Heating cooker

Abstract

The invention provides a heating cooker capable of efficiently heating various cooked objects. The disclosed heating cooker is provided with: a container unit that accommodates an object to be cooked; an antenna that radiates a high frequency supplied from a high-frequency circuit that outputs the high frequency into the container unit as an electromagnetic wave for heating the object to be cooked; and a placement surface on which the object to be cooked is placed, the container unit being configured so as to form a resonant cavity that resonates with the electromagnetic wave radiated from the antenna, and the heating cooker being configured so as to be able to change a first distance between the antenna and the object to be cooked placed on the placement surface.

Description

Technical Field

[0001] The present disclosure relates to a heating cooker. This application claims priority based on Japanese Application No. 2022-108222 filed on July 5, 2022, and all the contents described in the above Japanese Application are cited. Background Art

[0002] As a heating cooker, there is a device that uses electromagnetic waves radiated from an antenna to heat the food to be cooked. Patent document 1 discloses that the cavity in which the object to be electromagnetically heated is arranged is a resonant cavity that resonates at a frequency in the UHF or microwave range. Through the resonance of the cavity, the energy loss of the electromagnetic wave can be suppressed, thereby efficiently heating the object.

[0003] Patent document 2 discloses a split type microwave oven having a microwave heating resonant cavity. The split type microwave oven of Patent document 2 includes a loading plate. The loading plate is located in the microwave heating resonant cavity. The object to be heated is placed on the loading plate. In Patent document 1, an electromagnetic wave guiding member for guiding microwaves into the microwave heating resonant cavity is arranged directly below the loading plate.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-238617

[0007] Patent Document 2: Japanese Patent Application No. 2019-509585 Summary of the invention

[0008] In Patent Document 2, when a plurality of housing units constituting a microwave heating resonant cavity are coupled, the positional relationship between an electromagnetic wave guide member serving as a radiation source of electromagnetic waves and a mounting plate is fixed and does not change.

[0009] The inventors of the present invention have found through experiments that in order to efficiently heat the food to be cooked, it is best to change the distance between the antenna radiating electromagnetic waves and the food to be cooked. For example, in the case of a larger food to be cooked, the distance between the antenna and the food to be cooked is preferably closer, but in the case of a smaller food to be cooked, the distance between the antenna and the food to be cooked is preferably larger.

[0010] Furthermore, the optimum antenna-to-food distance for efficient heating often becomes smaller as heating proceeds.

[0011] Therefore, in order to efficiently heat various types of food to be cooked, it is desired to be able to adjust the distance between the antenna and the food to be cooked.

[0012] One aspect of the present disclosure is a heating cooker. The disclosed heating cooker comprises: a container unit for storing food to be cooked; an antenna for radiating high frequency supplied from a high frequency circuit for outputting high frequency into the container unit as electromagnetic waves for heating the food to be cooked; and a placing surface for placing the food to be cooked, the container unit being configured to form a resonant cavity that resonates with the electromagnetic waves radiated from the antenna, and the heating cooker being configured to be able to change a first distance between the antenna and the food to be cooked placed on the placing surface.

[0013] More detailed contents will be described as embodiments described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a cross-sectional view of the internal structure of a heating cooker.

[0015] Figure 2 It is a schematic diagram of separated and joined container units.

[0016] Figure 3 It is an exploded sectional view of the container unit.

[0017] Figure 4 This is a schematic diagram of the second segment unit.

[0018] Figure 5 This is a circuit diagram of a heating cooker.

[0019] Figure 6 This is a flowchart of the operation of the heating cooker.

[0020] Figure 7 It is a plan view showing the horizontal movement of the second split body unit.

[0021] Figure 8 is a schematic diagram of a telescopic container unit.

[0022] Fig. 9 It is a schematic diagram of a container unit in which the height of the placement surface can be adjusted.

[0023] Fig.10 is a cross-sectional view showing radiation of electromagnetic waves.

[0024] Fig.11 yes Fig.10 XI-XI line cross-sectional view.

[0025] Fig.12 This is a diagram for explaining the horizontal movement of the lower kettle.

[0026] Fig.13 This is a diagram showing another example of the movement of the placement surface.

[0027] Fig.14 is a graph showing the experimental results. DETAILED DESCRIPTION

[0028] <1. Overview of the heating cooker>

[0029] (1) A heating cooker according to an embodiment includes: a container unit for storing a food to be cooked; an antenna for radiating the high frequency supplied from a high frequency circuit for outputting a high frequency into the container unit as an electromagnetic wave for heating the food to be cooked; and a placing surface for placing the food to be cooked, wherein the container unit is configured to form a resonant cavity that resonates with the electromagnetic wave radiated from the antenna, and the heating cooker is configured to be able to change a first distance between the antenna and the food to be cooked placed on the placing surface. According to this configuration, the distance between the antenna and the food to be cooked can be adjusted, and various foods to be cooked can be efficiently heated. To change the first distance, for example, the antenna can be fixed in position and the placing surface can be moved. For example, the placing surface is preferably configured to be movable within the first unit, so that the first distance can be changed. In addition, to change the first distance, the placing surface can be fixed in position and the antenna can be moved. In addition, both the antenna and the placing surface can be movable.

[0030] (2) Preferably, a cooking food storage space for storing the cooking food placed on the placement surface is arranged in the container unit so as to exist between the antenna and the placement surface.

[0031] (3) Preferably, the antenna is arranged above the placement surface in the container unit, and the placement surface is provided to be movable in a vertical direction in the container unit.

[0032] (4) Preferably, the cooking device further includes a controller that monitors the operating state of the high frequency circuit during the radiation of the electromagnetic wave and controls the first distance according to the operating state. The controller 40 can control at least one of the movement of the placement surface and the movement of the antenna.

[0033] (5) Preferably, the placing surface is in a first position as an initial position before the electromagnetic wave is radiated, and the controller is configured to move the placing surface from the first position to a second position according to the operating state during the electromagnetic wave radiation, the second position being a position where the first distance is smaller than when the placing surface is in the first position. The controller may also be configured to move the placing surface not only to the second position but also to a third position where the first distance is larger than when the placing surface is in the first position.

[0034] (6) Preferably, the placement surface is provided to be movable within the container unit so as to change a second distance between the placement surface and the antenna, and the first position is a position where the second distance is maximized.

[0035] (7) Preferably, the container unit has a surplus space between the cooking storage space and the antenna in which the cooking is not present when the placing surface is in the first position, and the surplus space is a space in which the cooking can be present when the placing surface is moved to the second position.

[0036] (8) Preferably, the container unit is configured such that the volume of the container unit is variable. The volume here refers to the volume inside the container unit, which is equal to the volume of the chamber. By changing the volume of the container unit, the resonant frequency can be adjusted. In addition, the volume of the container unit may not be variable, and the volume may be fixed.

[0037] (9) Preferably, the device further comprises a controller for monitoring the operating state of the high frequency circuit during the radiation of the electromagnetic wave and adjusting the volume according to the operating state. In this case, the volume is appropriately adjusted according to the reflected wave.

[0038] (10) Preferably, the cooking device further includes a controller that monitors an operating state of the high-frequency circuit during radiation of the electromagnetic wave, and controls the size of the first distance and adjusts the volume according to the operating state.

[0039] In addition, it is preferred that the container unit includes a plurality of split bodies and is configured to be changeable to a first state and a second state, the first state being a state in which the plurality of split bodies are joined so that the interior of the container unit becomes a closed space, and the second state being a state in which an opening for placing the food to be cooked in the container unit appears by at least any one of the plurality of split bodies moving from the first state, the plurality of split bodies including a first split body provided with the antenna and a second split body provided with the placement surface, and in order to change the state of the container unit between the first state and the second state, the second split body is configured to move in a direction orthogonal to the placement surface. In this case, the second split body, which is not the first split body provided with the antenna, can move in a direction orthogonal to the placement surface.

[0040] In addition, it is preferred that the container unit is configured to form a resonant cavity that resonates with the electromagnetic wave radiated from the antenna in the first state in which the plurality of split bodies are joined to accommodate the food. In this case, the container unit that forms the resonant cavity is a split structure composed of a plurality of split bodies, and forms a resonant cavity in the first state in which the plurality of split bodies are joined. By making the container unit a split structure, the split bodies of the container can each play an appropriate role.

[0041] Preferably, each of the plurality of split bodies has a partial chamber inside, and the resonant cavity is formed as a space in which the partial chambers of each of the plurality of split bodies are connected in the first state. In this case, the chamber is composed of a combination of a plurality of partial chambers. By making the chamber a split structure, the plurality of partial chambers can each play an appropriate role.

