JP6807522B2 - High frequency heating device - Google Patents

Description

The present invention relates to a high frequency heating device provided with a surface wave exciter using a periodic structure.

Conventionally, there has been disclosed a technique relating to a high frequency heating device that supplies high frequency electric power to a surface wave exciter using a periodic structure to heat an object to be heated such as food.

For example, in Patent Document 1, high-frequency heating capable of supplying microwaves to a surface wave transmission line to brown the surface of food by utilizing the characteristic of surface waves in which the side close to the surface wave exciter is strongly heated. The device is disclosed.

Further, Patent Document 2 discloses a cooking cooker capable of heating and browning the upper surface of food by providing a radiant heating source at a position facing the surface wave exciter.

Jikkai Sho 56-98 Japanese Unexamined Patent Publication No. 8-210653

However, among the above-mentioned conventional configurations, especially in Patent Document 1, since the characteristic of the surface wave in which the side close to the surface wave exciter is strongly heated is utilized, the portion close to the surface wave exciter is strongly heated and relatively. A thin food is sufficiently heated, but a thick food is likely to be insufficiently heated because the heating becomes weaker as the distance from the surface wave exciter increases. Further, regardless of the thickness of the food, it is difficult to brown the surface of the food opposite to the surface wave exciter.

Further, in Patent Document 2, the entire food can be heated by providing a radiant heating source at a position facing the surface wave exciter and supplementing the portion where the heating is weak by the surface wave heating with radiant heating. It is possible to brown the half-faced surface wave exciter of food, but since it is necessary to equip two types of heating sources, the structure becomes complicated and a large amount of power is required.

The present invention solves the above-mentioned conventional problems. In a high-frequency heating device provided with a surface wave exciter, the present invention has a simple structure and both sides of the object to be heated without using another heat source such as a heater. It is an object of the present invention to provide a high frequency heating device capable of heat treatment.

In order to solve the above-mentioned conventional problems, the high-frequency heating device of the present invention includes a high-frequency power generating unit that generates high-frequency power and a plurality of surface wave exciters that propagate the high-frequency power by surface waves to heat an object to be heated. A high-frequency power supply unit that supplies the high-frequency power to the surface wave exciter, and an installation table on which the object to be heated is installed, and the plurality of surface wave exciters sandwich the object to be heated. The high-frequency power is supplied from the high-frequency power generating unit only to one of the surface wave exciters, and the other surface wave exciter is supplied from the one surface wave exciter.
High-frequency power propagates to heat the object to be heated .

With this configuration, high-frequency power is supplied to a plurality of surface wave exciters installed at opposite positions so as to sandwich the object to be heated, and the object to be heated is heat-treated by the high-frequency power propagating the surface wave exciter by the surface wave. Therefore, with a simple structure, both sides of the object to be heated can be heat-treated without using another heat source having high power consumption such as a heater.

The high-frequency heating device of the present invention has a simple structure because it heat-treats a plurality of surface wave exciters installed at opposite positions so as to sandwich the object to be heated with high-frequency power propagating by surface waves. Both sides of the object to be heated can be heat-treated without using another heat source having high power consumption such as a heater.

Block diagram showing the basic configuration of the high frequency heating device of the first embodiment Block diagram showing the configuration of the high-frequency power supply unit The figure which shows the operation of the high frequency heating apparatus of Embodiment 1. Block diagram showing the basic configuration of the high frequency heating device of the second embodiment The figure which shows the operation of the high frequency heating apparatus of Embodiment 2. Block diagram showing the basic configuration of the high frequency heating device of the third embodiment The figure which shows the operation of the high frequency heating apparatus of Embodiment 3. The figure which shows the state of the change of the surface concentration degree of an electric field when the frequency of high frequency power is changed.

