and rear surface 35 to rise.

[0080] The top surface 32, sides 33, 34, and back surface 35 are farther from the electrode device 40 than the bottom surface 31 on which the electrode device 40 is located, so the surface temperature near these surfaces 32, 33, 34, and 35 is likely to drop, but because they have high thermal conductivity, heat from a heat source outside the thawing chamber 30A is transferred, preventing the surface temperature from dropping.

[0081] On the other hand, the bottom surface 31, which is the first portion 31 closer to the electrode device 40, has lower thermal conductivity than the second portions 32, 33, 34, and 35. Therefore, heat from a heat source outside the thawing chamber 30A is less likely to be transmitted through the bottom surface 31. Therefore, the area near the bottom surface 31 is hardly heated by heat from a heat source outside the thawing chamber 30A. Thus, heat from a heat source outside the thawing chamber 30A hardly heats the first portion 31 closer to the electrode device 40, but heats the second portions 32, 33, 34, and 35 farther from the electrode device 40. Therefore, the temperatures near the surfaces 32, 33, 34, and 35 heated by heat from a heat source outside the thawing chamber 30A approach the surface temperature near the bottom surface 31 heated by the high-frequency waves emitted from the electrode device 40, and the surface temperature distribution is reduced. As a result, uneven thawing is suppressed.

[0082] Furthermore, even if the second portions 32, 33, 34, and 35 are made of a conductor such as metal to increase thermal conductivity, this does not pose a problem because the second portions 32, 33, 34, and 35 are not the portions that introduce high frequency waves from the electrode device 40 into the thawing chamber 30A.

[0083] As an example of a heat source outside the thawing chamber 30A, the circuit 60 is used. The circuit 60 generates heat during operation and can be used as a heat source. The heat generated by the circuit 60 gradually increases as the operation of the circuit 60 progresses, but does not reach very high temperatures and is relatively mild. For this reason, the circuit 60 as a heat source for heating the thawing chamber 30A is suitable for gently warming the thawing chamber 30A rather than suddenly heating it to a high temperature. A rise in the surface temperature exceeding the internal temperature causes dripping, which can cause the food to lose its flavor.

[0084] The heat generated from the circuit 60 passes through the conductive partition wall 50, reaches the thawing chamber partition wall 30, and heats the thawing chamber 30A. Because the conductive partition wall 50 is made of a material with high thermal conductivity, such as metal, the heat generated from the circuit 60, which is a heat source outside the conductive partition wall 50, can be efficiently conducted to the thawing chamber 30A inside the conductive partition wall 50.

[0085] The circuit 60 of this embodiment is disposed around the thawing chamber 30A, which is suitable for balanced heating of the thawing chamber 30A. In particular, it is preferable for the high-frequency circuit 66 including the high-frequency amplifier to be disposed below the thawing chamber 30A (below the electrode device 40). High-frequency amplifiers generate relatively large amounts of heat and are therefore particularly suitable as heat sources. When the high-frequency circuit 66 including the high-frequency amplifier that generates large amounts of heat is disposed below the thawing chamber 30A, the heat generated by the high-frequency circuit 66 including the high-frequency amplifier is easily transferred upward, as shown in FIG. 4 . This heat heats the entire conductive partition wall 50, which in turn heats the second portions 32, 33, 34, and 35 of the thawing chamber 30A. Even if the high-frequency circuit 66 that generates large amounts of heat is disposed below the thawing chamber 30A, this is not a problem because the electrode device 40 is disposed directly below the bottom surface 31 of the thawing chamber 30A and the bottom surface 31 itself has low thermal conductivity.

[0086] The present invention is not limited to the above-described embodiment, and various modifications are possible. [Explanation of symbols]

[0087] 10: Thawing machine 20: Housing 21: Bottom 22: Top 23: Right side 24: Left side 25: Back 26:Front 26A:Aperture 27: Door section 28 :Operation section 28A: Display section 28B: Operation button 30: Thawing chamber bulkhead 30A: Thawing chamber 31: Bottom (first part) 32: Top (second part) 33: Right side (second part) 34: Left side (second part) 34: Side (second part) 35: Back (second part) 40: Electrode device 41: 1st electrode 41A: 1st end 41B: 2nd end 42: Second electrode (ground electrode) 43: Substrate 43A: 1st page 43B: 2nd side 50: Conductor barrier 50A: High frequency space 51: Bottom 52: Top 53: Right side 54: Left side 55: Back 60: Circuit 61:Power line 62: High frequency generator 65: Power supply circuit 66: High frequency circuits 67: Control circuit 68:Other circuits 90:Thawing object 101: Upper electrode 102: Lower electrode 103: High frequency generator 110: High frequency electric field 121: 1st electrode 122: Ground electrode S10: Space S20: Space T1 :Temperature T2 :Temperature T3 :Temperature

Claims

1. The housing and a conductive partition wall provided in the housing to form a high-frequency space for confining high-frequency waves therein; a thawing chamber partition provided within the conductive partition to form a thawing chamber in which an object to be thawed is accommodated; an electrode device disposed in a first space between the conductive partition wall and the thawing chamber partition wall; a heat source disposed in a second space between the housing and the conductive partition wall; Equipped with the electrode device includes a first electrode that radiates the high frequency wave into the thawing chamber, and a second electrode that is a ground electrode and is disposed on the opposite side of the thawing chamber from the first electrode, The thawing chamber partition is a first portion formed by a first member that faces the first electrode and allows the high frequency wave to pass; a second portion located farther from the electrode device than the first portion and formed of a second member having higher thermal conductivity than the first member; Equipped with Thawing machine.

2. The first member is made of plastic. The defroster according to claim 1.

3. The second member is made of metal. The defroster according to claim 1.

4. the heat source includes a circuit electrically connected to the electrode device; The defroster according to claim 1.

5. the circuit includes a radio frequency amplifier connected to the electrode device; The defroster according to claim 4.

6. The thawing chamber partition is The bottom and The top and a side surface connecting the bottom surface and the top surface; Equipped with the electrode device is disposed below the bottom surface; the bottom surface includes the first portion; At least one of the top surface and the side surface includes the second portion. The defroster according to claim 1.

7. the heat source includes a radio frequency amplifier connected to the electrode device; the high-frequency amplifier is disposed below the electrode device in the second space; The defroster according to claim 6.

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