JP2002164161A - Microwave heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize uniform heating and selective heating of the heated object in the heating case in a microwave heating device. SOLUTION: In a microwave heating device, microwave is supplied through the airtight coaxial waveguide 18 having a rotation function in the heating case 1, and a microwave radiation antenna 17 that is jointed to the inner conductor 181 of this coaxial waveguide 18 is rotated by a rotation drive part 19, thus uniform heating and selective heating are made possible in this structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron application device which is a high-frequency device, and more particularly to a microwave heating device using a magnetron as an oscillation tube.

[0002]

2. Description of the Related Art Generally, a microwave oven is known as a microwave heating apparatus using a magnetron as an oscillation tube.

[0003] A microwave oven heats an object by using a microwave (high frequency) generated by a magnetron and thus has a high heating efficiency and is widely used not only for home use but also for industrial use.

FIG. 7 is a schematic diagram for explaining an example of the structure of a microwave oven in a conventional microwave heating apparatus. In FIG. 7, reference numeral 1 denotes a microwave oven heating housing (oven); Heater, 4 stirrer, 5 magnetron, 5a magnetron antenna, 6 waveguide, 8 magnetron 5
Reference numeral 302 denotes a door, 307 denotes a fan, and 308 denotes cooling air generated by the fan 307.

In this apparatus, first, the object 3 to be heated is set from the door 302 into the housing 1 for heating. The microwave generated by the magnetron 5 is radiated from the magnetron antenna 5a of the magnetron 5, is supplied through the waveguide 6 into the heating housing 1 having the object 3 to be heated, and heats the object 3 to be heated.

At this time, since the magnetron 5 generates heat, the magnetron 5 is cooled by the cooling air 308 sent by the fan 307.

On the other hand, the microwave power supplied into the heating housing 1 is stared so that the object to be heated 3 is uniformly heated.
Is diffused by the laser 4.

FIG. 8 is a schematic view for explaining an example of the structure of a microwave oven of a type in which the inside of a heating housing is pressurized to cooperate with microwaves in a conventional microwave heating apparatus. Alternatively, they indicate the same function.

In FIG. 8, reference numeral 1 denotes a heating housing, which has a structure composed of a combination of a plurality of housings of an upper housing 1a and a lower housing 1b. Body 1
a and the lower housing 1b. Reference numeral 2 denotes a tray rotatably supported by a support rod 2a. 2b is tray 2
Of the driving device. Reference numeral 7 denotes a gas discharge unit that has a function of discharging gas used to increase the pressure in the housing 1 for heating. A high voltage cable 8a connects the magnetron 5 and the power supply unit 8. Reference numeral 9 denotes a dielectric, which functions to maintain the confidentiality of the heating casing 1 and to protect the magnetron 5 and the waveguide 6 and the like from steam, heat, etc. generated in the heating casing 1. have. Reference numeral 10 denotes a pressurizing system, which has a function of sending gas such as air from the pressurized gas supply pipe 10a through the hole 10b into the housing 1 for heating, thereby increasing the pressure inside the housing 1 for heating. ing. 13 is a temperature sensor, 14 is a pressure sensor, 15 is a position sensor, 1
6 is a choke.

In the configuration shown in FIG. 8, the microwave generated by the magnetron 5 is radiated from the magnetron antenna 5a and supplied through the waveguide 6 into the heating housing 1 having the object 3 to be heated. At this time, since the magnetron 5 generates heat,
Cooled by cooling air.

On the other hand, the microwave power supplied into the heating housing 1 is stared so that the object 3 to be heated is uniformly heated.
Is diffused by the laser 4.

The stirrer 4 is made of a metal material for reflecting radio waves, and is rotatably supported by a rod 4a. Reference numeral 4b denotes a driving device.

As described above, the heating housing 1 includes the upper housing 1a and the lower housing 1b, each of which has a metal inside, and when these are vertically aligned, a predetermined amount or more of microwaves is transmitted from the joint 1c. A configuration that does not cause leakage, for example, a choke 16 is provided in this example.