The first invention comprises a high-frequency power generating unit that generates high-frequency power, a plurality of surface wave exciters that propagate the high-frequency power by surface waves to heat an object to be heated, and the surface wave exciter that transmits the high-frequency power. A high-frequency power supply unit for supplying power to the object to be heated and an installation table for installing the object to be heated are provided, and the plurality of surface wave exciters are installed at opposite positions so as to sandwich the object to be heated , and one of them is provided. The high-frequency power is supplied from the high-frequency power generating unit only to the surface wave exciter of the above, and the high-frequency power propagates from the one surface wave exciter to the other surface wave exciter to heat the object to be heated. With such a structure, both sides of the object to be heated can be heat-treated without using another heat source having a large power consumption such as a heater.

The second invention, particularly in the first invention, is such that the height is applied to each of the plurality of surface wave exciters.
Since the high-frequency power is supplied from the frequency power generator, the heating state of each surface wave exciter can be controlled in more detail, and the finished quality by heating the object to be heated can be further improved. Can be done.

A third invention, particularly in any one of the first and second inventions, is the high frequency power generating unit.
Is a frequency-variable high-frequency oscillator that generates high-frequency power of a set frequency, so the frequency of high-frequency power supplied to the surface wave exciter can be changed, so the surface wave exciter is propagated by surface waves. By changing the propagation state of the high-frequency power to be heated, the heating state for the object to be heated can be changed according to preference.

A fourth invention, particularly in any one of the first to third inventions, is a surface wave exciter because the high frequency power generating unit is a frequency variable high frequency oscillator that generates high frequency power of a set frequency. Since the frequency of the high-frequency power supplied to the device can be changed, the heating state of the object to be heated can be changed according to preference by changing the propagation state of the high-frequency power propagating the surface wave exciter by the surface wave. Can be made to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment.

(Embodiment 1)
FIG. 1 is a block diagram showing a basic configuration of a high-frequency heating device 100 according to a first embodiment of the present invention.

The high-frequency heating device 100 shown in the figure is a high-frequency heating device that heat-treats the object to be heated 102 installed on the installation table 101, and includes the first surface wave exciter 103a and the second surface wave exciter 103b. , A first high frequency power supply unit 110a, a second high frequency power supply unit 110b, and a high frequency power generation unit 120 are provided. Further, the first surface wave exciter 103a and the second surface wave exciter 103b are installed at positions facing each other so as to sandwich the object to be heated 102.

In FIG. 1, the high-frequency heating device 100 has two surface wave exciters, two high-frequency power supply units, and one high-frequency power generator. However, the surface wave exciter and the high-frequency power supply unit And the number of high frequency power generators is not limited to this. For example, four surface wave exciters may be configured to sandwich the object to be heated from four directions, and at least one high-frequency power generating unit and one high-frequency power supply unit may be included in one surface wave exciter. There may be two each, or more.

In FIG. 1, the high-frequency power generated by the high-frequency power generation unit 120 is transferred to the first surface wave exciter 103a via the first high-frequency power supply unit 110a and via the second high-frequency power supply unit 110b. It is supplied to each of the surface wave exciter 103b of 2. Then, the high-frequency power supplied to the first surface wave exciter 103a and the second surface wave exciter 103b propagates each surface wave exciter by the surface wave to heat the object to be heated 102. In the following description, the first surface wave exciter 103a and the second surface wave exciter 103b, the first high frequency power supply unit 110a, and the second high frequency power supply unit 110b are not particularly distinguished, and the surface surface is not particularly distinguished. It may be described as a wave exciter 103 and a high frequency power supply unit 110.

The high-frequency power generator 120 is a high-frequency transmitter that outputs high-frequency power having a frequency (for example, microwave) and power suitable for heat-treating the object to be heated 102. For example, it may be composed of a magnetron and an inverter power supply circuit, or may be composed of a solid-state oscillator and a power amplifier.

A magnetron is a type of oscillating vacuum tube that generates strong non-coherent microwaves, which is a type of radio wave, and is often used in high-power applications of hundreds to several kilowatts such as radars and microwave ovens. Since a high voltage of several kilovolts is required to drive the magnetron, an inverter power supply is generally used as the drive power source for the magnetron. The inverter power supply is a power supply circuit composed of a converter circuit having a rectifying function and an inverter circuit having a step-up (or step-down) function and an output frequency conversion function, and is a technology widely used for lighting devices and motor control.

