Electromagnetic wave heating device

Abstract

An electromagnetic wave heating device (100) comprises: a housing (1) having conductivity; an electromagnetic wave generation unit (10) that generates an electromagnetic wave, which is a linearly polarized wave; a plurality of radiation units (3) that radiate the electromagnetic wave generated by the electromagnetic wave generation unit to the inside of the housing; a directivity control unit (2) that controls directivity of the electromagnetic wave radiated from the plurality of radiation units; and an electromagnetic wave absorption unit (5) that is disposed inside the housing so as to align with an oscillation plane of the electromagnetic wave and absorbs the electromagnetic wave inside the housing.

Description

Electromagnetic heating device

[0001] The present disclosure relates to an electromagnetic wave heating device.

[0002] Conventionally, a microwave heating device has been disclosed that controls the radiation direction of microwaves from multiple antennas installed on the same surface in order to create a temperature difference between a heating object, which is the object to be heated, and a non-heating object, which is not the object to be heated (see non-patent document 1).

[0003] Yang Yang, Zhipeng Fan, Tao Hong, Maoshun Chen, Xiangwei Tang, Jianbo He, Xing Chen, Changjun Liu, Huacheng Zhu, and Kama Huang, Design of Microwave Directional Heating System Based on Phased-Array Antenna, IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 68, NO. 11, NOVEMBER 2020, p. 4896-4904.

[0004] However, the electromagnetic wave heating device described in Non-Patent Document 1 has the problem that the electromagnetic waves are repeatedly reflected on the inner surface of the metal casing, causing the reflected electromagnetic waves to heat not only the object to be heated but also the object not to be heated, making it difficult to create a sufficient temperature difference between the object to be heated and the object not to be heated.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide an electromagnetic wave heating device that can generate a higher temperature difference between an object to be heated and an object not to be heated than conventionally.

[0006] The electromagnetic wave heating device according to the present disclosure is characterized by comprising a conductive housing, an electromagnetic wave generating unit that generates linearly polarized electromagnetic waves, a plurality of radiating units that radiate the electromagnetic waves generated by the electromagnetic wave generating unit into the housing, a directivity control unit that controls the directionality of the electromagnetic waves from the plurality of radiating units, and an electromagnetic wave absorbing unit that is arranged inside the housing along the vibration plane of the electromagnetic waves and absorbs the electromagnetic waves inside the housing.

[0007] According to the present disclosure, an electromagnetic wave absorbing section is provided that absorbs electromagnetic waves along the vibration plane of the electromagnetic waves with controlled directionality, thereby suppressing the reflection of electromagnetic waves on the inner surface of the housing and creating a greater temperature difference between the heated object and the non-heated object than before.

[0008] FIG. 1 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device according to embodiment 1. FIG. 2 is a diagram showing simulation results of electric field distribution inside a housing of an electromagnetic wave heating device according to embodiment 1. FIG. 3 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device according to embodiment 2. FIG. 4 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device according to embodiment 3. FIG. 5 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device according to embodiment 4. FIG. 6 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device according to embodiment 6. FIG. 7 is a cross-sectional view schematically showing an electromagnetic wave absorbing section of an electromagnetic wave heating device according to embodiment 6.

[0009] Embodiments of the present disclosure will be described in detail below with reference to the drawings. Embodiment 1. First, a schematic configuration of an electromagnetic wave heating device 100 according to embodiment 1 will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view schematically illustrating the configuration of the electromagnetic wave heating device 100 according to embodiment 1. The electromagnetic wave heating device 100 according to embodiment 1 is a cooking microwave oven, a microwave heating device, or other electromagnetic wave heating device, and is a device for heating an object 6 to be heated by irradiating the object 6 with electromagnetic waves. As shown in FIG. 1, the electromagnetic wave heating device 100 includes a conductive housing 1, an electromagnetic wave generating unit 10 that generates electromagnetic waves, a plurality of phase control units 2 that control the phases of the electromagnetic waves generated by the electromagnetic wave generating unit 10, a plurality of antennas 3 that radiate the electromagnetic waves, the phases of which are controlled by the phase control units 2, into a space S1 inside the housing 1, and an electromagnetic wave absorbing unit 5 that absorbs a portion of the electromagnetic waves radiated into the space S1.