Further, the heating housing 1 is configured to be airtight so that the inside of the housing 1 can be used at a high pressure.

As a technique related to the microwave heating apparatus having the structure as shown in FIG.
No. 8710, Japanese Utility Model Publication No. Sho 60-21975, and the like, which disclose a heating sterilizer for irradiating a microwave to a heating housing controlled to a high pressure, are disclosed.

[0016]

In the microwave heating apparatus of the prior art described above, particularly, a microwave heating apparatus in which pressurization and microwave heating are combined, the evaporation of water from the object to be heated exceeds 100 ° C. It is characterized in that it can be heated to a temperature of 100 ° C. or higher without a large loss of energy due to heat of evaporation.

However, in such a microwave heating apparatus, it is necessary to arrange a radio wave diffusion stirrer, a rotating mechanism for the object to be heated, and the like inside the housing for heating in which the object to be heated is accommodated. There are problems to be solved in terms of securing space in the heating housing and uniform heating.

Further, since the power supply waveguides and the like are arranged in a plane around the heating casing, there are many restrictions on the configuration of the apparatus, and a plurality of heating casings are used as a mass production apparatus. There is a problem to be solved in terms of space and maintenance, such as the case of operating in parallel.

An object of the present invention is to solve the above-mentioned problems of the prior art, to provide a compact structure, to easily obtain uniform heating and selective heating in a heating housing, and to be useful as a mass production apparatus. It is to provide a device.

[0020]

In order to achieve the above-mentioned object, the present invention provides a microwave heating apparatus combining pressurization and microwave heating, in which a heating housing for accommodating an object to be heated is hermetically sealed. A coaxial waveguide is placed through the antenna, and the coaxial waveguide and the antenna are coupled in the heating housing. By rotating the antenna and the coaxial waveguide, uniform heating and selective heating can be performed. It was done.

A typical configuration of the present invention is described as follows. That is, (1) a heating housing part having a space for accommodating an object to be heated, a microwave power supply part for supplying microwave power to the inside of the heating housing part, A waveguide coupled to the power supply unit, a coaxial waveguide coupled at one end to the waveguide and coupled at the other end to an antenna disposed in the heating housing, It has a rotation drive unit for rotating a tube and the antenna, and a pressurizing system unit for increasing the pressure inside the heating housing. (2) In the above (1), the heating casing is constituted by an aggregate of a plurality of casing components. (3) In the above (1) or (2), the heating housing includes an upper housing in which the antenna is arranged and a lower housing for housing an object to be heated. (4) In the above (1), the antenna is coupled to an inner conductor of the coaxial waveguide. (5) A heating housing having a space for accommodating an object to be heated, a microwave power supply unit for supplying microwave power to the inside of the heating housing, and a microwave power supply A coaxial waveguide having one end coupled to the waveguide and the other end coupled to an antenna disposed in the housing for heating; and a coaxial waveguide coupled to the antenna. A microwave drive unit for rotating the antenna and a pressurizing system unit for increasing the pressure inside the heating housing, and inserting the object to be heated into the heating housing unit to generate microwaves; In performing the heating, the microwave power supply unit is operated intermittently. (6) In the above (5), the pressurizing system section is intermittently operated in conjunction with the intermittent operation of the microwave power supply section.

It should be noted that the present invention is not limited to the above configuration and the configuration of the embodiment described later, and various modifications can be made without departing from the technical idea of the present invention.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to examples.

FIG. 1 is a schematic view showing an embodiment of the microwave heating apparatus according to the present invention, wherein the same reference numerals as those in the above-mentioned figures indicate the same parts or the same functions.

In FIG. 1, reference numeral 17 denotes an antenna. The antenna 17 is formed in a strip shape. One end of the inner conductor at one end 18a of the coaxial waveguide 18 and the inner conductor and the outer conductor And one end surface of an insulator interposed therebetween is suspended in the housing 1 for heating,
It is held rotatable 360 °.