On the other hand, a solid-state oscillator is a semiconductor oscillator circuit in which a feedback circuit is composed of transistors and high-frequency electronic components such as capacitors, inductors, and resistors, and is a technology widely used in oscillators for low-power output applications such as communication equipment. .. In recent years, the high-frequency power output from a solid-state oscillator has a high output of about 50 watts, but generally it is about several tens of milliwatts to several hundreds of milliwatts, and several hundreds of watts for use in heat treatment applications. Since the output power of is required, generally, the high frequency power output from the solid-state oscillator is amplified by a power amplifier such as a transistor.

The high-frequency power supply unit 110 corresponds to a power connection unit that supplies high-frequency power generated by the high-frequency power generation unit 120 to the surface wave exciter 103. The configuration of the high frequency power supply unit 110 will be described later.

The surface wave exciter 103 is formed of a metal periodic structure in which impedance elements are periodically arranged on a metal plate, or a dielectric plate. For example, in a metal periodic structure, a stub-type surface wave exciter in which a plurality of metal plates are arranged on a metal plate at regular intervals in a direction of standing toward an object to be heated, or an interdigital in which metal plates are punched out in a crossed finger shape. A mold surface wave exciter can be used, and as the dielectric plate, an alumina plate or a bakelite plate can be used.

The surface wave exciter 103 can propagate the high frequency power supplied from the high frequency power generation unit 120 via the high frequency power supply unit 110 by concentrating the high frequency power in the vicinity of the surface of the surface wave. As a result, the installation table 101 is provided in the vicinity of the surface wave exciter 103, and the object to be heated 102 is installed on the installation table 101, so that the high frequency power concentrated in the vicinity of the surface by the surface wave exciter 103 causes the installation table 101. The object to be heated 102 is heated.

Here, the configurations of the first high-frequency power supply unit 110a and the second high-frequency power supply unit 110b in the present embodiment will be described with reference to the drawings.

FIG. 2 is a block diagram showing an example of the configuration of the first high-frequency power supply unit 110a.

The figure shows a configuration in which the high-frequency power generated by the high-frequency power generation unit 120 is guided to the first high-frequency power supply unit 110a by using the rectangular waveguide 130.

The square waveguide 130 is the most common waveguide, a metal tube having a rectangular (generally rectangular) cross-sectional shape, and is a hollow waveguide mainly used for microwave transmission. is there. Electromagnetic waves propagate in a tube while forming an electromagnetic field according to its shape, size, wavelength or frequency.

In order to supply the high-frequency power propagated from the high-frequency power generating unit 120 to the first surface wave exciter 103a by the rectangular waveguide 130, the square waveguide 130 and the first surface wave exciter 103a are tapered. By connecting with the rectangular waveguide 131 of the shape, the reflection at the joint portion is reduced, and the loss can be reduced. As shown by the broken line in FIG. 2, the first high-frequency power supply unit 110a includes a part of the rectangular waveguide 130, a tapered rectangular waveguide 131, and a part of the surface wave exciter 103. Has been done.

As a result, the high-frequency power generated by the high-frequency power generation unit 120 and guided to the first high-frequency power supply unit 110a via the square waveguide 130 is transmitted to the first high-frequency power supply unit 110a via the tapered square waveguide 131. Is efficiently supplied to the surface wave exciter 103a. Since the second high-frequency power supply unit 110b has the same configuration as the first high-frequency power supply unit 110a, the description thereof will be omitted.

With the above configuration, the high frequency heating device 100 according to the present embodiment transfers the high frequency power generated by the high frequency power generation unit 120 to the first high frequency power supply unit 110a and the second high frequency power supply unit 110b. By supplying the first surface wave exciter 103a and the second surface wave exciter 103b via the surface wave, the first surface wave exciter 103a and the second surface wave exciter 103b are propagated by the surface wave, respectively. The high-frequency power generated allows heat treatment to be performed on both sides of the object to be heated 102 installed on the installation table 101 without using another heat source such as a heater, and further, both sides of the object to be heated 102 are browned. Can also be attached.