[0010] The housing 1 is formed in a box shape from a conductive material, and defines a space S1 inside as a heating chamber. By being formed from a conductive material, the housing 1 prevents electromagnetic waves radiated inside from leaking to the outside. For example, the housing 1 is formed in a rectangular parallelepiped shape from carbon steel, special steel, or other alloy. The electromagnetic wave generator 10 generates linearly polarized electromagnetic waves and distributes the generated electromagnetic waves to multiple phase controllers 2. For example, the electromagnetic wave generator 10 is formed from a magnetron and generates linearly polarized microwaves.

[0011] The phase control unit 2 controls the phase of the electromagnetic waves generated by the electromagnetic wave generation unit 10, thereby controlling the directivity of the electromagnetic waves by superposing the electromagnetic waves radiated into the space S1 from the multiple antennas 3. In other words, the multiple phase control units 2 control the directivity of the electromagnetic waves from the multiple antennas 3 serving as a multi-element antenna. For example, the phase control unit 2 is configured by an electronic circuit or the like that functions as a phase shifter.

[0012] For example, the multiple phase control units 2 control the directivity of the electromagnetic waves from the multiple antennas 3 so that the direction of the electromagnetic waves from the multiple antennas 3 is 4a direction (propagation direction, Z direction) shown in Fig. 1. In the first embodiment, the polarization planes (planes of vibration of polarized waves) of the electromagnetic waves from the multiple antennas 3 are along the 4a direction and the 4b direction (polarization direction, X direction) shown in Fig. 1. In the first embodiment, the multiple phase control units 2 constitute a directivity control unit that controls the directivity of the electromagnetic waves from the multiple antennas 3.

[0013] The antennas 3 are arranged, for example, on the inner upper surface of the rectangular parallelepiped housing 1 so as to be lined up along the inner upper surface, and radiate electromagnetic waves downward in the direction 4a. In the first embodiment, the antennas 3 constitute a plurality of radiating units that radiate the electromagnetic waves generated by the electromagnetic wave generating unit 10 into the housing 1.

[0014] The electromagnetic wave absorbing unit 5 is disposed inside the housing 1 along the vibration plane of the electromagnetic waves from the multiple antennas 3, and absorbs the electromagnetic waves by converting a portion of the incident electromagnetic waves into thermal energy. For example, the electromagnetic wave absorbing unit 5 is made of a synthetic resin having magnetic material powder kneaded into it. Furthermore, for example, the electromagnetic wave absorbing unit 5 is formed in a plate or sheet shape and is disposed so as to be in contact with or close to the inner surface of the housing 1. Furthermore, for example, the electromagnetic wave absorbing unit 5 is disposed so as to cover substantially the entire interior surface of the rectangular parallelepiped housing 1. It is desirable that the electromagnetic wave absorbing unit 5 be disposed so as to be in close contact with the inner surface of the housing 1. Furthermore, the electromagnetic wave absorbing unit 5 is not limited to being disposed so as to be in direct contact with the inner surface of the housing 1, but may also be disposed so as to be in indirect contact via, for example, a heat conductive sheet, heat conductive grease, adhesive, or the like.

[0015] Furthermore, the electromagnetic wave absorbing portion 5 is arranged so that at least a portion of its surface on the center side of the space S1 is aligned with the polarization plane. In other words, the electromagnetic wave absorbing portion 5 is arranged so that at least a portion of its surface on the center side of the space S1 is substantially parallel to the 4a direction and the 4b direction. It is desirable that the electromagnetic wave absorbing portion 5 be formed in a flat plate shape and arranged so that substantially the entire surface on the center side of the space S1 extends in a direction along the polarization plane. By being arranged in this manner, the electromagnetic wave absorbing portion 5 suppresses absorption of electromagnetic waves propagating in the 4a direction and facilitates absorption of electromagnetic waves propagating in a direction intersecting the 4a direction in the space S1.

