JP2018045813A - Microwave heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave heating apparatus capable of partially heating only a part of an object to be heated when heating the object to be heated.SOLUTION: A microwave heating apparatus includes: a heating chamber 110 in which an object to be heated is placed; a first recess 111 and a second recess 112 provided in the heating chamber; a first antenna 131 put in the first recess; a second antenna 132 put in the second recess; a first microwave generation part 121 connected to the first antenna; a second microwave generation part 122 connected to the second antenna; and a control part 140 for controlling the first microwave generation part and the second microwave generation part. The first recess reflects microwaves radiated by the first antenna, and the second recess reflects the microwaves radiated by the second antenna.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a microwave heating apparatus.

  A microwave heating device heats an object to be heated by placing the object to be heated in a heating chamber, irradiating the object to be heated with microwaves generated by a microwave generation source, and absorbing the object. (For example, Patent Document 1). In such a microwave heating apparatus, the microwave radiated into the heating chamber is repeatedly reflected on the wall surface of the heating chamber and is irradiated to the object to be heated.

  Generally, a magnetron, which is a kind of vacuum tube, is used as a microwave generation device in a microwave heating device. However, by using a semiconductor element instead of a magnetron, the microwave heating device is reduced in size and weight. Output controllability can be improved. As such a semiconductor element, for example, a semiconductor element using gallium nitride or the like capable of flowing a large current with a high breakdown voltage even in a high frequency region can be given.

JP 2009-16149 A JP-A-10-172750 JP 2007-280971 A

  In the microwave heating apparatus, the object is usually to uniformly heat the object to be heated, but there are cases where it is desired to heat only a part of the object to be heated. For example, when a lunch box containing food, such as salad, rice, and meat, is heated, rice and meat are desired to be heated, but the salad is not desired to be heated. In this case, if the whole lunch box is heated uniformly in the microwave heating apparatus, the salad that is not desired to be heated will be heated.

  Therefore, there is a demand for a microwave heating apparatus that can partially heat a part to be heated when the object to be heated is heated.

  In one aspect, the microwave heating apparatus is placed in a heating chamber in which an object to be heated is placed, a first recess and a second recess provided in the heating chamber, and the first recess. Connected to the second antenna, a second antenna placed in the second recess, a first microwave generator connected to the first antenna, and the second antenna A second microwave generation unit, and a control unit that controls the first microwave generation unit and the second microwave generation unit, wherein the first recess includes the first microwave generation unit The microwave radiated from the antenna is reflected, and the second recess reflects the microwave radiated from the second antenna.

  As one aspect, when the object to be heated is heated in the microwave heating apparatus, a part of the object to be heated can be partially heated.

Structural drawing of microwave heating apparatus in the first embodiment Structure diagram of semiconductor device used for microwave heating device Structural diagram of Modification 1 of the microwave heating apparatus according to the first embodiment Explanatory drawing of the modification 2 of the microwave heating apparatus in 1st Embodiment. Explanatory drawing of the microwave generation part of the microwave heating device in 1st Embodiment Structure diagram of microwave heating apparatus in second embodiment Structural drawing of a modification of the microwave heating apparatus in the second embodiment

  The form for implementing is demonstrated below. In addition, about the same member etc., the same code | symbol is attached | subjected and description is abbreviate | omitted.

[First Embodiment]
A microwave heating apparatus according to the first embodiment will be described with reference to FIG. The microwave heating apparatus in this embodiment includes a heating chamber 110 in which an object to be heated 100 is placed, a first microwave generation unit 121, a second microwave generation unit 122, a first antenna 131, and a second antenna. 132, the control unit 140, and the like. The first antenna 131 is connected to the first microwave generator 121, the second antenna 132 is connected to the second microwave generator 122, and the first microwave generator 121 is connected. The second microwave generator 122 is connected to the controller 140. In the present embodiment, the frequency of the microwaves generated by the microwave generators such as the first microwave generator 121 and the second microwave generator 122 is 2.45 GHz.

  In the present embodiment, a first recess 111 and a second recess 112 are formed on the bottom surface 110 a of the heating chamber 110, and the first antenna 131 is placed in the first recess 111. The second antenna 132 is placed in the second recess 112.

  The first concave portion 111 and the second concave portion 112 are formed of a material such as a metal that reflects microwaves. Therefore, a part of the microwave radiated from the first antenna 131 is directly irradiated to the object to be heated 100, and the other part is reflected by the first recess 111 and irradiated to the object to be heated 100. The In addition, a part of the microwave radiated from the second antenna 132 is directly irradiated to the object to be heated 100, and another part is reflected by the second recess 112 and is irradiated to the object to be heated 100. The

  Accordingly, the first recess 111 that covers the first antenna 131 functions as a mirror that reflects microwaves, and the second recess 112 that covers the second antenna 132 serves as a mirror that reflects microwaves. It functions. Therefore, the 1st recessed part 111 and the 2nd recessed part 112 are microwave reflection parts which reflect a microwave.