In particular, when the heater of the conventional example is used, the power consumption is about 800 W to 1000 W when trying to brown the object to be heated, but when the high frequency power generating part in the present invention is used, the power consumption is high. Since it only takes about 100W to 200W, it is also excellent in energy saving performance. Further, in the heater, the surface and the inside of the object to be heated have a hard texture, but when a surface wave exciter is used in the overall configuration of the present invention, the surface of the object to be heated has a hard surface but the inside has a soft finish. , It is possible to produce a texture different from that when a heater is used.

Next, the operation of heat-treating the object to be heated 102 of the high-frequency heating device 100 described above will be described.

FIG. 3 shows a surface wave exciter 103 when the high frequency power generated by the high frequency power generation unit 120 is supplied to the surface wave exciter 103 shown in FIG. 1 via the high frequency power supply unit 110. The state of the electric field strength distribution in the vicinity of the surface of each surface wave exciter 103 of the high-frequency power propagated in the above is schematically shown.

FIG. 3A shows a first surface when the high frequency power generated by the high frequency power generation unit 120 is supplied to the first surface wave exciter 103a via the first high frequency power supply unit 110a. The electric field strength distribution 140a near the surface of the wave exciter 103a is shown in FIG. 3 (b), and the high frequency power generated by the high frequency power generating unit 120 is applied to the first surface wave exciter 103a. When the object to be heated 102 is installed on the installation table 101 by supplying it through the power supply unit 110a, the object to be heated 102 is heated by the electric field strength distribution 140b near the surface of the first surface wave exciter 103a. In FIG. 3C, the second surface wave exciter 103b is arranged so as to sandwich the object to be heated 102 with respect to the first surface wave exciter 103a, and is generated by the high frequency power generating unit 120. The generated high-frequency power is supplied to the first surface wave exciter 103a via the first high-frequency power supply unit 110a, and to the second surface wave exciter 103b via the second high-frequency power supply unit 110b. When the object to be heated 102 is supplied and installed on the installation table 101, the object to be heated 102 is based on the electric field strength distribution 140c near the surfaces of the first surface wave exciter 103a and the second surface wave exciter 103b. Are shown to be heated.

Here, the electric field strength distributions 140a, 140b, and 140c represent the strength of the electric field by the shade of color, and the darker the color, the stronger the electric field.

As shown in FIG. 3A, when the high frequency power generated by the high frequency power generation unit 120 is supplied to the first surface wave exciter 103a via the first high frequency power supply unit 110a, the first surface wave is generated. The high-frequency power supplied to the exciter 103a propagates on the first surface wave exciter 103a by the surface wave, so that the electric field strength distribution 140a near the surface of the first surface wave exciter 103a is the first. The electric field near the surface of the surface wave exciter 103a becomes stronger, and the electric field becomes exponentially weaker as the distance from the surface of the first surface wave exciter 103a increases.

Further, as shown in FIG. 3B, in a state where the object to be heated 102 is installed on the installation table 101, the high-frequency power generated by the high-frequency power generation unit 120 is applied to the first surface wave exciter 103a. When supplied via the high-frequency power supply unit 110a of No. 1, the electric field strength distribution 140b near the surface of the first surface wave exciter 103a becomes the first surface wave exciter 103a as in FIG. 3A described above. Since the electric field near the surface of the first surface wave exciter 103a becomes stronger and the electric field becomes weaker as the distance from the surface of the first surface wave exciter 103a increases, the portion of the object 102 to be heated near the first surface wave exciter 103a (heated). The lower surface portion of the object 102) is intensively and strongly heated, and the portion far from the first surface wave exciter 103a (the upper surface portion of the object 102 to be heated) is heated very weakly or hardly heated.