[0016] Generally, in an electromagnetic wave heating device such as a microwave oven, electromagnetic waves are radiated from an antenna into the inside of the electromagnetic wave heating device, and the radiated electromagnetic waves are repeatedly reflected by the inner surface of a metal housing, causing them to behave as standing waves inside the electromagnetic wave heating device. Therefore, even if an attempt is made to selectively heat multiple regions inside the electromagnetic wave heating device by controlling the directionality of the electromagnetic waves, it is difficult to create a sufficient temperature difference between the object to be heated in the heating region that is the target of heating and the object to be unheated in the non-heating region that is not the target of heating, due to the influence of the standing waves caused by the reflected waves on the inner surface of the housing.

[0017] In contrast, the electromagnetic wave heating device 100 according to the first embodiment makes it easier for the electromagnetic wave absorbing section 5 to absorb reflected waves that are generated when electromagnetic waves radiated from the multiple antennas 3 are reflected on the inner surface of the housing 1, thereby suppressing the generation of standing waves in the space S1 and making it possible to generate a higher temperature difference between the object to be heated and the object to be unheated than in the past. In other words, the electromagnetic wave heating device 100 according to the first embodiment makes it easier for the electromagnetic wave absorbing section 5 to absorb electromagnetic waves in a direction that intersects the vibration plane of the electromagnetic waves from the multiple antennas 3, thereby suppressing the generation of standing waves in the space S1 and making it possible to generate a higher temperature difference between the object to be heated and the object to be unheated than in the past.

[0018] 2 is a diagram showing the results of a simulation of the electric field distribution inside the housing of the electromagnetic wave heating device 100 according to embodiment 1. Specifically, this diagram shows the results of a simulation of the electric field distribution inside the housing of the electromagnetic wave heating device 100 according to embodiment 1, when the electromagnetic field control surface 8 shown in FIG. 1 is viewed from the direction 4a shown in FIG. 1. As shown in FIG. 2, the electromagnetic wave heating device 100 controls the directivity of the electromagnetic waves from the multiple antennas 3 so that the electromagnetic waves from the multiple antennas 3 are directed toward the center of the electromagnetic field control surface 8, thereby increasing the electric field strength of the heating region in the central portion, and suppressing the electromagnetic waves from the multiple antennas 3 from being reflected by the inner surface of the housing 1 and behaving as standing waves in the space S1, thereby suppressing the electric field strength in other portions other than the central portion.

[0019] As described above, the electromagnetic wave heating device 100 according to the first embodiment includes a conductive housing 1, an electromagnetic wave generating unit 10 that generates linearly polarized electromagnetic waves, a plurality of antennas 3 that radiate the electromagnetic waves generated by the electromagnetic wave generating unit 10 into the interior of the housing 1, a phase control unit 2 that controls the directivity of the electromagnetic waves from the plurality of antennas 3, and an electromagnetic wave absorbing unit 5 that is arranged inside the housing 1 along the vibration plane of the electromagnetic waves and absorbs the electromagnetic waves inside the housing 1. As configured in this way, the electromagnetic wave heating device 100 according to the first embodiment includes the electromagnetic wave absorbing unit 5 that absorbs the electromagnetic waves along the vibration plane of the electromagnetic waves whose directivity is controlled, thereby suppressing the reflection of the electromagnetic waves on the inner surface of the housing 1 and creating a strength and weakness in the electric field distribution in the space S1, thereby making it possible to generate a higher temperature difference between the heated object 6 and the non-heated object 7 than before.

[0020] Furthermore, the electromagnetic wave heating device 100 according to the first embodiment includes an electromagnetic wave absorbing section 5 that is arranged so as to be in contact with or in close proximity to the inner surface of the housing 1. As a result, the electromagnetic wave heating device 100 according to the first embodiment suppresses reflection of electromagnetic waves between the electromagnetic wave absorbing section 5 and the inner surface of the housing 1, and also makes it easier for heat generated in the electromagnetic wave absorbing section 5 to be transferred to the housing 1, thereby suppressing a temperature rise in the electromagnetic wave absorbing section 5 and suppressing heating of the non-heated object 7 due to radiation from the electromagnetic wave absorbing section 5.