  In the present embodiment, the object to be heated 100 is mounted on a mounting table 150 in the heating chamber 110. The mounting table 150 is formed of a dielectric material that transmits microwaves, and covers the first recess 111 and the second recess 112. The object to be heated 100 is such that the first region 101 of the object to be heated 100 is directly above the first antenna 131, and the second region 102 of the object to be heated 100 is directly above the second antenna 132. It is placed. In the present embodiment, the first antenna 131 is installed in the first recess 111 behind the bottom surface 110a, and the second antenna 132 is the second antenna behind the bottom surface 110a. Is installed in the recess 112. Therefore, the first antenna 131 is installed in a region surrounded by the first recess 111 and the mounting table 150, and the second antenna 132 is a region surrounded by the second recess 112 and the mounting table 150. Is installed.

  In the present embodiment, when only the first region 101 of the object to be heated 100 is heated and the second region 102 is not desired to be heated, the control unit 140 radiates microwaves from the first antenna 131. However, control is performed so that microwaves are not radiated from the second antenna 132. As a result, only the first region 101 can be heated without heating the second region 102 of the article to be heated 100. In addition, when only the second region 102 of the object to be heated 100 is heated and the first region 101 is not to be heated, the control unit 140 radiates microwaves from the second antenna 132. Control is performed so that microwaves are not radiated from one antenna 131. Thereby, only the 2nd area | region 102 can be heated, without heating the 1st area | region 101 of the to-be-heated material 100. FIG.

  Further, even when both the first region 101 and the second region 102 are heated in the object to be heated 100, the temperature and the second region in the first region 101 are not heated uniformly. There is a case where it is desired to heat so that the temperature at the temperature is different from that at. In such a case, the intensity of the microwave radiated from the first antenna 131 and the radiation from the second antenna 132 are controlled by the control unit 140 so that each region has a desired temperature. Microwaves with different microwave intensities are emitted.

  For example, the intensity of the microwave generated by the first microwave generator 121 is set higher than the intensity of the microwave generated by the second microwave generator 122. Thereby, the intensity of the microwave radiated from the first antenna 131 connected to the first microwave generator 121 is from the second antenna 132 connected to the second microwave generator 122. It becomes higher than the intensity of the emitted microwave. Therefore, the object to be heated 100 can be heated so that the first region 101 has a higher temperature than the second region 102. As described above, in the present embodiment, the first region 101 and the second region 102 of the object to be heated 100 can be heated to a desired temperature by the control of the control unit 140.

  In the present embodiment, the first antenna 131 is placed in the first recess 111, and the second antenna 132 is placed in the second recess 112. Therefore, the side surface 111a of the first recess 111 and the side surface 112a of the second recess 112 are present and separated between the first antenna 131 and the second antenna 132. Therefore, since the microwave radiated from the first antenna 131 is applied to the first region 101 of the object 100 to be heated, the first region 101 can be efficiently heated. Similarly, since the microwave radiated from the second antenna 132 is applied to the second region 102 of the object 100 to be heated, the second region 102 can be efficiently heated.

  By the way, when a plurality of antennas are provided, the microwave radiated from one antenna may be incident on the other antenna. In this case, the microwave generation unit connected to the other antenna is It may be destroyed. However, in the present embodiment, the side surface 111a of the first recess 111 and the side surface 111a of the second recess 112 are present and separated between the first antenna 131 and the second antenna 132. ing. Therefore, the microwave radiated from the first antenna 131 is reflected by the side surface 111a of the first recess 111, and therefore does not enter the second antenna 132. Further, the microwave radiated from the second antenna 132 is reflected by the side surface 112 a of the second recess 112, and therefore does not enter the first antenna 131. Therefore, the microwave generated from one antenna is not destroyed by the microwave generation unit connected to the other antenna.

  In the present embodiment, the first microwave generation unit 121 and the second microwave generation unit 122 use semiconductor elements to generate high-output microwaves. Specifically, a HEMT (High Electron Mobility Transistor) using a nitride semiconductor is used. The HEMT using a nitride semiconductor is formed by stacking a nitride semiconductor layer on a substrate 210 such as SiC as shown in FIG. That is, a buffer layer 211 made of AlN, GaN, or the like, an electron transit layer 212, and an electron supply layer 213 are sequentially stacked on the substrate 210. The electron transit layer 212 is made of GaN, and the electron supply layer 213 is made of AlGaN or InAlN. Thereby, in the electron transit layer 212, 2DEG (two dimensional electron gas) 212a is generated in the vicinity of the interface with the electron supply layer 213. The gate electrode 231, the source electrode 232, and the drain electrode 233 are formed on the electron supply layer 213.