Further, as shown in FIG. 3C, in a state where the object to be heated 102 is installed on the installation table 101, the second surface wave so as to sandwich the object to be heated 102 with respect to the first surface wave exciter 103a. The exciter 103b is arranged, and the high-frequency power generated by the high-frequency power generation unit 120 is transferred to the first surface wave exciter 103a via the first high-frequency power supply unit 110a, and the second high-frequency power supply unit 110b is provided. When each is supplied to the second surface wave exciter 103b via the above, the electric field strength distribution 140c in the space sandwiched between the first surface wave exciter 103a and the second surface wave exciter 103b becomes the first surface wave. Since the electric field near the surface of the exciter 103a and the second surface wave exciter 103b becomes stronger and the electric field becomes weaker as the distance from the surface increases, the first surface wave exciter 103a of the object 102 to be heated has a distribution. And the portion close to the second surface wave exciter 103b (the upper surface and the lower surface portion of the object 102 to be heated) is intensively and strongly heated and sandwiched between the first surface wave exciter 103a and the second surface wave exciter 103b. The intermediate portion of the space (the intermediate layer portion of the object to be heated 102) is in a weakly heated state. As a result, both sides of the object to be heated 102 installed on the installation table 101 can be heat-treated, and further, the upper surface and the lower surface of the object to be heated 102 can be mainly browned.

Further, by using the surface wave exciters having the same excitation frequency for the plurality of surface wave exciters 103, the design of the device is facilitated, and the heating state of each surface wave exciter is balanced and finished. The quality can be improved.

The excitation frequency of a surface wave exciter is determined by the material used and the physical structural dimensions. For example, in the above-mentioned stub type surface wave exciter, the excitation frequency of the surface wave exciter can be changed by changing the height dimension of a plurality of metal flat plates arranged on the metal flat plate, the spacing dimension of the metal flat plates, and the like. It can be varied to form a surface wave exciter with the desired excitation frequency. In principle, the excitation frequency of the surface wave exciter becomes higher as the height dimension of the metal flat plate is lowered, and becomes higher as the spacing dimension of the metal flat plate is reduced. Therefore, the metal flat plate is adjusted in this way. By doing so, a surface wave exciter having a desired excitation frequency can be formed.

In the present invention, the excitation frequency of the surface wave exciter may be adjusted as described above, and a surface wave exciter having the same excitation frequency may be used for the plurality of surface wave exciters 103.

In the high-frequency heating device 100 of FIG. 1, the first high-frequency power supply unit 110a and the second high-frequency power supply unit 110b are provided with respect to the first surface wave exciter 103a and the second surface wave exciter 103b. Although it is described that the high frequency power from the high frequency power generating unit 120 is supplied from the same direction by being provided in the same direction, the high frequency power to the first surface wave exciter 103a and the second surface wave exciter 103b is applied. The supply direction may be the opposite direction or other directions.

(Embodiment 2)
Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings.

In the description of the second embodiment, the same reference numerals are given to the components having the same functions as those of the first embodiment, and the description thereof will be omitted. Further, the description of the content having the same effect as that of the first embodiment described above will be omitted.

FIG. 4 is a block diagram showing the configuration of the high frequency heating device 200 according to the second embodiment of the present invention.

The high-frequency heating device 200 shown in the figure is a second surface wave exciter 103a instead of the first surface wave exciter 103a and the second surface wave exciter 103b, as compared with the high-frequency heating device 100 according to the first embodiment shown in FIG. A surface wave exciter 203a and a second surface wave exciter 203b are provided, and a high frequency power supply unit 210 is provided in place of the first high frequency power supply unit 110a and the second high frequency power supply unit 110b, and a high frequency power generation unit is provided. A high frequency power generation unit 220 is provided instead of the 120.

In FIG. 4, the high-frequency heating device 200 has two surface wave exciters, one high-frequency power supply unit, and one high-frequency power generation unit, but the surface is the same as in the first embodiment. The number of wave exciters, high-frequency power supply units, and high-frequency power generation units is not limited to this.