[0021] The electromagnetic wave heating device 100 according to the first embodiment is configured to distribute the electromagnetic waves generated by the electromagnetic wave generating unit 10 to a plurality of phase control units 2 and control the phases of the plurality of electromagnetic waves by the plurality of phase control units 2, but is not limited to this. The electromagnetic wave heating device only needs to be configured to control the directivity of the electromagnetic waves radiated from a plurality of antennas, and may be configured, for example, to provide an electromagnetic wave generating unit for each of the plurality of antennas and control the timing of generation of the electromagnetic waves for each of these electromagnetic wave generating units.

[0022] Embodiment 2 Next, an electromagnetic wave heating device 200 according to embodiment 2 will be described with reference to Fig. 3. The electromagnetic wave heating device 200 according to embodiment 2 differs from the electromagnetic wave heating device 100 according to embodiment 1 in that it is provided with a heat dissipation section 9, but other configurations are similar, and the same components as those in embodiment 1 will be assigned the same reference numerals and descriptions thereof will be omitted.

[0023] Fig. 3 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device 200 according to embodiment 2. As shown in Fig. 3, the electromagnetic wave heating device 200 includes a housing 1, an electromagnetic wave generating unit 10, a plurality of phase control units 2, a plurality of antennas 3, an electromagnetic wave absorbing unit 5 that absorbs a portion of the electromagnetic waves radiated into space S1, and a heat dissipating unit 9 that dissipates heat generated in the electromagnetic wave absorbing unit 5 to the outside of the housing 1.

[0024] For example, the heat dissipation unit 9 as a dissipation unit is arranged so as to be exposed to the outside of the housing 1, with one of the faces of the housing 1 sandwiched between the heat dissipation unit 9 and the electromagnetic wave absorption unit 5, and heat generated in the electromagnetic wave absorption unit 5 is transferred via the housing 1 to dissipate to the outside of the housing 1. For example, the heat dissipation unit 9 is arranged so as to overlap with the electromagnetic wave absorption unit 5 when viewed from a direction perpendicular to the face of the housing 1 on which the electromagnetic wave absorption unit 5 is arranged (for example, the Y direction shown in FIG. 3 ), and is formed so as to be approximately the same size as the electromagnetic wave absorption unit 5 when viewed from that direction.

[0025] Furthermore, for example, the heat dissipation unit 9 is arranged so as to be in contact with or close to the outer surface of the housing 1. It is desirable that the heat dissipation unit 9 is arranged so as to be in close contact with the outer surface of the housing 1. Furthermore, the heat dissipation unit 9 is not limited to being arranged so as to be in direct contact with the inner surface of the housing 1, and may be arranged so as to be in indirect contact via, for example, a heat conductive sheet, heat conductive grease, adhesive, etc. Furthermore, the electromagnetic wave heating device 200 may be provided with a fan arranged outside the housing 1 for dissipating heat from the heat dissipation unit 9 into the outside air.

[0026] By arranging the electromagnetic wave absorbing section 5 and the heat dissipation section 9 in this manner, the electromagnetic wave heating device 200 makes it easier for the heat generated in the electromagnetic wave absorbing section 5 to be transferred to the heat dissipation section 9, thereby suppressing the temperature rise of the electromagnetic wave absorbing section 5, suppressing the heating of the non-heated object 7 due to radiation from the electromagnetic wave absorbing section 5, and being able to handle heating for longer periods of time than the electromagnetic wave heating device 100 of embodiment 1.

[0027] Embodiment 3 Next, an electromagnetic wave heating device 300 according to embodiment 3 will be described with reference to Fig. 4. The electromagnetic wave heating device 300 according to embodiment 3 differs from the electromagnetic wave heating device 100 according to embodiment 1 in the configuration relating to the electromagnetic wave absorbing section, but the other configurations are similar, and the same components as those in embodiment 1 are denoted by the same reference numerals and description thereof will be omitted.