[0042] Preferably, at least one of the partial cavities included in the plurality of divided bodies is provided with a placement surface on which the food to be cooked is placed, and in order to change the state of the container unit between the first state and the second state, at least one of the plurality of divided bodies is configured to move in a direction perpendicular to the placement surface. In this case, the moving direction of the moving divided body is a direction perpendicular to the placement surface.

[0043] Furthermore, it is preferable that the first divided body is provided at a fixed position in the cooking device. By providing the first divided body provided with the antenna at a fixed position, it is possible to avoid movement of the first divided body which may increase the fluctuation of the resonance frequency.

[0044] In addition, preferably, the container unit has an opening for placing the cooked food into the container unit, the radiation of the electromagnetic wave is performed when the opening is closed, and the cooked food storage space is a space of a size corresponding to the maximum size of the cooked food that can be placed into the container unit from the opening and with the opening closed.

[0045] In addition, the cooking storage space for placing the cooking object may not exist between the antenna and the placement surface. For example, when viewed from the placement surface, the antenna may be disposed on the side opposite to the side where the cooking storage space is located.

[0046] <2. Example of a heating cooker>

[0047] Hereinafter, an example of the heating cooker 10 according to the embodiment will be described with reference to the drawings. Figure 1 The internal cross-sectional structure of the heating cooker 10 according to the embodiment is shown. Figure 1 In the figure, the left side is the front side of the heating cooker 10, and the right side is the back side of the heating cooker 10. Figure 1 In the same figure as in the other figures, the X direction indicates the left-right direction of the cooking device 10, the Y direction indicates the front-back direction of the cooking device 10, and the Z direction indicates the height direction of the cooking device 10. The XY plane is a horizontal plane.

[0048] The heating cooker 10 includes a container unit 20 in which a food to be cooked is placed. The heating cooker 10 heats the food to be cooked stored in the container unit 20. The food to be cooked is, for example, frozen meat, frozen cake, or rice soaked in water for cooking. Cooking here is a concept including merely heating the food to be cooked.

[0049] The container unit 20 includes a plurality of partitions 210 and 220. As an example, Figure 1 The container unit 20 includes a first divided body 210 and a second divided body 220. The container unit 20 may include three or more divided bodies. Figure 1 The first divided body 210 shown may also be referred to as an upper container 210 or an upper pot 210 . Figure 2 The second divided body 220 shown may also be referred to as a lower container 220 or a lower kettle 220 .

[0050] The plurality of divided bodies 210 and 220 are each formed of a conductor, such as stainless steel, aluminum, or copper.

[0051] The container unit 20 includes an inner container 250 disposed therein. The inner container 250 is, for example, a glass container or pottery. The material constituting the inner container 250 is preferably an insulator, but may also be a conductor. In addition, the inner container 250 may also be a heating element. In this case, the heat generated by the inner container 250 may also assist in heating the food to be cooked.

[0052] The inner container 250 includes a bottom 250B forming a loading surface 250A and a side wall 250C formed by rising upward from the periphery of the bottom 250B. The loading surface 250A here is a horizontal plane (XY plane). The bottom 250B is circular, for example, when viewed from above. A snap-fitting portion 250D extending in the radially outward direction of the inner container 250 is formed on the upper portion of the side wall 250C. The snap-fitting portion 250D snaps with the snap-fitting portion 224 in order to position the inner container 250 in the container unit 20. The inner container 250 can be configured to be movable in the container unit 20. As an example, the inner container 250 is movable in the up-down direction (Z direction) in the container unit 20. In the case where the inner container 250 is formed of an insulator such as glass, the container 250 can include a conductor such as metal. The conductor provided in the container 250 is, for example, stainless steel (SUS). The conductor included in the container 250 can be arranged, for example, on the lower side of the bottom 250B. The conductor can be arranged on substantially the entire surface of the bottom 205B. The conductor arranged on the lower side of the bottom 205B can be integrally mounted on the container 250, or can be arranged on the lower side of the bottom 205B in a manner that can be separated from the container 250. The conductor moves in the vertical direction together with the container 250 in the container unit 20.

[0053] The container unit 20 has a split structure formed by combining a plurality of split bodies 210 and 220. The plurality of split bodies 210 and 220 can be joined and separated from each other. Figure 1 In the first state (closed state) in which the containers 20 are connected to each other, a single cavity 200 is formed inside the container unit 20. The cavity 200 functions as a cooking chamber for storing food to be cooked. In the first state, the cavity 200 is a closed space.

[0054] The container unit 20 can also be in a second state as an open state. The second state is obtained by at least one of the plurality of split bodies moving from the first state. In the second state, an opening for placing food to be cooked in the container unit 20 appears. The second state is, for example, a state in which the first split body 210 and the second split body 220 are separated. In the second state, the chamber 200 is open to the outside. As an example, the first split body 210 and the second split body 220 are separated in the up-down direction (Z direction). In order to separate or join, either or both of the first split body 210 and the second split body 220 can move, but it is preferred that the first split body 210 does not move and the second split body 220 moves. In addition, the second state may also be a state in which, in a state in which the first split body 210 and a part of the second split body 22 are combined or contacted, at least one of the two split bodies 210 and 220 moves (the movement here is, for example, rotation or sliding), so that an opening for placing food to be cooked appears.

[0055] The cooking device 10 includes a second split body unit 300 having a second split body 220. The second split body 220 is configured to be able to change its volume in the second split body unit 300. In addition, the internal container 250 is movably provided in the second split body unit 300. The second split body unit 300 is configured by installing the second split body 220 in a unit casing 310. A part of the adjustment mechanism 80 described later is provided in the unit casing 310.

[0056] The adjustment mechanism 80 included in the cooking device 10 adjusts the volume of the second divided body 220 , for example. In addition, the adjustment mechanism 80 adjusts the height of the internal container 250 .

[0057] The second split body unit 300 is provided to be movable relative to the housing 13. Since the first split body 210 is fixedly provided in the housing 13, the second split body unit 300 is movable relative to the first split body 210. The second split body unit 300 is movable, for example, in the up-down direction (Z direction). The second split body unit 300 may also be referred to as a lower container unit 300 or a lower kettle unit 300.

[0058] The second split body unit 300 is provided to be engageable and detachable with respect to the first split body 210. The adjustment mechanism 80 also adjusts the position of the second split body unit 300. That is, the adjustment mechanism 80 can also change the state of the container unit 20 between the first state and the second state by adjusting the position of the second split body unit 300.

[0059] The adjustment mechanism 80 includes an external mechanism 81 disposed outside the second split body unit 300 and an internal mechanism 82 disposed inside the second split body unit 300. The external mechanism 81 and the internal mechanism 82 are connected to each other. The external mechanism 81 is disposed inside the housing 13 and mounted on the housing 13. The external mechanism 81 is mounted on the base portion 13D, for example. The external mechanism 81 is driven by the drive unit 90 to operate. The drive unit 90 is, for example, an electric motor. More details about the adjustment mechanism 80 will be described later.

[0060] The housing 13 of the cooking device 10 includes a front portion 13A, a top portion 13B, a back portion 13C, and a base portion 13D. The housing 13 includes a first divided body 210, a high-frequency circuit 30, a controller 40, a temperature sensor 70, an adjustment mechanism 80, a drive unit 90, and the like.

[0061] The front portion 13A is provided with an input-output device 15. The input-output device 15 receives an input operation of the user on the cooking device 10, and outputs necessary information to the user. As an example, the input-output device 15 is a touch panel.

[0062] The heating cooker 10 includes an antenna 50. The antenna 50 radiates electromagnetic waves for heating the food to be cooked into the chamber 200. As an example, the antenna 50 is provided at the first segment 210. The number of antennas 50 may be one or more. The antenna 50 may also be provided at the second segment 220, but as described later, the antenna 50 is preferably provided only at the first segment 210 and not at the second segment 220. The illustrated antenna 50 is provided at a fixed position in the container unit 20, but the antenna 50 may also be provided movably in the container unit 20.

[0063] The frequency of the electromagnetic wave radiated from the antenna 50 is not particularly limited, and is, for example, 915 MHz (wavelength λ is about 328 mm). For example, the antenna 50 is a loop antenna. A loop antenna is an antenna in which a conductor element is formed into a loop. The number of turns of the loop is, for example, 1, but may be greater than 1. The element length of the conductor element of the loop antenna can be set to, for example, about λ / 2. The antenna 50 is, for example, Figure 1 As shown, the annular surface is provided above the mounting surface 250A so as to be substantially parallel to the mounting surface 250A (horizontal surface).

[0064] The antenna 50 is connected to the high frequency circuit 30 via a power supply line. The high frequency circuit 30 supplies high frequency power as electromagnetic wave radiation to the antenna 50. The high frequency circuit 30 is controlled by the controller 40.