The other end 18b of the coaxial waveguide 18 penetrates through the rotation drive unit 19 and enters the waveguide 6, and extends to a position where its end surface contacts the zenith surface of the waveguide 6. .

The rotation drive unit 19 has an actuator (ACTUATOR). One end of the rotation drive unit 19 is fixed to the waveguide 6, and the penetrating coaxial waveguide 18 can be rotated at the center thereof. Holding. In addition, this rotation drive unit 1
Reference numeral 9 denotes a side opposite to the side fixed to the waveguide 6 and is connected to the housing 1 for heating. 20 is a circuit monitor.

Here, since the antenna 17 is rotatably held as described above, even if the tray 2 is not provided with a special rotating mechanism, uniform heating is possible.

Next, FIG. 2 is an enlarged sectional view of a main part around the rotation drive unit 19 in FIG.

In FIG. 2, the coaxial waveguide 18 includes an inner conductor 181 made of, for example, a copper wire having a diameter of about 5 mm,
A cylindrical outer conductor 182 having an inner diameter of about 18 mm made of stainless steel or the like, and an insulator 183 made of ceramic or the like interposed between them to insulate both members are joined to each other.

The outer conductor 182 is provided with a flange portion (flange) 184 protruding in the outer peripheral direction on a part thereof.
84 is fixed to a rotation shaft 192 of an actuator 191 of the rotation drive unit 19 via a disk 193.

The rotating shaft portion 192 is rotatably connected to the main body via two bearings 194 and 195. In this example, the actuator 191 is a shock absorber type (SHOCK ABSORBER).
TYPE).

The end 181a of the inner conductor 181 on the side of the waveguide 6 extends from the bottom 6a of the waveguide 6 to the inside of the waveguide 6, and propagates through the waveguide 6. It is easy to send and receive microwaves.

On the other hand, the outer conductor 182 has the upper end 1
82a is in contact with the bottom 6a of the waveguide 6, and this bottom 6a is connected to the rotary drive 19 via the intermediate plate 20.

On the other hand, the rotation driving section 19 is on the opposite side to the waveguide 6, and has an outer peripheral portion 196 of a support 196, an example of which is shown in FIG.
a, and a central portion 196b of the support 196 is connected to one end 21a of a holding structure 21, which will be described later, connected to the heating housing 1 by two nuts 22.

Here, FIGS. 3A and 3B show details of an example of the support, FIG. 3A is a plan view, and FIG. 3B is a front view in which a main part of FIG. is there.

The holding structure 21 is provided with the coaxial waveguide 1.
8, and a predetermined gap is maintained between the two members.

Next, FIG. 4 is an enlarged sectional view of a main part around the antenna 17 of FIG.

In FIG. 4, the other end 21 of the holding structure 21
b connects the flange 211 on the end face to the upper housing 1a of the housing 1 for heating.

Accordingly, the housing 1 for heating is mechanically connected to the waveguide 6 via the holding structure 21, the support 196, the rotation drive unit 19 and the intermediate plate 20.

The coaxial waveguide 18 has a part extending from the one end 18a side to the inner space of the heating housing 1, and has one end face of the inner conductor 181 and the inner conductor 181 and the outer conductor 18a.
2 and one end face of an insulator 183 interposed between the antenna 2 and the antenna 17. The outer conductor 182 is arranged at a position not in contact with the antenna 17.

Further, two O-rings 23 (231, 232) are interposed in a gap between one end 18a of the coaxial waveguide 18 and the other end 21b of the holding structure 21, and these O rings 23 (231, 232) are inserted. It has a plurality of functions of maintaining a gap and an airtight seal mechanism for preventing leakage of pressure of the heating housing 1.

As described above, the microwave heating apparatus shown in FIGS. 1 to 4 is an apparatus capable of performing processing in cooperation with pressurization and microwave heating, and also includes an antenna for microwave irradiation which is a housing for heating. This antenna is arranged inside the body, the antenna and the inner conductor of the coaxial waveguide that penetrates the heating casing airtightly are coupled, and the antenna and the coaxial waveguide are configured to be rotatable. Uniform heating and selective heating become easier as well as securing space in the body.