  In the microwave heating apparatus in this embodiment, three or more antennas may be provided. Specifically, as shown in FIG. 3, a third recess 113 is formed on the bottom surface 110 a of the heating chamber 110, and the third antenna 133 is placed in the third recess 113. Yes. The third microwave generator 123 and the third antenna 133 may be connected, and the third microwave generator 123 may be connected to the controller 140.

  Since the third recess 113 is also formed of a material that reflects microwaves, a part of the microwave radiated from the third antenna 133 is directly irradiated to the object to be heated 100, and the other part is The object to be heated 100 is irradiated by being reflected by the third recess 113. Therefore, the third recess 113 covering the third antenna 133 functions as a mirror that reflects microwaves, and is a microwave reflection part.

  In the microwave heating apparatus shown in FIG. 3, the first region 101 of the object to be heated 100 is directly above the first antenna 131, the second region 102 is directly above the second antenna 132, and the third region Is placed so that the region 103 is directly above the third antenna 133. In this microwave heating apparatus, microwaves are radiated from an antenna immediately below a region to be heated among the first region 101, the second region 102, and the third region 103 of the article to be heated 100. Control is performed so that microwaves are not radiated from the antenna directly below the area that you do not want. Accordingly, in the article to be heated 100, only the desired region can be heated without heating the first region 101, the second region 102, and the third region 103 other than the desired region. The above control is performed by the control unit 140.

  Further, as shown in FIG. 4, the present embodiment may be one in which four or more antennas are provided and the antennas are two-dimensionally arranged. In this microwave heating apparatus, the heating chamber 110 is formed by a bottom surface 110a and a cover 110b. In FIG. 4A, the mounting table 150 is indicated by a dotted line, and in FIG. 4B, the mounting table 150 and the cover 110b of the heating chamber 110 are indicated by a dotted line.

  Specifically, as shown in FIG. 4, the microwave heating apparatus includes a first antenna 131, a second antenna 132, a third antenna 133, and a fourth antenna 134. Four antennas are arranged two-dimensionally. A first microwave generator 121 is connected to the first antenna 131, and a second microwave generator 122 is connected to the second antenna 132. A third microwave generator 123 is connected to the third antenna 133, and a fourth microwave generator 124 is connected to the fourth antenna 134. The first microwave generator 121, the second microwave generator 122, the third microwave generator 123, and the fourth microwave generator 124 are connected to the controller 140.

  In such a microwave heating apparatus, only the region to be heated is heated without heating the region that is not to be heated among the four divided regions of the article to be heated 100 placed on the mounting table 150. be able to.

  Further, as shown in FIG. 5, the microwave generation unit in the present embodiment is configured such that the first microwave generation unit 121, the second microwave generation unit 122, and the third microwave generation unit 123 are DC. The power supply 170 may be connected. Although FIG. 5 shows a case where three antennas are provided as an example, the number of antennas may be plural. In this microwave generator, the microwave is generated by switching the semiconductor elements in the first microwave generator 121, the second microwave generator 122, and the third microwave generator 123 based on the control of the controller 140. Can be generated.

[Second Embodiment]
Next, a second embodiment will be described. In the microwave heating apparatus in this embodiment, as shown in FIG. 6, microwaves radiated from one antenna are incident on the other antenna between the first antenna 131 and the second antenna 132. In this case, the partition wall 261 is provided.

  In the microwave heating apparatus in this embodiment, a recess 115 is formed in the bottom surface 110 a of the heating chamber 110, and the first antenna 131 and the second antenna 132 are placed in the recess 115. In addition, inside the recess 115, a partition wall portion 261 is provided between the first antenna 131 and the second antenna 132, and the first antenna 131 and the second antenna 132 are separated from each other. Yes.

  Since the partition wall portion 261 is formed of a material that reflects microwaves, the microwave radiated from one antenna does not enter the other antenna, and the microwave radiated from the other antenna does not enter. It does not enter one antenna. Therefore, in this embodiment mode, the first region 101 and the second region 102 in the object to be heated 100 can be selected and heated, and the other antenna can be heated by the microwave radiated from the one antenna. The microwave generation part connected to is not destroyed.

  In this embodiment, as shown in FIG. 7, three or more antennas may be provided. In this case, the third antenna 133 is placed in the recess 115 provided in the bottom surface 110a of the heating chamber 110, and a partition wall portion 262 is provided between the second antenna 132 and the third antenna 133. ing. The partition wall portion 262 has a function similar to that of the partition wall portion 261.