[0065] The heating cooker 10 includes a heater 60 that radiates heat for heating the food. As an example, the heater 60 is an infrared heater that radiates infrared rays when powered. The heater 60 can be provided, for example, at a position above the placement surface 250. Figure 1 In the embodiment, the heater 60 is arranged near the antenna 50. The heater 60 is controlled by the controller 40.

[0066] The heating cooker 10 can heat the food to be cooked by using both or either of the electromagnetic waves radiated from the antenna 50 and the heat radiated from the heater 60. The electromagnetic waves are suitable for heating the inside of the food to be cooked. In addition, the heat radiated from the heater 60 is suitable for heating the surface of the food to be cooked. In addition, the heater 60 is also suitable for increasing the temperature in the chamber 200.

[0067] The heating cooker 10 is provided with a temperature sensor 70 for measuring the temperature of the chamber 200 (container unit 20). The temperature sensor 70 is provided, for example, at the first divided body 210. The temperature sensor 70 may be provided to measure the temperature outside the chamber 200, or may be provided to measure the temperature outside the chamber 200. The temperature sensor 70 is connected to the controller 40. The controller 40 controls the heater 60 based on the measured temperature. The controller 40 may also control the power or frequency of the electromagnetic wave radiated from the antenna 50 based on the measured temperature.

[0068] The heating cooker 10 includes a heat insulating material 17 for keeping the container unit 20 warm. Figure 1 In the embodiment, the heat insulating material 17 is provided so as to cover the first divided body 210. The heat insulating material 17 may be provided so as to cover the second divided body 220 as well.

[0069] Figure 2 The container unit 20A schematically shows the container unit 20 in the first state. In addition, for easy understanding, Figure 2 The container unit 20A shown is drawn with the first divided body 210 and the second divided body 220 slightly separated from each other.

[0070] Also like Figure 2 As shown, the chamber 200 includes a first partial chamber 210A formed inside a first divided body 210 and a second partial chamber 220A formed inside a second divided body 220 .

[0071] The first split body 210 includes a first opening 210B. The first split body 210 in the first state connects the first partial chamber 210A in the first split body 210 with the second partial chamber 220A in the second split body 220. As an example, the first opening 210B is a lower opening formed in the lower part of the first split body 210. The first split body 210 includes an upper surface portion 210D and a peripheral wall 210E extending downward from the entire periphery of the upper surface portion 210D. As an example, the upper surface portion 210D is circular. The first opening 210B is formed at the lower part of the peripheral wall 210E. As an example, the first partial chamber 210A in the first split body 210 is a space surrounded by the upper surface portion 210D and the peripheral wall 210E. The first partial chamber 210A is connected to the outside of the first split body 210 via the first opening 210B. As an example, the antenna 50 may be provided in the first divided body 210 .

[0072] The second split body 220 has a second opening 220B. The second split body 220 in the first state makes the second partial chamber 220A in the second split body 220 communicate with the first partial chamber 210A in the first split body 210. As an example, the second opening 220B is an upper opening formed in the upper part of the second split body 220. The second split body 220 has a lower surface portion 220D and a peripheral wall 220E formed by extending upward from the entire periphery of the lower surface portion 220D. As an example, the lower surface portion 220D is circular. The second opening 220B is formed in the upper part of the peripheral wall 220E. As an example, the second partial chamber 220A in the second split body 220 is a space surrounded by the lower surface portion 220D and the peripheral wall 220E. The second partial chamber 220A is communicated with the outside of the second split body 220 via the second opening 220B. As an example, a placement surface 250A for placing the food to be cooked is provided in the second divided body 220. In addition, the peripheral wall 220E is stretchable in the vertical direction. This will be described later.

[0073] Figure 2 The container unit 20B schematically shows the container unit 20 in the second state (open state) in which the first split body 210 and the second split body 220 are separated from each other. Here, as an example, the first split body 210 is set at a fixed position of the cooking device 10 and does not move, but the first split body 210 and the second split body 220 are separated by the movement of the second split body 220. As an example, the second split body 220 is set to be movable in the vertical direction (Z direction), and is separated from the first split body 210 by moving downward from the position in the first state.

[0074] In the second state, the first opening 210B and the second opening 220B are separated from each other. In the second state, the first partial chamber 210A and the second partial chamber 220A are separated, and the chamber 200 is open to the outside through the first opening 210B and the second opening 220B. In this way, the single chamber 200 of the container unit 20 of the embodiment can be divided into a plurality of partial chambers 210A and 220A. Such a container unit 20 can also be called a chamber division type container unit 20.

[0075] In the second state, the food 100 can be placed in the second partial chamber 220A from the second opening 220B of the second divided body 220. The food 100 placed in the second divided body 220 is placed on the placement surface 250A. In addition, the food 100 can also be placed on the placement surface 250A via a plate or the like (not shown). In the second state, the food 100 stored in the container unit 20B can also be taken out from the second opening 220B to the outside of the container unit 20B.

[0076] Figure 2The container unit 20C schematically shows the container unit 20 returning from the second state to the first state. The second split body 220 in the second state moves upward, and the upper portion of the peripheral wall 220E of the second split body 220 is closely fitted with the lower portion of the peripheral wall 210E of the first split body 210, thereby blocking the first opening 210B and the second opening 220B, and forming a single chamber 200 in which the first partial chamber 210A and the second partial chamber 220A are closed. In this way, the container unit 20 is configured to be able to change its form between the first state and the second state.

[0077] The chamber 200 formed inside the container unit 20 forms a resonant cavity (resonant cavity) that resonates with the electromagnetic wave radiated from the antenna 50 in the first state. The resonant cavity is generally used as a cavity resonator (cavity resonator) for oscillating microwaves. The cavity resonator is generally used as a microwave filter or a microwave oscillator. The cavity resonator has a closed space surrounded by a conductor wall such as metal, namely a cavity (cavity). The frequency (wavelength) of the resonance of the cavity resonator is determined by the size and shape of the cavity. For example, if it is a cylindrical cavity resonator having a structure in which both ends of a cylindrical waveguide are short-circuited by a conductor, the resonant frequency is determined by the radius of the cylindrical cavity and the axial length of the cylinder.

[0078] In the embodiment, in the first state, the size and shape of the first split body 210 and the second split body 220 are set so that the chamber 200 becomes a resonant cavity. The plurality of split bodies 210 and 220 are closely connected to each other in the first state, so that they can be regarded as a single conductive container forming a closed space that becomes a resonant cavity. The design method of the size and shape of the first split body 210 and the second split body 220 involved in the embodiment can follow the design method of the resonant cavity in the chamber resonator. In addition, the container unit 20 forming the resonant cavity is connected to the ground potential.

[0079] In addition, if a little energy loss is allowed, since the frequency that can resonate in the resonant cavity has a predetermined width, the frequency as the design value of the resonant cavity may be slightly different from the frequency of the electromagnetic wave radiated from the antenna 50. For example, the frequency as the design value of the resonant cavity is preferably in the range of 80% to 120% of the frequency of the electromagnetic wave radiated from the antenna 50, and more preferably in the range of 90% to 110% of the frequency of the electromagnetic wave radiated from the antenna 50. However, the Q value of the resonant cavity is large, and the frequency band that can resonate is not too wide. In addition, the resonant frequency of the resonant cavity that accommodates the cooked object 100 can change according to the size, material, material state, distance between the cooked object and the antenna, etc. In addition, the material state refers to, for example, a frozen state in which the water content in the cooked object 100 is fixed, or a refrigerated and room temperature state in which the water content is liquid. The material state may also be a state represented by the amount of water in the cooked object 100. The material state of the cooked object 100 can change as cooking proceeds.

[0080] Thus, the characteristics of the container unit 20 as a resonance cavity can also be changed according to the food 100 placed in the container unit 20. That is, the resonance frequency can be changed according to the food 100. Therefore, when designing the resonance cavity, it is preferable to consider the size and characteristics of the food 100 to be cooked.

[0081] In addition, since the size and type of the food to be cooked 100 are various, the resonant frequency can be changed according to the size and type of the food to be cooked 100. In addition, the resonant frequency may also change according to the change in the characteristics of the food to be cooked 100 caused by the progress of cooking. In order to cope with the change in the resonant frequency, for example, the distance between the antenna 50 and the food to be cooked 100 can be adjusted. Therefore, the container unit 20 of the embodiment is configured so that the distance from the placement surface 250A of the food to be cooked 100 to the antenna 50 is variable. By adjusting the distance between the antenna 50 and the food to be cooked 100, the loss of electromagnetic waves caused by the change in the resonant frequency can be suppressed, thereby efficiently heating. In addition, the adjustment corresponding to the change in the resonant frequency can also be the adjustment of the volume of the container unit 20. Therefore, the container unit 20 of the embodiment is configured so that the volume of the container unit 20 is variable. By adjusting the volume of the container unit 20 (the volume of the chamber 200), the loss of electromagnetic waves can be suppressed, thereby efficiently heating. In addition, the volume of the container unit 20 may also be fixed.