Further, in the configuration in which the antenna is held on the upper housing side, since the object to be heated is placed on the lower housing side,
The present invention is also suitable for a mass production apparatus in which a lower housing on which an object to be heated is placed is sequentially transferred by, for example, a conveyor system.

Next, FIG. 5 is a view showing a sectional structure of an example of a magnetron used in the microwave heating apparatus according to the present invention, and the same reference numerals as those in the above-mentioned drawings indicate the same parts or the same functions.

In FIG. 5, a plurality of anode vanes 102 are fixed to the anode cylinder 103 by brazing or the like around the spiral cathode filament 101, or are integrally formed with the anode cylinder 103 by extrusion molding. .

Above and below the anode cylinder 103, cylindrical permanent magnets 104 are disposed via magnetic poles 105 made of a ferromagnetic material such as soft iron. In the figure, 106 is a yoke, 107 is an antenna lead, and one end is cut off with the anode vane 102 and the other end is sealed off together with the exhaust pipe 108. 109 is a choke portion, 110 is an antenna cover, 111 is a cylindrical insulator, 112 is an exhaust pipe support, and the antenna lead 107, the exhaust pipe support 112 and the like constitute the magnetron antenna 5a. .

Also, 121 and 122 are upper end shield and lower end shield, 123 and 124 are cathode leads (123 is a center lead, 124 is a side lead),
125 is an input side ceramic, 126 is a cathode terminal, 127
Is a spacer, and the spacer 127 has a function of preventing disconnection of the cathode filament 101.
It is arranged at a predetermined position at 28.

The choke coil 131 is a feedthrough capacitor 1
The feedthrough capacitor 132 is connected to one end of the input 32 and is attached to a case 133 of the input section. The other end of the feedthrough capacitor 132 is connected to the power supply 8. Further, the bottom of the case 133 is closed by a cover 134 in a high frequency manner. 141 and 142 are cap-shaped upper and lower sealing metals;
Is a metal gasket, which is connected to the upper yoke 144.

The structure, function and operation of each part of the magnetron shown in FIG. 5 are general without any particular difference from the conventional one, and further detailed description will be omitted.

FIG. 6 is a waveform diagram for explaining an example of a driving method of the microwave heating apparatus, and the horizontal axis represents time (second).
The vertical axis represents the temperature of the object to be heated and the pressure (a
tm).

The operating condition is 3K under a pressure of 3 atm.
The microwave of W was irradiated from the rotating antenna. Irradiation is 1
An intermittent heating method in which ON-OFF is repeated in 0 to 20 seconds was used, and pressurization was also performed at the same time.

In FIG. 6, a line A indicates a change in pressurization in the heating housing, and indicates that pressurization and depressurization were repeated in synchronization with microwave irradiation. The line B and the line C show the temperature change of the object to be heated.

The line B represents the temperature of the object placed near the center of the rotary antenna among the objects set on the tray in the heating housing, and the line C
Are measured and displayed temperatures of objects to be heated arranged at positions away from the center of the rotary antenna.

Line D is a magnetron ON-OF.
The timing of F is shown. The operation timing of the magnetron is synchronized with the start of pressurization and the end of depressurization, and the ON-OFF is repeated every 15 seconds.

As is evident from FIG. 6, it is clear that the temperature of the object to be heated differs depending on the position where it is arranged in the initial stage of heating.
It is possible to keep the temperature substantially constant irrespective of the arrangement position by repeating -OFF.

This is an excellent thing that can process a large amount of the object to be heated in a short time.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical concept of the present invention. For example, a plurality of the microwave heating apparatuses shown in FIG. 1 can be arranged in series along a line. When the magnetron is OFF, that is, when the magnetron is not pressurized, the object to be heated can be moved to the next device, so that heating can be performed sequentially.