[0028] Fig. 4 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device 300 according to embodiment 3. As shown in Fig. 4, the electromagnetic wave heating device 300 includes a housing 1, an electromagnetic wave generating unit 10, a plurality of phase control units 2, a plurality of antennas 3, and a plurality of electromagnetic wave absorbing units 5 that absorb a portion of the electromagnetic waves radiated into a space S1.

[0029] For example, the electromagnetic wave heating device 300 includes a pair of electromagnetic wave absorbing units 5, one of which is arranged so that at least a portion of its surface on the center side of the space S1 is aligned along the plane of polarization, and the other is arranged at a distance from the other so that at least a portion of its surface on the center side of the space S1 is aligned along the plane of polarization and faces the one electromagnetic wave absorbing unit 5. Furthermore, for example, the electromagnetic wave heating device 300 includes a pair of electromagnetic wave absorbing units 5 formed in flat plates and arranged opposite each other along the plane of polarization, one of which is arranged in contact with or close to one of the inner surfaces of a box-shaped housing 1, and the other is arranged in contact with or close to the inner surface of the housing 1 that faces the one of the inner surfaces. In other words, the electromagnetic wave heating device 300 includes a pair of electromagnetic wave absorbing units 5 formed in flat plates and arranged in contact with or close to the inner surfaces of the housing 1 so that they are parallel to each other and aligned along the plane of polarization. As with the electromagnetic wave heating device 100 according to embodiment 1, in the electromagnetic wave heating device 300 according to embodiment 3, it is desirable that the plurality of electromagnetic wave absorbing units 5 are arranged so as to be in close contact with the inner surface of the housing 1. In embodiment 3, one electromagnetic wave absorbing unit 5 constitutes a first electromagnetic wave absorbing unit, and the other electromagnetic wave absorbing unit 5 constitutes a second electromagnetic wave absorbing unit.

[0030] As described above, the electromagnetic wave heating device 300 according to the third embodiment is provided with a pair of electromagnetic wave absorbing parts 5 that are arranged facing each other so as to be in contact with or in close proximity to the inner surface of the housing 1. As a result, the electromagnetic wave heating device 300 according to the third embodiment further suppresses reflection of electromagnetic waves on the inner surface of the housing 1 compared to the electromagnetic wave heating device 100 according to the first embodiment, and also makes it easier for heat generated in the electromagnetic wave absorbing parts 5 to be transferred to the housing 1, thereby suppressing a temperature rise in the electromagnetic wave absorbing parts 5 and suppressing heating of the non-heated object 7 due to radiation from the electromagnetic wave absorbing parts 5.

[0031] In addition, in embodiment 3, the electromagnetic wave heating device may be provided with one or more heat dissipation units, similar to the electromagnetic wave heating device 200 according to embodiment 2. Furthermore, the electromagnetic wave heating device is not limited to one provided with a pair of electromagnetic wave absorption units 5, but may be provided with three or more electromagnetic wave absorption units 5. For example, when the housing is formed in a rectangular parallelepiped shape, the electromagnetic wave heating device may be provided with electromagnetic wave absorption units 5 on all inner surfaces of the housing arranged along direction 4a, or may be provided with electromagnetic wave absorption units 5 on all inner surfaces including those other than the inner surfaces arranged along direction 4a. Furthermore, these multiple electromagnetic wave absorption units 5 may be formed integrally.

[0032] Embodiment 4 Next, an electromagnetic wave heating device 400 according to embodiment 4 will be described with reference to Fig. 5. The electromagnetic wave heating device 400 according to embodiment 4 differs from the electromagnetic wave heating device 100 according to embodiment 1 in the configuration relating to the electromagnetic wave absorbing section, but the other configurations are similar, and the same components as those in embodiment 1 are denoted by the same reference numerals and description thereof will be omitted.