[0082] When the frequency of the electromagnetic wave radiated from the antenna is 915 MHz, as an example, the height H1 of the first partial cavity 210A in the first partition 210 can be about 150 mm to 250 mm. In addition, as an example, the height H2 of the second partial cavity 220A in the second partition 220 can be about 150 mm to 250 mm. However, the heights H1 and H2 can be variable. In addition, the overall shape of the cavity 200 can be roughly cylindrical. The diameter R of the cylindrical cavity 200 can be about 250 mm to 300 mm. In addition, the overall shape of the cavity 200 can also be a polygonal cylinder such as a quadrilateral cylinder. The frequency band of 915 MHz can form a resonant cavity as a cooking chamber of appropriate size, so it is preferred.

[0083] like Figure 2 As shown in FIG. 1 , the food 100 is stored in the second divided body 220. Figure 2 In the second partial chamber 220A (internal space of the second divided body 220) shown, the space above the placement surface 250A becomes a cooking storage space S for placing the cooking placed on the placement surface 250A. The antenna 50 provided in the first divided body 210 is located above the cooking storage space S. Therefore, the antenna 50 is arranged so that the cooking storage space S for placing the cooking placed on the placement surface 250A exists between the antenna 50 and the placement surface 250A in the container unit 20.

[0084] In addition, from the perspective of the antenna 50, there is a cooking storage space S between the antenna 50 and the placement surface 250A with a margin space M therebetween. That is, there is a margin space M between the cooking storage space S and the antenna 50. The margin space M is a space where the cooking object 100 does not exist. Figure 2 As shown, the first partial chamber 210A (internal space of the first divided body 210 ) serves as a margin space M. The presence of the margin space M allows the placement surface 250A to be moved so that the food 100 is brought close to the antenna 100 .

[0085] The optimal electromagnetic wave radiation conditions may differ depending on the size of the object 100. Therefore, immediately after the object 250A is placed on the placement surface 250A (hereinafter referred to as the "initial state", and the position of the placement surface 250A in the initial state is referred to as the "first position" or "initial position"), the margin space M is used to ensure that the distance between the object 100 and the antenna 50 is large in advance, so that the object 100 that needs a large distance can be handled. In addition, for the object 100 that is desired to be at a smaller distance, the placement surface 250A is moved so that the object 100 enters the margin space M, so that the distance between the object 100 and the antenna 50 can be reduced. In this way, the margin space M becomes an adjustment margin for moving the object 100 to approach the antenna 50.

[0086] Assuming that there is no margin space M, when the distance between the object 100 and the antenna 50 is small in the initial state, in order to change the distance between the object 100 and the antenna 50, the object 100 needs to be moved away from the antenna 50 from the initial state. However, as the heating progresses, the object 100 moves toward the antenna 50. Therefore, after temporarily moving the object 100 away from the antenna 50, it is necessary to perform an operation of moving the object 100 toward the antenna 50, which is very cumbersome.

[0087] On the other hand, as in the present embodiment, in the initial state, by providing a margin space M as an adjustment margin between the antenna 50 and the object 100, it is possible to move the object 100 close to the antenna 50 for the object 100 that is desired to be at a smaller distance, and even when heating is advanced, it is possible to move the object 100 close to the antenna 50, which is advantageous. In addition, the larger the distance between the antenna 50 and the object 100, the smaller the influence on the change of the resonance frequency. Therefore, from this point of view, the existence of the margin space M is also advantageous. In addition, the antenna 50 may also be movable in the margin space M. That is, the margin space M may be a space for allowing the antenna 50 movably provided in the container unit 20 to move.

[0088] In addition, in the present embodiment, due to the structure of the container unit 20, in the initial state, it is impossible for the food 100 to be cooked to exist in the remaining space M. This point will be described later.

[0089] Figure 3 2 shows an exploded cross-sectional view of the container unit 20. Figure 3As shown, the first segment 210 has a circular upper surface portion 210D and a cylindrical peripheral wall 210E extending downward from the periphery of the upper surface portion 210D. The first segment 210 has an expanded diameter portion 210F extending radially outward from the entire periphery of the lower end of the peripheral wall 210E. The lower surface 210G of the expanded diameter portion 210F (the surface on the side of the second segment 220) becomes the first contact surface 210G that contacts the second segment 220 in the first state. The first contact surface 210G is formed on the entire circumference of the lower end of the peripheral wall 210E and has an annular shape. As an example, the first contact surface 210G becomes an inclined surface that faces upward as it faces the radially outward direction. In addition, the expanded diameter portion 210F can also be formed horizontally facing the radially outward direction without being inclined. The lower surface of the horizontal expanded diameter portion 210F becomes the first contact surface 210G.

[0090] The first split body 210 includes a shielding material 210H mounted on the first contact surface 210G. The shielding material 210H is formed of a conductor similar to the first split body 210. The shielding material 210H is formed in an annular shape and is arranged over the entire circumference of the annular first contact surface 210G. The shielding material 210H prevents electromagnetic waves from leaking between the first contact surface 210G of the first split body 210 and the second contact surface 223A of the second split body 220 in the first state. In addition, the shielding material 210H may also be provided on the second split body 220 side.

[0091] The shielding material 210H is configured to be softer than the first split body or to be more elastically deformable than the first split body. The shielding material 210H can be configured, for example, by forming a shielding mesh into a ring shape. Such a shielding material 210H ensures the close contact between the first split body 210 and the second split body 220, and stabilizes the electrical characteristics of the joined first split body 210 and second split body 220. The contact state between the first split body 210 and the second split body 220 affects the resonant frequency of the resonant cavity 200. However, if the shielding material 210H is interposed between the first split body 210 and the second split body 220, the shielding material 210H can ensure a stable contact state between the two split bodies 210 and 220, and suppress the change in the resonant frequency. In addition, the shielding material 210H can suppress the loss of electromagnetic waves, thereby efficiently performing heating.

[0092] The second split body 220 includes a main body 221 and a sliding portion 225 slidably disposed in the vertical direction relative to the main body 221. The main body 221 is disposed in a fixed position relative to the unit housing 310 of the second split body unit 300. Therefore, the main body 221 moves together with the unit housing 310. On the other hand, the sliding portion 225 is slidably disposed in the vertical direction within the unit housing 310. By sliding the sliding portion 225 in the vertical direction relative to the main body 221, the volume of the second partial chamber 220A in the second split body 220 changes. By changing the volume of the second partial chamber 220A, the volume of the entire chamber 200 changes.

[0093] The main body 221 of the second split body 220 includes an inner cylinder portion 222 constituting a part of the peripheral wall 220E of the second split body 220 and a tapered portion 223 extending from the upper portion of the inner cylinder portion 222. The inner cylinder portion 222 is a cylindrical shape with openings at the top and bottom. The tapered portion 223 is inclined in such a way that the opening diameter becomes larger as it moves upward. The inner surface of the tapered portion 223 becomes the second contact surface 223A that contacts the first contact surface 210G of the first split body 210. The second contact surface 223A is parallel to the first contact surface 210G. The second contact surface 223A contacts indirectly or directly via the shielding material 210H. The second contact surface 223A is also annular. In addition, the tapered portion 223 can also be a horizontal ring portion 223 extending horizontally from the upper portion of the inner cylinder portion 222 in the radially outward direction. The upper surface of the horizontal ring portion 223 is a horizontal second contact surface 223A parallel to the first contact surface 210G which is the lower surface of the horizontal enlarged diameter portion 210F of the first divided body 210 .

[0094] If the electromagnetic wave is to leak to the outside from between the first contact surface 210G and the second contact surface 223A, the electromagnetic wave needs to be directed obliquely upward. However, the electromagnetic wave from the antenna 50 toward the food 100 is mainly directed downward, so the structure of the contact surfaces 210G and 223A itself can also suppress the electromagnetic wave from leaking from between the first contact surface 210G and the second contact surface 223A. In this way, the cone 223 is preferably formed in a manner that the opening diameter becomes wider as it is closer to the antenna 50.

[0095] The second split body 220 can also include an outer cylinder portion 222A mounted on the inner cylinder portion 222. The outer cylinder portion 222A is a cylindrical shape with a larger diameter than the inner cylinder portion 222, and is arranged concentrically with the inner cylinder portion 222 on the radially outer side of the inner cylinder portion 222. The upper portion of the outer cylinder portion 222A is mounted on the inner cylinder portion 222, and the upper portion of the outer cylinder portion 222A is closed. The lower end of the outer cylinder portion 222A extends further downward than the lower end of the inner cylinder portion 222. The lower portion of the outer cylinder portion 222A is open. The space between the outer peripheral surface of the inner cylinder portion 222 and the inner peripheral surface of the outer cylinder portion 222A is a sliding space for the sliding portion 225 to be inserted.