For example, see Japanese Patent Application Laid-Open No. 2000-228281.
The present invention may be applied to a magnetron heating device described in Japanese Patent Application Laid-Open Publication No. H10-26095.

[0060]

As described above, according to the present invention,
A configuration in which a microwave is fed through a coaxial waveguide having a rotating function in a hermetically sealable heating case in a hermetic manner, and a microwave radiation antenna coupled to an inner conductor of the coaxial waveguide is rotated. Because it has a compact structure,
This is an apparatus that can perform processing in cooperation with pressurization and microwave heating, and secures space in the heating housing, and further facilitates uniform heating and selective heating.

Further, in the configuration in which the antenna is held on the upper housing side, since the object to be heated is placed on the lower housing side,
It is possible to provide a useful microwave heating apparatus which is suitable for a mass production apparatus in which a lower housing on which an object to be heated is sequentially transferred by, for example, a conveyor system.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a microwave heating apparatus according to the present invention.

FIG. 2 is an enlarged sectional view of a main part around a rotation drive unit in FIG.

3A and 3B are views for explaining the structure of an example of the support shown in FIG. 2, wherein FIG. 3A is a plan view and FIG. 3B is a partial cross-sectional front view of FIG.

FIG. 4 is an enlarged sectional view of a main part around the antenna of FIG. 1;

FIG. 5 is a sectional view of an example of a magnetron used in the microwave heating device of the present invention.

FIG. 6 is a waveform diagram for explaining a driving method of the microwave heating device according to the present invention.

FIG. 7 is a schematic diagram illustrating a structure of an example of a conventional microwave heating device.

FIG. 8 is a schematic diagram illustrating the structure of another example of a conventional microwave heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating housing 1a Upper housing 1b Lower housing 2 Tray 3 Heated object 5 Magnetron 5a Magnetron antenna 6 Waveguide 7 Gas discharge part 8 Magnetron power supply 10 Pressurization system part 17 Antenna 18 Coaxial waveguide 181 Inner conductor 182 Outer conductor 183 Insulator 184 Flange 19 Rotation drive unit 21 Holding structure 23 O-ring.

Continued on the front page (72) Inventor Tohru Moriike 3350 Hayano, Mobara-shi, Chiba F-term (reference) in Hitachi Electronics Devices, Ltd. BB13 CA01 DA04 EA01 EA03 EB03 EB29

Claims (6)

[Claims] A heating housing having a space for accommodating an object to be heated, a microwave power supply for supplying microwave power to the interior of the heating housing, and a microwave power supply; A waveguide coupled to the power supply unit, a coaxial waveguide coupled at one end to the waveguide and coupled at the other end to an antenna disposed in the heating housing, A microwave heating device, comprising: a rotation drive unit for rotating a tube and the antenna; and a pressurizing system unit for increasing the pressure inside the housing for heating. 2. The microwave heating apparatus according to claim 1, wherein said heating housing is composed of an aggregate of a plurality of housing components. 3. The microwave heating apparatus according to claim 1, wherein said heating housing has an upper housing in which said antenna is arranged and a lower housing for housing an object to be heated. . 4. The microwave heating apparatus according to claim 1, wherein said antenna is coupled to an inner conductor of said coaxial waveguide. 5. A heating housing portion having a space for accommodating an object to be heated, a microwave power supply portion for supplying microwave power to the inside of the heating housing portion, and a microwave power supply portion. A waveguide coupled to the power supply unit, a coaxial waveguide coupled at one end to the waveguide and coupled at the other end to an antenna disposed in the heating housing, A rotation drive unit for rotating the tube and the antenna, and a pressurizing system unit for increasing the pressure inside the heating housing, and inserting the object to be heated into the heating housing unit. A microwave heating apparatus, wherein the microwave power supply unit is operated intermittently when performing microwave heating. 6. The microwave heating apparatus according to claim 5, wherein the pressurizing system section is intermittently operated in conjunction with the intermittent operation of the microwave power supply section.