[0033] Fig. 5 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device 400 according to embodiment 4. As shown in Fig. 5, the electromagnetic wave heating device 400 includes a housing 1, an electromagnetic wave generating unit 10, a plurality of phase control units 2, a plurality of antennas 3, and a plurality of electromagnetic wave absorbing units 5 that absorb a portion of the electromagnetic waves radiated into a space S1.

[0034] For example, the electromagnetic wave heating device 400 includes, in addition to the electromagnetic wave heating device 300 according to embodiment 3, an electromagnetic wave absorbing unit 5 arranged so as to be in contact with or close to the inner surface of the housing 1 arranged so as to intersect with direction 4a and along direction 4b. In other words, the electromagnetic wave heating device 400 includes an electromagnetic wave absorbing unit 5 arranged so as to intersect with the propagation direction of the electromagnetic waves. Furthermore, for example, the electromagnetic wave absorbing unit 5 arranged so as to intersect with the propagation direction of the electromagnetic waves is arranged so as to cover substantially the entire inner surface of the housing 1 arranged so as to intersect with the propagation direction of the electromagnetic waves. Note that it is also desirable that these multiple electromagnetic wave absorbing units 5 according to embodiment 4 are arranged so as to be in close contact with the inner surface of the housing 1. Furthermore, these multiple electromagnetic wave absorbing units 5 may be formed integrally.

[0035] As described above, the electromagnetic wave heating device 400 according to the fourth embodiment includes a pair of electromagnetic wave absorbing units 5 arranged opposite to each other so as to be in contact with or in close proximity to the inner surface of the housing 1, and an electromagnetic wave absorbing unit 5 arranged so as to intersect with the propagation direction of the electromagnetic waves. As a result, the electromagnetic wave heating device 400 according to the fourth embodiment further suppresses reflection of electromagnetic waves on the inner surface of the housing 1 compared to the electromagnetic wave heating device 100 according to the first embodiment, and also makes it easier for heat generated in the electromagnetic wave absorbing units 5 to be transferred to the housing 1, thereby suppressing a temperature rise in the electromagnetic wave absorbing units 5 and suppressing heating of the non-heated object 7 due to radiation from the electromagnetic wave absorbing units 5.

[0036] Embodiment 5 Next, an electromagnetic wave heating device 500 according to embodiment 5 will be described with reference to Fig. 6. The electromagnetic wave heating device 500 according to embodiment 5 differs from the electromagnetic wave heating device 100 according to embodiment 1 in the configuration relating to the electromagnetic wave absorbing section, but the other configurations are similar, and the same components as those in embodiment 1 are denoted by the same reference numerals and will not be described again.

[0037] FIG. 6 is a cross-sectional view schematically illustrating the configuration of an electromagnetic wave heating device 500 according to a fifth embodiment. As shown in FIG. 6 , the electromagnetic wave heating device 500 includes a housing 1, an electromagnetic wave generating unit 10, multiple phase control units 2, multiple antennas 3, and an electromagnetic wave absorbing unit 51 that absorbs a portion of the electromagnetic waves radiated into a space S1. The electromagnetic wave absorbing unit 51 is disposed inside the housing 1 along the vibration plane of the electromagnetic waves from the multiple antennas 3, and absorbs the electromagnetic waves by converting a portion of the incident electromagnetic waves into thermal energy. For example, the electromagnetic wave absorbing unit 51 is disposed so as to be in contact with or close to the inner surface of the housing 1. It is preferable that the electromagnetic wave absorbing unit 51 be disposed so as to be in close contact with the inner surface of the housing 1. Furthermore, the electromagnetic wave absorbing unit 51 is not limited to being disposed so as to be in direct contact with the inner surface of the housing 1, but may also be disposed so as to be in indirect contact with the inner surface of the housing 1 via, for example, a heat conductive sheet, heat conductive grease, adhesive, or the like.