[0096] The sliding portion 225 of the second split body 220 includes a cylinder 226 and a bottom 227 provided at the lower portion of the cylinder 226. The upper portion of the cylinder 226 is open. The cylinder 226 constitutes a portion of the peripheral wall 220E of the second split body 220. The upper portion of the cylinder 226 is inserted into the sliding space between the outer peripheral surface of the inner cylinder 222 and the inner peripheral surface of the outer cylinder 222A. The bottom 227 constitutes the lower surface portion 220D of the second split body 220.

[0097] The bottom 227 has an insertion hole 228. The operating body 820 provided in the adjustment mechanism 80 is inserted into the insertion hole 228 so as to be movable in the vertical direction. The operating body 820 pushes down the sliding part 225 by moving downward. In addition, the operating body 820 pushes up the inner container 250 by moving upward. The operating body 820 has a vertical direction (Z direction) length required to push up the inner container 250. Figure 1 and Figure 4 The vertical length of the operating body 820 shown is only an example and is not particularly limited. By increasing the vertical length of the operating body 820, the inner container 250 can be pushed up significantly. The vertical length of the operating body 820 can also be Figure 1 and Figure 4 Approximately 2 to 3 times the length shown.

[0098] The sliding part 225 includes an abutting part 229. The abutting part 229 abuts against a stopper 311 provided on the unit housing 310 of the second split body unit 300, thereby preventing the sliding part 225 from moving upward. Therefore, the sliding part 225 is movable within a range below the position where the abutting part 229 abuts against the stopper 311.

[0099] Figure 4 The operation of the inner container 250 and the sliding portion 225 based on the operation of the operating body 820 is shown. Figure 4 The second split body unit 300A shows Figure 1 The state of the second split body unit 300 shown in FIG. 1 is a state in which the inner container 250 is pushed upward. Figure 4 The second split body unit 300B shows the Figure 1 The state of the second split body unit 300 shown is a state where the sliding portion 225 is pushed down.

[0100] The internal mechanism 82 having the operating body 820 has a first operating arm 825 that is freely movable up and down in the unit housing 310. The first operating arm 825 extends to the outside of the unit housing 310 and is connected to the external mechanism 81. The first operating arm 825 is moved up and down by the external mechanism 81. The internal mechanism 82 has a spring 827 provided between the first operating arm 825 and the abutment portion 229 provided on the sliding portion 225. As an example, the spring 827 is a compression spring. The spring 827 biases the first operating arm 825 that is pushed up downward.

[0101] The operating body 820 includes an insertion body 821 inserted into the insertion hole 228 (see Figure 3 ); and an operating head 823, which is disposed at the upper portion of the insertion body 821 and has a larger diameter than the insertion hole 228. The insertion body 821 is configured to be movable up and down in the insertion hole 228. The operating head 823 is located inside the sliding portion 225. The operating head 823 is larger than the insertion hole 228, and thus is prevented from slipping out of the insertion hole 228 to the outside of the sliding portion 225.

[0102] like Figure 4 When the first operating arm 825 is driven to rise, the operating head 823 of the operating body 820 rises, as shown in the second split body unit 300A shown in FIG. 1 . The rising operating head 823 abuts against the inner container 250 from below, pushing the inner container 250 upward. As a result, the distance between the inner container 250 (the mounting surface 250A) and the antenna 50 is reduced. In addition, when the first operating arm 825 rises, the interval between the first operating arm 825 and the abutting portion 229 is reduced, and the spring 827 is compressed.

[0103] When the upward driving force of the first operating arm 825 is released, the first operating arm 825 is lowered by the biasing force of the spring 827. Alternatively, the first operating arm 825 may be lowered by gravity alone.

[0104] When the first operating arm 825 is lowered and returned to the original position, the operating head 823 is also lowered. As the operating head 823 is lowered, the inner container 250 is lowered due to its own weight. The inner container 250 is lowered until the engaging portion 250D is engaged with the engaged portion 224. When the engaging portion 250D is engaged with the engaged portion 224, the inner container 250 is held at this position.

[0105] In addition, if Figure 4 When the first operating arm 825 is driven downward, the operating head 823 is lowered, as shown in the second split body unit 300B. The lowered operating head 823 contacts the sliding part 225 from above and pushes down the sliding part 225. As a result, the sliding part 225 moves downward relative to the main body 221 of the second split body 220. As a result, the volume of the second split body 220 increases.

[0106] Furthermore, when the first operating arm 825 rises and returns to its original position, the sliding portion 225 supported by the first operating arm 825 via the spring 827 and the contact portion 229 also returns to the upper position, and the volume of the second divided body 220 is restored.

[0107] return Figure 1 , the external mechanism 81 in the adjustment mechanism 80 is described. The external mechanism 81 includes a first shaft 810 that is rotationally driven by the driving unit 90. The first shaft 810 is a shaft extending in the up-down direction and is rotatably arranged around an axis in the up-down direction. The first shaft 810 is, for example, vertically arranged on the base portion 13D. The first shaft 810 is a screw shaft and includes a lifting portion 811 that moves linearly up and down by the rotation of the first shaft 810. When the rotation of the driving unit 90 is transmitted to the first shaft 810 via a transmission belt or the like, the lifting portion 811 rises or falls by the rotation of the first shaft 810. The rise and fall are switched according to the rotation direction of the first shaft 810.

[0108] The external mechanism 81 includes a second shaft 812 erected in parallel with the first shaft 810. The second shaft 812 is, for example, erected on the base portion 13D. The second shaft 812 includes an upper lifting body 813 and a lower lifting body 814 that are movable in the axial direction (up and down direction) of the second shaft 812. The second shaft 812 guides the up and down movement of the upper lifting body 813 and the lower lifting body 814. The upper lifting body 813 is mounted on the first operating arm 825 extending from the internal mechanism 82. Therefore, the up and down movement of the first operating arm 825 is guided by the second shaft 812 via the upper lifting body 813. In addition, the lower lifting body 814 is mounted on the second operating arm 815 mounted on the second split body unit 300. Therefore, the up and down movement of the second operating arm 815 is guided by the second shaft 812 via the lower lifting body 814.

[0109] When the lifting part 811 provided on the first shaft 810 is Figure 1 When the position shown is raised, the first operating arm 825 can be pushed up. When the lifting part 811 is lowered from the state where the first operating arm 825 is pushed up, the first operating arm 825 is also lowered. The inner container 250 and the sliding part 225 move according to the amount of the first operating arm 825 rising.

[0110] When the lifting unit 811 is Figure 1When the position shown in FIG. 1 is lowered, the second operating arm 815 abuts against the second operating arm 815, and the second operating arm 815 can be pushed down. The second operating arm 815 is installed on the unit housing 310 of the second split body unit 300, so when the second operating arm 815 is lowered, the second split body unit 300 is lowered as a whole. As a result, the second split body unit 300 is separated from the first split body 210. When the second operating arm 815 is lowered, the spring 816 provided between the lower lifting body 814 and the base portion 13D is compressed.

[0111] When the downward driving force of the second operating arm 815 is released, the second operating arm 815 rises due to the biasing force of the spring 816. The second split body unit 300 rises due to the rise of the second operating arm 815. Thus, the second split body unit 300 can be joined to the first split body 210. The joined state is made tight by the biasing force of the spring 816.

[0112] In the illustrated embodiment, the lifting and lowering of the inner container 250, the lifting and lowering of the second split body unit 300, and the volume adjustment of the second split body 220 are performed by a single driving unit 90, but they may be performed by different driving sources 90.

[0113] Figure 5 The circuit diagram of the heating cooker 10 is shown. The antenna 50 is connected to the high-frequency circuit 30 that outputs high frequency. The high-frequency circuit 30 includes an amplifier 31 that amplifies the high frequency output from an oscillation circuit (not shown). The output of the amplifier 31 is supplied to the antenna 50. The antenna radiates the high frequency supplied from the high-frequency circuit as electromagnetic waves for heating. The high-frequency circuit 30 includes a monitoring circuit 33 that monitors reflected waves. When the reflected wave of the electromagnetic wave radiated from the antenna 50 is large, the loss becomes large. The monitoring circuit 33 monitors the reflected wave and provides the monitoring result to the controller 40. In addition, the reflected wave here is an electromagnetic wave that is not absorbed by the cooked object 100, etc. and is received by the antenna 50. In addition, the high-frequency circuit 30 can also provide the controller 40 with the operation status other than the reflected wave. In Figure 5 30A is also shown in another example of a high frequency circuit. The high frequency circuit 30A of another example includes a circulator 35 connected to the output side of the amplifier 31. The circulator 35 outputs the high frequency output from the amplifier 31 to the antenna 50 side. In addition, the circulator 35 outputs the reflected wave to the dummy load 37 (terminator) side. The circulator 35 prevents the reflected wave from flowing to the amplifier 31 side.