The high-frequency power generated by the high-frequency power generation unit 220 is supplied to the first surface wave exciter 203a via the high-frequency power supply unit 210. Then, the high-frequency power supplied to the first surface wave exciter 203a propagates through the first surface wave exciter 203a with a surface wave to heat the object to be heated 102, and at the same time, the first surface wave exciter 203a A part of the high frequency power propagating by the surface wave is also supplied to the second surface wave exciter 203b arranged at a position facing the first surface wave exciter 203a by spatial coupling. , The second surface wave exciter 203b is propagated by the surface wave to heat the object to be heated 102. Further, in the following, the first surface wave exciter 203a and the second surface wave exciter 203b may be described as the surface wave exciter 203 without particular distinction.

The configurations of the surface wave exciter 203, the high frequency power supply unit 210, and the high frequency power generation unit 220 are the surface wave exciter 103, the high frequency power supply unit 110, and the high frequency as described in the first embodiment. Since the configuration is the same as that of the power generating unit 120, the description thereof will be omitted.

With the above configuration, the high-frequency heating device 200 according to the present embodiment arranges the high-frequency power generated by the high-frequency power generation unit 220 so as to sandwich the object to be heated 102 via the high-frequency power supply unit 210. By supplying only to the first surface wave exciter 203a, which is one of the surface wave exciter 203a and the second surface wave exciter 203b, the first surface wave exciter 203a is supplied. Due to the high frequency power propagating the surface wave exciter 203a and the second surface wave exciter 203b by the surface wave, the cover is installed on the installation table 101 in a simple configuration without using another heat source such as a heater. Both sides of the heated object 102 can be heat-treated, and further, both sides of the heated object 102 can be browned.

Next, the operation of heat-treating the object to be heated 102 of the high-frequency heating device 200 described above will be described.

FIG. 5 shows the first surface wave when the high frequency power generated by the high frequency power generation unit 220 is supplied to the first surface wave exciter 203a shown in FIG. 4 via the high frequency power supply unit 210. High-frequency power propagating by surface waves in the exciter 203a and the second surface wave exciter 203b, respectively, and the strength distribution of the electric field in the vicinity of the surface of the first surface wave exciter 203a and the second surface wave exciter 203b. The state of is schematically shown.

As shown in FIG. 5, when the high frequency power generated by the high frequency power generation unit 220 is supplied to the first surface wave exciter 203a via the high frequency power supply unit 210, the first surface wave exciter 203a is supplied with the surface wave. The high-frequency power 250a propagating in the above forms an electric field distribution 240a in which the electric field is concentrated near the surface of the first surface wave exciter 203a, and the first surface wave exciter 102 is sandwiched by the spatial coupling of radio waves. A part of the high frequency power 250a propagating the first surface wave exciter 203a by the surface wave is supplied to the second surface wave exciter 203b arranged at a position facing the surface wave exciter 203a, and the second surface wave exciter 203a is supplied. The high-frequency power 250b propagating the surface wave exciter 203b by the surface wave forms an electric field distribution 240b in which the electric field is concentrated near the surface of the second surface wave exciter 203b.

As a result, by supplying high-frequency power only to the surface wave exciter on one side of the surface wave exciter 203 arranged at opposite positions so as to sandwich the object to be heated 102, both first surface wave exciters High-frequency power propagates through the 203a and the second surface wave exciter 203b by surface waves, and heat treatment is performed on both sides of the object to be heated 102 installed on the installation table 101 without using another heat source such as a heater. Further, both sides of the object to be heated 102 can be browned.

In particular, when the heater of the conventional example is used, the power consumption is about 800 W to 1000 W when trying to brown the object to be heated, but when the high frequency power generating part in the present invention is used, the power consumption is high. Since it only takes about 100W to 200W, it is also excellent in energy saving performance. Further, in the heater, the surface and the inside of the object to be heated have a hard texture, but when a surface wave exciter is used in the overall configuration in the present invention, the surface of the object to be heated has a hard surface but the inside has a soft finish. It is possible to produce a texture different from that when a heater is used.