[0038] The electromagnetic wave absorbing unit 51 includes a container 51a that forms a closed space therein and a liquid 51b sealed inside the container 51a. For example, the container 51a is made of a non-metallic material that easily transmits electromagnetic waves. Furthermore, for example, the liquid 51b is made of a liquid that contains water. It is desirable that the liquid 51b be a liquid whose main component is water or made entirely of water. However, any liquid may be used as long as it can absorb electromagnetic waves by converting a portion of the incident electromagnetic waves into thermal energy.

[0039] When electromagnetic waves are incident on the electromagnetic wave absorbing portion 51, the liquid 51b is heated, and convection of the liquid 51b occurs within the container 51a. As a result, the electromagnetic wave absorbing portion 51 easily transfers the heat of the liquid 51b to a wide area of ​​the housing 1 by heat exchange via the liquid 51b, suppressing a temperature rise in the electromagnetic wave absorbing portion 51 and suppressing heating of the non-heated object 7 due to radiation from the electromagnetic wave absorbing portion 51.

[0040] 7 and 8, an electromagnetic wave heating device 600 according to embodiment 6 will be described. The electromagnetic wave heating device 600 according to embodiment 6 differs from the electromagnetic wave heating device 500 according to embodiment 5 in the configuration relating to the electromagnetic wave absorbing section, but the other configurations are similar, and the same components as those in embodiment 5 are denoted by the same reference numerals and description thereof will be omitted.

[0041] Fig. 7 is a cross-sectional view schematically showing the configuration of an electromagnetic wave heating device 600 according to embodiment 6, and Fig. 8 is a cross-sectional view schematically showing an electromagnetic wave absorbing section of the electromagnetic wave heating device 600 according to embodiment 6. As shown in Fig. 7, the electromagnetic wave heating device 600 includes a housing 1, an electromagnetic wave generating section 10, a plurality of phase control sections 2, a plurality of antennas 3, and electromagnetic wave absorbing sections 52 and 53 that absorb a portion of the electromagnetic waves radiated into the space S1.

[0042] The electromagnetic wave absorbing section 52 as an internal part is arranged inside the housing 1 so as to follow the vibration plane of the electromagnetic waves from the multiple antennas 3, and absorbs the electromagnetic waves by converting a portion of the incident electromagnetic waves into thermal energy. For example, the electromagnetic wave absorbing section 52 is arranged so as to be in contact with or close to the inner surface of the housing 1. It is desirable that the electromagnetic wave absorbing section 52 is arranged so as to be in close contact with the inner surface of the housing 1.

[0043] The electromagnetic wave absorbing portion 53 as the diverging portion and external portion is arranged so as to be exposed to the outside of the housing 1, with one of the surfaces of the housing 1 sandwiched between the electromagnetic wave absorbing portion 52 and the electromagnetic wave absorbing portion 52. For example, the electromagnetic wave absorbing portion 53 is arranged so as to at least partially overlap with the electromagnetic wave absorbing portion 52 when viewed from a direction perpendicular to the surface of the housing 1 on which the electromagnetic wave absorbing portion 52 is arranged (for example, the Y direction shown in FIG. 7). Also, for example, the electromagnetic wave absorbing portion 53 is arranged so as to be in contact with or close to the outer surface of the housing 1. Note that the electromagnetic wave absorbing portion 53 is preferably arranged so as to be in close contact with the outer surface of the housing 1. Furthermore, the electromagnetic wave absorbing portions 52, 53 are not limited to being arranged so as to be in direct contact with the inner and outer surfaces of the housing 1, but may be arranged so as to be in indirect contact via, for example, a thermally conductive sheet, thermally conductive grease, adhesive, or the like.

[0044] 8, the electromagnetic wave absorbing unit 52 has a container 52a forming a space therein and a liquid 51b sealed inside the container 52a, and the electromagnetic wave absorbing unit 53 has a container 53a forming a space therein and a liquid 51b sealed inside the container 53a, and the internal spaces of the containers 52a and 53a are connected to form a flat space by the containers 52a and 53a. Therefore, the liquid 51b sealed inside the container 52a and the liquid 51b sealed inside the container 52a can move between the interiors of the containers 52a and 53a.