  About contents other than the above, it is the same as that of 1st Embodiment.

  Although the embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes can be made within the scope described in the claims.

In addition to the above description, the following additional notes are disclosed.
(Appendix 1)
A heating chamber in which an object to be heated is placed;
A first recess and a second recess provided in the heating chamber;
A first antenna placed in the first recess;
A second antenna placed in the second recess;
A first microwave generator connected to the first antenna;
A second microwave generator connected to the second antenna;
A control unit for controlling the first microwave generation unit and the second microwave generation unit;
Have
The first recess reflects the microwave radiated from the first antenna;
The microwave heating apparatus, wherein the second recess reflects the microwave radiated from the second antenna.
(Appendix 2)
A mounting table formed of a dielectric covering the first recess and the second recess is provided;
The microwave heating apparatus according to appendix 1, wherein the object to be heated is placed on the mounting table.
(Appendix 3)
A heating chamber in which an object to be heated is placed;
A first antenna and a second antenna provided in the heating chamber;
A first microwave generator connected to the first antenna;
A second microwave generator connected to the second antenna;
A control unit for controlling the first microwave generation unit and the second microwave generation unit;
A partition formed by a material that reflects microwaves provided between the first antenna and the second antenna;
A microwave heating apparatus comprising:
(Appendix 4)
The first antenna and the second antenna are placed in a recess provided in the heating chamber,
The microwave heating apparatus according to appendix 3, wherein the partition wall is provided between the first antenna and the second antenna in the recess.
(Appendix 5)
The heated object is placed at a position immediately above the first antenna and the second antenna,
When heating the first region of the object to be heated, the control unit generates microwaves from the first microwave generation unit, radiates microwaves from the first antenna, and Heating the first region of the object to be heated;
When heating the second region of the object to be heated, microwaves are generated from the second microwave generator, microwaves are emitted from the second antenna, and the second region of the object to be heated is emitted. The microwave heating apparatus according to any one of appendices 1 to 4, wherein the region 2 is heated.
(Appendix 6)
6. The microwave heating apparatus according to appendix 4 or 5, wherein the first microwave generator and the second microwave generator include a semiconductor element formed of a nitride semiconductor.
(Appendix 7)
A direct current power source is connected to the first microwave generation unit and the second microwave generation unit, and the semiconductor element in the first microwave generation unit and the second microwave generation unit The microwave heating apparatus according to appendix 6, wherein microwaves are generated by switching between the two.
(Appendix 8)
A heating chamber in which an object to be heated is placed;
A first antenna and a second antenna provided in the heating chamber;
A first microwave generator connected to the first antenna;
A second microwave generator connected to the second antenna;
A microwave heating apparatus comprising:

100 heated object 101 first region 102 second region 110 heating chamber 111 first recess 112 second recess 115 recess 121 121 first microwave generator 122 second microwave generator 131 first antenna 132 Second antenna 140 Control unit 150 Mounting table 170 DC power supply 261 Partition

Claims (5)

A heating chamber in which an object to be heated is placed;
A first recess and a second recess provided in the heating chamber;
A first antenna placed in the first recess;
A second antenna placed in the second recess;
A first microwave generator connected to the first antenna;
A second microwave generator connected to the second antenna;
A control unit for controlling the first microwave generation unit and the second microwave generation unit;
Have
The first recess reflects the microwave radiated from the first antenna;
The microwave heating apparatus, wherein the second recess reflects the microwave radiated from the second antenna. A heating chamber in which an object to be heated is placed;
A first antenna and a second antenna provided in the heating chamber;
A first microwave generator connected to the first antenna;
A second microwave generator connected to the second antenna;
A control unit for controlling the first microwave generation unit and the second microwave generation unit;
A partition formed by a material that reflects microwaves provided between the first antenna and the second antenna;
A microwave heating apparatus comprising: The heated object is placed at a position immediately above the first antenna and the second antenna,
When heating the first region of the object to be heated, the control unit generates microwaves from the first microwave generation unit, radiates microwaves from the first antenna, and Heating the first region of the object to be heated;
When heating the second region of the object to be heated, microwaves are generated from the second microwave generator, microwaves are emitted from the second antenna, and the second region of the object to be heated is emitted. The microwave heating apparatus according to claim 1, wherein the two regions are heated.   4. The microwave heating according to claim 1, wherein the first microwave generation unit and the second microwave generation unit include a semiconductor element formed of a nitride semiconductor. 5. apparatus. A direct current power source is connected to the first microwave generation unit and the second microwave generation unit, and the semiconductor element in the first microwave generation unit and the second microwave generation unit The microwave heating apparatus according to claim 4, wherein microwaves are generated by switching between the two.

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