Here, in the high-frequency heating device 200 of FIG. 4, the high-frequency power from the high-frequency power generation unit 220 is transmitted to the first surface wave exciter 203a located in the lower surface direction of the object to be heated 102 via the high-frequency power supply unit 210. Although it is described that it is supplied, it may be configured to be supplied to the second surface wave exciter 203b located in the upper surface direction of the object to be heated 102.

(Embodiment 3)
Hereinafter, Embodiment 3 of the present invention will be described with reference to the drawings.

In the description of the third embodiment, the same reference numerals are given to the components having the same functions as those of the first or second embodiment described above, and the description thereof will be omitted. Further, the description of the content having the same operation as that of the first embodiment or the second embodiment described above will be omitted.

FIG. 6 is a block diagram showing the configuration of the high frequency heating device 300 according to the third embodiment of the present invention.

The high frequency heating device 300 shown in the figure is a second surface wave exciter 103a instead of the first surface wave exciter 103a and the second surface wave exciter 103b as compared with the high frequency heating device 100 according to the first embodiment shown in FIG. The surface wave exciter 303a and the second surface wave exciter 303b are provided, and the first high frequency power supply unit 310a and the second high frequency power supply unit 310a and the second high frequency power supply unit 310a replace the first high frequency power supply unit 110a and the second high frequency power supply unit 110b. A high-frequency power supply unit 310b is provided, and a first high-frequency power generation unit 320a and a second high-frequency power generation unit 320b are provided in place of the high-frequency power generation unit 120. In FIG. 6, the high-frequency heating device 300 has two surface wave exciters, two high-frequency power supply units, and two high-frequency power generators. The surface wave exciter and the high-frequency power supply unit And the number of high frequency power generators is not limited to this.

The high-frequency power generated by the first high-frequency power generation unit 320a is supplied to the first surface wave exciter 303a via the first high-frequency power supply unit 310a. Then, the high-frequency power supplied to the first surface wave exciter 303a propagates through the first surface wave exciter 303a by the surface wave to heat the object to be heated 102, and at the same time, the first surface wave exciter 303a A part of the high-frequency power propagating by the surface wave is also supplied to the second surface wave exciter 303b arranged at a position facing the first surface wave exciter 303a by spatial coupling. , The second surface wave exciter 303b is propagated by the surface wave to heat the object to be heated 102.

On the other hand, the high-frequency power generated by the second high-frequency power generation unit 320b is supplied to the second surface wave exciter 303b via the second high-frequency power supply unit 310b. Then, the high-frequency power supplied to the second surface wave exciter 303b propagates through the second surface wave exciter 303b by the surface wave to heat the object to be heated 102, and at the same time, the second surface wave exciter 303b A part of the high-frequency power propagating by the surface wave is also supplied to the first surface wave exciter 303a arranged at a position facing the second surface wave exciter 303b by spatial coupling. , The first surface wave exciter 303a is propagated by a surface wave to heat the object to be heated 102.

Further, in the following, the first surface wave exciter 303a, the second surface wave exciter 303b, the first high frequency power supply unit 310a, the second high frequency power supply unit 310b, and the first high frequency power generation unit The 320a and the second high-frequency power generation unit 320b are not particularly distinguished, and may be described as a surface wave exciter 303, a high-frequency power supply unit 310, and a high-frequency power generation unit 320.

The configurations of the surface wave exciter 303, the high frequency power supply unit 310, and the high frequency power generation unit 320 are the surface wave exciter 103, the high frequency power supply unit 110, and the high frequency as described in the first embodiment. Since the configuration is the same as that of the power generating unit 120, the description thereof will be omitted.