[0114] The controller 40 uses the monitoring circuit 33 and the like to monitor the operating state of the high-frequency circuit 30, and controls the driving unit 90 according to the operating state of the high-frequency circuit 30. The controller 40 controls the driving unit 90, for example, by adjusting the volume of the second split body 220 or adjusting the distance between the placement surface 250A and the antenna 50 to suppress the reflected wave. In this way, the reflected wave can be suppressed and the loss can be reduced. If the loss is reduced, the chamber 200 becomes a more ideal resonant cavity, and the object 100 can be heated efficiently. In addition, in order to adjust the distance between the placement surface 250A and the antenna 50, the controller 40 can also control the movement of the placement surface 250, or the movement of the antenna 50.

[0115] The operating state of the high-frequency circuit 30 monitored by the controller 30 is, for example, the return loss (reflection loss) of the high frequency. The return loss indicates the ratio of the traveling wave transmitted by the high-frequency circuit 30 to the reflected wave. The controller 30 can adjust the volume of the second split body 220 or adjust the distance between the mounting surface 250A and the antenna 50 to search for the volume or the position of the mounting surface 250A where the return loss becomes small. By radiating electromagnetic waves in a state where the return loss becomes small, efficient heating can be performed. Another example of the operating state of the high-frequency circuit 30 monitored by the controller 30 is the power consumption, gain or frequency of the high frequency in the high-frequency circuit 30. By controlling the drive unit 90 in accordance with the operating state of the high-frequency circuit 30, the characteristics of the container unit 20 can be changed.

[0116] The controller 40 is also connected to the input / output device 15, the heater 60, and the temperature sensor 70. The controller 40 can perform control in accordance with a user operation provided from the input / output device 15. The controller 40 can control the heater 60 based on a temperature measurement result of the temperature sensor 70.

[0117] Figure 6 The operation of the cooking device 10 controlled by the controller 40 is shown. The operation of the cooking device 10 is realized by, for example, a processor of the controller 40 executing a computer program stored in a memory of the controller 40.

[0118] First, in order to place the food 100 in the container unit 20, the lower pot unit 300 (the second split body unit 300) is lowered (step S61). The lower pot unit 300 is lowered, for example, based on the user's operation on the input device 15. The lower pot unit 300 may also move horizontally after being lowered in step S61 (see Figure 7). In addition, the lower pot unit 300 may be moved horizontally without being lowered. Then, the user places the food 100 in the inner container 250 of the lower pot 220 (the second split body 220) (step S61A). Then, the lower pot unit 300 rises (step S62). In the case where the lower pot unit 300 moves horizontally, it may be moved in a manner that returns to the original position in the horizontal direction before rising. In addition, it may be moved only in a manner that returns to the original position in the horizontal direction.

[0119] By step S62, the lower pot 220 (the second segment 220) is tightly fitted with the upper pot 210 (the first segment 210). In addition, as described above, the lower pot 220 can also move horizontally relative to the upper pot 210 in the lowered state (refer to Figure 7 ). When the lower pot 220 moves in the horizontal direction, even if the upper and lower intervals between the lower pot 220 and the upper pot 210 are small after separation, the food 100 can be easily put in and out of the lower pot 220. Figure 7 As shown, the lower pot 220 can move linearly in the front-rear direction (Y direction), or can move in a circular arc in the horizontal plane (XY plane).

[0120] When the lower kettle 220 moves horizontally, Figure 1 The first operating arm 825 shown is preferably provided in a telescopic manner to allow the movement of the lower pot 220. For example, it is preferred that the first operating arm 825 includes a first member provided in the direction external mechanism 81 and a second member provided in the lower pot 220, and the second member is provided in a manner that is movable in the horizontal direction relative to the first member. In addition, the second operating arm 815 is also preferably provided in a telescopic manner to allow the movement of the lower pot 220. For example, it is preferred that the second operating arm 815 includes a first member provided in the external mechanism 81 and a second member provided in the lower pot 220, and the second member is provided in a manner that is movable in the horizontal direction relative to the first member. In addition, the horizontal movement of the lower pot 220 can be performed by manpower or driven by a driving source.

[0121] In addition, a user operation for setting cooking conditions is performed (step S63). The cooking conditions are, for example, the finished state of the food or the heating time desired by the user. According to the set cooking conditions, heating conditions such as the power of the electromagnetic wave, the radiation timing, the radiation time, the temperature of the heater, and the heating time based on the heater are set. In addition, the setting of the cooking conditions in step S63 can also be performed before step S61.

[0122] When the object 100 to be cooked is arranged in the container unit 20, in order to apply the best electromagnetic wave to the object 100 to be cooked, the volume of the lower pot 220 and the distance from the placement surface 250A of the internal container 250 to the antenna 50 are adjusted (step S64). The adjustment may be only one of the volume adjustment and the distance adjustment. In order to make the adjustment, the reflected wave of the electromagnetic wave radiated from the antenna 50 is measured by the monitoring circuit 33. The controller 40 performs volume adjustment and distance adjustment to reduce the reflected wave. These adjustments are performed, for example, in the following manner: electromagnetic waves are radiated from the antenna 50, and the volume and distance are appropriately changed to determine the volume and distance when the reflected wave is minimized. In addition, when the distance (second distance) from the placement surface 250A to the antenna 50 changes, the first distance between the antenna 50 and the object 100 to be cooked changes.

[0123] When the adjustment in step S64 is completed, the heating of the object 100 is started (step S65 ). The heating is performed by either or both of the electromagnetic wave radiation from the antenna 50 and the heat radiation from the heater 60 .

[0124] During heating based on electromagnetic wave radiation, the operating state of the high-frequency circuit 30 is also intermittently monitored. As an example, the monitoring of the operating state here is the monitoring of reflected waves. The controller 40 can also perform volume adjustment and distance adjustment during heating to reduce the reflected waves (step S66). Even if the characteristics of the cooked object 100 change due to heating, and the overall resonant frequency of the container unit 20 containing the cooked object 100 changes, the adjustment made during heating can be used to suppress the change in the resonant frequency, thereby suppressing the loss of electromagnetic waves. As the heating progresses, the resonant frequency decreases, and it is preferable to reduce the first distance between the antenna 50 and the cooked object 100, so the distance adjustment during heating is mainly controlled in a manner of reducing the distance.

[0125] Figure 8 The container unit 20D schematically shows a container unit 20 with a relatively small volume. Figure 8 The container unit 20E schematically shows a container unit 20 having a relatively large volume. In the container unit 20D, the height of the second segment 220 is H2-1. In the container unit 20E, the height of the second segment 220 is H2-2, which is larger than that of the container unit 20D. Due to the influence of the food 100, the resonance frequency of the entire container unit 20D including the food 100 changes. Therefore, in order to eliminate this change, a more ideal resonance cavity can be obtained by adjusting the volume of the container unit 20. Since the volume can be adjusted, it is possible to appropriately respond to various food 100.

[0126] Fig. 9The container unit 20F schematically shows a container unit 20 in which the distance D1 from the placement surface 250A to the antenna 50 is relatively large. Fig. 9 The container unit 20G shows a container unit 20 in which the distance D2 from the placement surface 250A to the antenna 50 is medium. Fig. 9 The container unit 20H shows a container unit 20 having a relatively small distance D3 from the placement surface 250A to the antenna 50. Due to the influence of the food 100, the overall resonance frequency of the container unit 20D including the food 100 changes. Therefore, in order to eliminate this change, a more ideal resonance cavity can be obtained by adjusting the position of the placement surface 250A of the food 100.

[0127] Furthermore, by performing both the volume adjustment and the distance adjustment, the adjustment margin becomes larger than when only one of them is adjusted, which is advantageous.