[0045] For example, the flat space formed by the container 52a and the container 53a has a tubular space formed by multiple folds, and is configured to facilitate convection of the liquid 51b between the inside of the container 52a and the inside of the container 53a. With this configuration, the electromagnetic wave absorbing units 52, 53 heat the liquid 51b in the container 52a by the incident electromagnetic waves, and cool the liquid 51b in the container 53a outside the housing 1, thereby generating convection of the liquid 51b. Heat exchange via the liquid 51b enables the heat of the liquid 51b to be dissipated outside the housing 1. The electromagnetic wave heating device 600 may also include a fan disposed outside the housing 1 for dissipating the heat of the liquid 51b into the outside air. The electromagnetic wave heating device may also include multiple electromagnetic wave absorbing units 52, 53.

[0046] In addition, the present disclosure allows for free combination of the respective embodiments, modification of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments.

[0047] The electromagnetic wave heating device according to the present disclosure can be used, for example, as an electromagnetic wave heating device having a function of separately heating an object to be heated and an object not to be heated within the electromagnetic wave heating device.

[0048] 1 Housing, 2 Phase control unit, 3 Antenna, 5 Electromagnetic wave absorbing unit, 6 Heated object, 7 Non-heated object, 8 Electromagnetic field control surface, 9 Heat dissipation unit, 10 Electromagnetic wave generating unit, 51 Electromagnetic wave absorbing unit, 51a Container, 51b Liquid, 52 Electromagnetic wave absorbing unit, 52a Container, 53 Electromagnetic wave absorbing unit, 53a Container, 100 Electromagnetic wave heating device, 200 Electromagnetic wave heating device, 300 Electromagnetic wave heating device, 400 Electromagnetic wave heating device, 500 Electromagnetic wave heating device, 600 Electromagnetic wave heating device, S1 Space.

Claims

1. An electromagnetic wave heating device comprising: a conductive housing; an electromagnetic wave generating unit that generates linearly polarized electromagnetic waves; a plurality of radiating units that radiate the electromagnetic waves generated by the electromagnetic wave generating unit into the housing; a directivity control unit that controls the directivity of the electromagnetic waves from the plurality of radiating units; and an electromagnetic wave absorbing unit that is disposed inside the housing such that at least a portion of the electromagnetic waves is aligned along the vibration plane of the electromagnetic waves and that absorbs the electromagnetic waves inside the housing.

2. The electromagnetic wave heating device according to claim 1, characterized in that the electromagnetic wave absorbing section is arranged so as to be in contact with or in close proximity to the inner surface of the housing.

3. An electromagnetic wave heating device as described in claim 1 or 2, characterized in that it is provided with a dissipation section arranged so as to be exposed to the outside of the housing and dissipating heat from the electromagnetic wave absorption section to the outside of the housing.

4. An electromagnetic wave heating device according to any one of claims 1 to 3, characterized in that the electromagnetic wave absorbing section comprises a liquid that absorbs electromagnetic waves and a container that encloses the liquid.

5. The electromagnetic wave heating device according to claim 4, characterized in that the electromagnetic wave absorbing section dissipates heat from the electromagnetic wave absorbing section to the outside of the housing by heat exchange via the liquid.

6. The electromagnetic wave heating device described in claim 5, characterized in that the electromagnetic wave absorbing section has an inner portion arranged inside the housing and an outer portion arranged so as to be exposed to the outside of the housing, and the heat of the electromagnetic wave absorbing section is dissipated to the outside of the housing by convection of the liquid moving between the inner portion and the outer portion.

7. An electromagnetic wave heating device as described in any one of claims 1 to 6, characterized in that the electromagnetic wave absorbing section is a first electromagnetic wave absorbing section, and is provided with a second electromagnetic wave absorbing section that is arranged inside the housing at a distance from the first electromagnetic wave absorbing section and absorbs electromagnetic waves inside the housing.

8. An electromagnetic wave heating device according to any one of claims 1 to 6, characterized in that the electromagnetic wave absorbing section is arranged so as to cover the entire inner surface of the housing.

Images