[0128] Fig. 9 The position P1 of the placement surface 250A in the container unit 20F can correspond to the initial position P1 (first position) before the electromagnetic wave is radiated from the antenna 50. The initial position P1 before the electromagnetic wave is radiated is that the food 100 is contained in the container unit 20, the container unit 20 is in a closed state, but the electromagnetic wave is radiated ( Figure 7 The initial position refers to the position of the placing surface 250A before the adjustment of step S64). That is, the initial position is the position before the adjustment of step S64. As an example, the initial position P1 of the placing surface 250A is the position where the distance (second distance) between the antenna 50 and the placing surface 250A is the largest. In this case, when the position of the placing surface 250A is adjusted, the distance between the antenna 50 and the placing surface 250A becomes smaller. The position of the placing surface 250A adjusted from the initial position P1 is also referred to as the "second position". The second position may be a position closer to the antenna 50 than the first position which is the initial position. When the distance (second distance) between the antenna 50 and the placing surface 250A becomes smaller, the distance (first distance) between the antenna 50 and the cooked object 100 also becomes smaller.

[0129] The controller 40 can adjust the position of the placement surface 250A to the second position during the radiation of the electromagnetic wave for the adjustment in step S64 . Fig. 9 The positions of the placement surfaces 250A in the container units 20G and 20H are respectively the second positions. When the placement surfaces 250A move to the second positions, the food 100 can be present in the remaining space M (internal space of the first divided body).

[0130] Then, when the heating is finished (step S67), the lower pot unit 300 (second split body unit 300) is lowered (step S68) in order to take out the food 100 in the container unit 20. The lowering of the lower pot unit 300 is performed, for example, according to a user operation. Then, the user takes out the food 100 from the inner container 250 of the lower pot 220 (second split body 220) (step S68A). Then, the lower pot unit 300 is raised (step S69). When taking out, the lower pot unit 300 may also move horizontally (refer to Figure 7 ).

[0131] Fig.10 and Fig.11 2 shows the radiation of electromagnetic waves E from antenna 50. Fig.11 As shown, when the antenna 50 is a loop antenna, the electromagnetic waves are mainly radiated in the radially outward direction of the loop antenna. Therefore, the electromagnetic waves radiated from the antenna 50 are mainly reflected by the peripheral wall 210E of the first segment 210 at the ground potential and reach the cooked object 100, and the electromagnetic waves directly reaching the cooked object 100 from the antenna 50 are relatively small.

[0132] The container unit 20 described above by way of example is a split structure, which is suitable for suppressing the deterioration of the characteristics of the resonant cavity. For example, in the container unit 20 of the embodiment, the joint portion of the plurality of split bodies 210 and 220 is relatively far from the antenna 50, so even if the plurality of split bodies 210 and 220 can be separated, the change of the resonant frequency of the resonant cavity can be suppressed.

[0133] That is, the resonant frequency of the resonant cavity is affected by the size and shape of the container unit 20, but the closer the portion of the container unit 20 is to the antenna 50, the greater the influence on the change of the resonant frequency. Therefore, the closer the joint between the first split body 210 and the second split body 220 is to the antenna 50, the greater the influence on the change of the resonant frequency. The joint between the first split body 210 and the second split body 220 is a portion where the electrical characteristics (such as impedance) may change every time the joint and separation are repeated. If the tightness of the first split body 210 and the second split body 220 changes or decreases, a potential difference may be generated between the first split body 210 and the second split body 220. The resonant cavity preferably has the same potential for the entire conductor surrounding the cavity, but if a potential difference occurs in the second split body 220 relative to the first split body 210, the characteristics of the resonant cavity change. Moreover, when the tightness of the second split body 220 relative to the first split body 210 changes, such as Fig.10 As shown, even if the first divided body 210 is connected to the ground potential, the potential of the second divided body 220 deviates from the ground potential.

[0134] On the other hand, in the container unit 20 of the embodiment, the joining portion between the first divided body 210 and the second divided body 220 is relatively far from the antenna 50 , so that the fluctuation of the resonance frequency can be suppressed.

[0135] Moreover, if Fig.10 As shown, the first segment 210 provided with the antenna 50 is connected to the ground potential and serves as a reflection surface of the electromagnetic wave E radiated from the antenna 50. The electromagnetic wave E radiated from the antenna 50 is reflected by the first segment 210 and reaches the object 100. In order not to impair the reflection characteristics of the electromagnetic wave E, it is desirable that the reflection surface of the container unit 20 is at the ground potential. However, when the joint portion between the first segment 210 and the second segment 220 is located near the antenna 50, the electromagnetic wave E is reflected at the second segment 220 connected to the ground potential via the first segment 210. The second segment 220 may deviate from the ground potential, so the reflection characteristics of the electromagnetic wave E are impaired, and the heating efficiency by the electromagnetic wave is reduced. In contrast, in the container unit 20 of the embodiment, the joint portion between the first segment 210 and the second segment 220 is relatively far from the antenna 50. Therefore, the reflection of the electromagnetic wave E radiated from the antenna 50 is mainly performed in the first segment 210 directly connected to the ground potential until it reaches the object 100. As a result, the loss of electromagnetic waves can be suppressed.

[0136] The first split body 210 provided with the antenna 50 is fixedly provided, and therefore does not require a mechanism 80 for moving the second split body 220, which is movable. Figure 2 , 8 In any of the actions shown in FIGS. 9 and 9 , the first segmented body 210 does not move.

[0137] In addition, the first split body 210 does not extend or retract in the vertical direction like the second split body 220, so the mechanism 80 for extending or retracting is not required. Furthermore, the inner container 250 is raised or lowered in the second split body 220, so the first split body 210 does not need the mechanism 80 for raising or lowering the inner container 250. Fig. 9 In the illustrated operation, even if the position of the inner container 250 changes, the position of the first split body 210 does not change. Thus, the position of the first split body 210 does not change, and no movable member is attached.

[0138] If the first split body 210 moves or the first split body 210 undergoes deformation such as expansion and contraction, the resonant frequency may change. In addition, the presence or operation of the mechanism 80 for moving the first split body 210 may cause the resonant frequency to change. In contrast, in the embodiment, the first split body 210 provided with the antenna 50 does not move, and there is no operation caused by the mechanism 80, so the change of the resonant frequency can be suppressed. In addition, the second split body 220 is far away from the antenna 50, so even if it moves or is operated by the mechanism 80, the influence on the resonant frequency is relatively small, which is advantageous.

[0139] Thus, the first segment 210 makes the first partial cavity 210A in the entire cavity 200, which is located near the antenna 50, a stable space where no movement occurs and changes in electrical characteristics are suppressed. By making the first partial cavity 210A near the antenna 50 a stable space in advance, changes in the resonant frequency can be suppressed.

[0140] In order to suppress the fluctuation of the resonance frequency, the first partial cavity 210A formed as a stable space on the side close to the antenna 50 preferably occupies as large a proportion of the cavity 200 as possible. For example, the volume of the first partial cavity 210A is preferably 20% or more of the volume of the entire cavity 200, more preferably 30% or more, and even more preferably 40% or more. However, the second partial cavity 220A also needs a volume sufficient to accommodate the food 100. Therefore, the volume of the first partial cavity 210A is preferably 80% or less of the volume of the entire cavity 200, more preferably 70% or more, and even more preferably 60% or more.

[0141] More specifically, the volume of the first partial chamber 210A is preferably 20% to 80% of the volume of the entire chamber 200 , more preferably 30% to 70%, and even more preferably 40% to 60%.

[0142] Fig.12 The cooking object storage space S and the remaining space M in the container unit 20 are shown. In the present embodiment, as an example, the remaining space M is a space where the cooking object 100 cannot exist due to the structure of the container unit 20 .

[0143] Fig.12 The container unit 20J schematically shows the container unit 20 before storing the food 100. The container unit 20J is Figure 6 The container unit 20 is in the state before step S61. Fig.12The container units 20K and 20L schematically show the container unit 20 in a state where the lower pot 220 is horizontally moved relative to the upper pot 210. As in the container unit 20K, in a state where the lower pot 220 is horizontally moved, the food 100 is placed in the lower pot 220 from the second opening 220B of the lower pot 220. After the food 100 is placed, the lower pot 220 is horizontally moved to return to the state of the container unit 20J. In this case, in order to close the openings 210B and 220B of the container unit 20, the food 100 must be a size that is completely accommodated in the lower pot 220 or a size that is slightly exposed from the second opening 220B of the lower pot 220. Assuming that the food 100 is of such a size that it is largely exposed from the second opening 220B of the lower pot 220 as in the container unit 20L, if the lower pot 220B is moved horizontally, the food 100 collides with the upper pot 210, and thus the openings 210B and 220B of the container unit 20 cannot be closed. Therefore, the maximum size of the food 100 that can be placed in the container unit 20 is limited to a size corresponding to the internal space of the lower pot 220, so that the openings 210B and 220B of the container unit 20 can be closed. Therefore, the food storage space S, which is the internal space of the lower pot 220, is a space of a size corresponding to the maximum size of the food 100 that can be placed from the opening 220B and closed. As a result, the surplus space M located inside the upper pot 210 becomes a space where the food 100 cannot be placed due to the structure of the container unit 20.

[0144] In addition, in order to make the remaining space M a space where the food 100 cannot exist, it can be performed by other methods besides the method based on the mechanical structure of the container unit 20. For example, it can be controlled so that when the sensor detects that the food 100 of the same size as the food 100 exists in the remaining space M, the container unit 20 is not closed. In addition, it can be controlled so that when the sensor detects that the food 100 exists in the remaining space M in the state where the container unit 20 is closed, an error display is displayed on the output device 15, and heating and cooking are not performed, so that at least when the electromagnetic wave is radiated from the antenna 50, there is no food 100 in the remaining space M.

[0145] Fig.13 Another example of the movement of the object to be cooked is shown. In order to change the distance between the object to be cooked and the antenna 50, it is also possible to move the placement surface 250A parallel to the placement surface 250A without changing the distance between the placement surface 250A on which the object to be cooked is placed and the antenna 50. The movement may be a linear movement of the placement surface 250A or a rotation of the placement surface 250A. Fig.13 The rotation of the mounting surface 250A is illustrated. Fig.13In the embodiment, the placing surface 250A is provided to be rotatable by a rotating shaft 250E which is rotationally driven by a driving source (not shown). The rotation can be controlled by the controller 40. When the placing surface 250A rotates, the food to be cooked moves from the position 100A to the position 100B, for example. When the food to be cooked moves from the position 100A to the position 100B, the food to be cooked approaches the antenna 50.

[0146] In order to change the distance between the food to be cooked and the antenna 50, in addition to changing the distance between the placing surface 250A on which the food to be cooked is placed and the antenna 50, the placing surface 250A may be moved parallel to the surface. In addition, in order to change the distance between the food to be cooked and the antenna 50, the placing surface 250A may be moved parallel to the surface without changing the distance between the placing surface 250A on which the food to be cooked is placed and the antenna 50. In addition, the antenna 50 may be pre-arranged below the placing surface 250A, and the placing surface 250A may be moved up and down, thereby changing the distance between the food to be cooked and the antenna 50.

[0147] Fig.14 The results of an experiment in which the weight of the food to be cooked was changed to investigate the relationship between the distance between the antenna and the food to be cooked and the resonant frequency are shown. Figure 1 The container unit 20 shown in the figure. The frequency of the electromagnetic wave radiated from the antenna 50 is set to 915 MHz. The size and shape of the container unit 20 are set so that when there is no food to be cooked inside, its resonant frequency (self-resonant frequency) becomes close to the frequency of the electromagnetic wave radiated from the antenna 50, so that a resonant cavity can be obtained.

[0148] In the experiment, 100g, 200g, 300g, 400g, and 550g of frozen beef were used as the food to be cooked. For each weight of frozen beef, the distance between the antenna 50 and the frozen beef was changed, and the resonant frequency of the container unit 20 was measured. In addition, the resonant frequency was measured in a state where heating was hardly advanced.

[0149] like Fig.14 As shown, the resonant frequency is different depending on the weight of the frozen beef. Therefore, by adjusting at least one of the distance between the antenna 50 and the frozen beef and the volume adjustment of the container unit 20, it is possible to perform appropriate electromagnetic wave radiation according to the different weights of the cooked food. In particular, when the weight of the cooked food is large, such as 550g of frozen beef, if the distance is changed, the resonant frequency changes significantly, so for the heavy cooked food, the distance adjustment is more preferred. In addition, when the weight of the cooked food is small, such as 100g of frozen beef, even if the distance is changed, the change in the resonant frequency is small, so it is more preferred to adjust the volume of the container unit 20.

[0150] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0151] Description of Reference Numerals

[0152] 10Heating Cooker

[0153] 13 Shell

[0154] 13A front part

[0155] 13B Top

[0156] 13C back

[0157] 13D base

[0158] 15 Input and output devices

[0159] 17. Insulation Materials

[0160] 20 container units

[0161] 20A container unit

[0162] 20B container unit

[0163] 20C container unit

[0164] 20D container unit

[0165] 20E container unit

[0166] 20F container unit

[0167] 20G container unit

[0168] 20H container unit

[0169] 20J container unit

[0170] 20K container unit

[0171] 20L container unit

[0172] 30 High frequency circuit

[0173] 31 Amplifier

[0174] 33 Monitoring circuit

[0175] 40 Controllers

[0176] 50-day antenna

[0177] 60 Heater

[0178] 70 Temperature Sensor

[0179] 80 adjustment mechanism

[0180] 81 External organizations

[0181] 82 Internal Organization

[0182] 90 drive unit

[0183] 100 Foods to be cooked

[0184] 100A Cooking

[0185] 100B Food to be cooked

[0186] 200 chambers

[0187] 210 1st segment

[0188] 210A Partial Chamber 1

[0189] 210B Opening 1

[0190] 210D upper surface

[0191] 210E wall

[0192] 210F expansion part

[0193] 210G 1st contact surface

[0194] 210H shielding material

[0195] 220 Second Split

[0196] 220A Second partial chamber

[0197] 220B 2nd opening

[0198] 220D lower surface

[0199] 220E wall

[0200] 221 Main Body

[0201] 222 inner cylinder part

[0202] 222A outer cylinder part

[0203] 223 cone

[0204] 223A Second contact surface

[0205] 224 clamped part

[0206] 225 Sliding part

[0207] 226 barrel

[0208] 227 bottom

[0209] 228 through hole

[0210] 229 Contact Department

[0211] 230 Space

[0212] 250 inner container

[0213] 250A loading surface

[0214] 250B bottom

[0215] 250C SIDEWALL

[0216] 250D snap fit

[0217] 250E Rotating Axis

[0218] 300 Second split unit

[0219] 300A 2nd split unit

[0220] 300B 2nd split unit

[0221] 310 unit housing

[0222] 311 stopper

[0223] 810 1st axis

[0224] 811 lifting unit

[0225] 812 2nd axis

[0226] 813 upper lifting body

[0227] 814 lower lifting body

[0228] 815 2nd operating arm

[0229] 816 Spring

[0230] 820 operating body

[0231] 821 insertion body

[0232] 823 operating head

[0233] 825 No.1 operating arm

[0234] 827 Spring

[0235] D1 distance

[0236] D2 distance

[0237] D3 distance

[0238] E-Electromagnetic waves

[0239] H1 Height

[0240] H2 Height

[0241] M margin space

[0242] S is a storage space for food to be cooked.

Claims

1. A heating cooker, characterized in that: have: A container unit for storing food to be cooked; The antenna radiates the high frequency supplied from the high frequency circuit outputting the high frequency into the container unit as electromagnetic waves for heating the food to be cooked; as well as a placing surface for placing the food to be cooked, The container unit is configured to form a resonant cavity that resonates with the electromagnetic wave radiated from the antenna, The cooking device is configured to be capable of changing a first distance between the antenna and the food placed on the placement surface.

2. The heating cooker according to claim 1, characterized in that The cooking food storage space for storing the cooking food placed on the placement surface is arranged in the container unit so as to exist between the antenna and the placement surface.

3. The heating cooker according to claim 1, characterized in that The antenna is arranged above the placement surface in the container unit. The placement surface is provided in the container unit so as to be movable in the up-down direction.

4. The heating cooker according to claim 1, characterized in that The cooking device further includes a controller that monitors an operating state of the high-frequency circuit during radiation of the electromagnetic wave and controls a size of the first distance according to the operating state.

5. The heating cooker according to claim 4, characterized in that: The mounting surface is located at a first position as an initial position before the electromagnetic wave is radiated. The controller is configured to move the placement surface from the first position to the second position according to the operation state during the radiation of the electromagnetic wave. The second position is a position where the first distance is smaller than when the placement surface is at the first position.

6. The heating cooker according to claim 5, characterized in that: The placement surface is configured to be movable within the container unit so as to change a second distance between the placement surface and the antenna. The first position is a position where the second distance is maximum.

7. The heating cooker according to claim 5, characterized in that The container unit has a residual space between a cooking storage space for storing the cooking placed on the placing surface and the antenna, where the cooking is not present when the placing surface is at the first position. The margin space is a space in which the food to be cooked can be placed when the placement surface moves to the second position.

8. The heating cooker according to claim 1, characterized in that: The container unit is configured such that a volume of the container unit is variable.

9. The heating cooker according to claim 8, characterized in that The cooking device further includes a controller configured to monitor an operating state of the high-frequency circuit during radiation of the electromagnetic wave and adjust the volume according to the operating state.

10. The heating cooker according to claim 8, characterized in that The cooking device further includes a controller that monitors an operating state of the high-frequency circuit during radiation of the electromagnetic wave, and controls a magnitude of the first distance and adjusts the volume according to the operating state.

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