With the above configuration, the high frequency heating device 300 according to the present embodiment arranges the first surface wave exciter 303a and the second surface wave exciter 303b at opposite positions so as to sandwich the object to be heated 102. Then, the high-frequency power generated by the first high-frequency power generation unit 320a is supplied to the first surface wave exciter 303a via the first high-frequency power supply unit 310a, and the second high-frequency power generation unit is used. By supplying the high frequency power generated by the 320b to the second surface wave exciter 303b via the second high frequency power supply unit 310b, the first surface wave exciter 303a and the second surface wave exciter are excited. With high-frequency power propagating through the body 303b by surface waves, it is possible to heat-treat both sides of the object to be heated 102 installed on the installation table 101 without using another heat source such as a heater. It is also possible to brown both sides of the heated object 102.

Next, the operation of heat-treating the object to be heated 102 of the above-mentioned high-frequency heating device 300 will be described.

FIG. 7 is generated in the first surface wave exciter 303a and the second surface wave exciter 303b shown in FIG. 6 by the first high frequency power generating unit 320a and the second high frequency power generating unit 320b. The surface of the first surface wave exciter 303a and the second surface wave exciter 303b when the high frequency power is supplied via the first high frequency power supply unit 310a and the second high frequency power supply unit 310b, respectively. It schematically shows the state of the high frequency power propagated by the wave and the intensity distribution of the electric field in the vicinity of the surface of the first surface wave exciter 303a and the second surface wave exciter 303b.

As shown in FIG. 7, when the high-frequency power generated by the first high-frequency power generation unit 320a is supplied to the first surface wave exciter 303a via the first high-frequency power supply unit 310a, the above-described implementation is performed. Similar to the second embodiment, the high frequency power 350a propagating the first surface wave exciter 303a by the surface wave forms an electric field distribution in which the electric field is concentrated near the surface of the first surface wave exciter 303a, and the radio wave. A part of the high frequency power 350a propagating the first surface wave exciter 303a by the surface wave is also supplied to the second surface wave exciter 303b by the spatial coupling of the above, and the second surface wave exciter 303b is surfaced. The high-frequency power 350b propagated by the wave forms an electric field distribution in which the electric field is concentrated near the surface of the second surface wave exciter 303b.

Similarly, when the high frequency power generated by the second high frequency power generation unit 320b is supplied to the second surface wave exciter 303b via the second high frequency power supply unit 310b, the second surface wave exciter 303b The high-frequency power 350c propagating by the surface wave forms an electric field distribution in which the electric field is concentrated near the surface of the second surface wave exciter 303b, and the spatial coupling of the radio waves causes the first surface wave exciter 303a. Also, a part of the high frequency power 350c propagating the second surface wave exciter 303b by the surface wave is supplied, and the high frequency power 350d propagating the first surface wave exciter 303a by the surface wave causes the first surface wave. An electric field distribution in which the electric field is concentrated is also formed near the surface of the exciter 303a.

Therefore, the high-frequency power 351a propagating the first surface wave exciter 303a by the surface wave is spatially coupled to the high-frequency power 350a supplied from the first high-frequency power generator 320a and the second surface wave exciter 303b. It is the sum of the supplied high frequency power 350d, and the electric field distribution 343a near the surface of the first surface wave exciter 303a is also the electric field strength distribution formed by the high frequency power 350a supplied from the first high frequency power generating unit 320a. And the second surface wave exciter 3
It is formed as a sum of the electric field strength distribution formed by the high frequency power 350d supplied from 03b by spatial coupling.

Similarly, the high-frequency power 351b propagating the second surface wave exciter 303b by the surface wave is spatially coupled to the high-frequency power 350c supplied from the second high-frequency power generator 320b and from the first surface wave exciter 303a. The electric field distribution 343b near the surface of the second surface wave exciter 303b is also the sum of the high frequency power 350b supplied by the second surface wave exciter 303b, and the electric field strength formed by the high frequency power 350c supplied from the second high frequency power generating unit 320b. It is formed as the sum of the distribution and the electric field strength distribution formed by the high frequency power 350b supplied from the first surface wave exciter 303a by spatial coupling.

As a result, high-frequency power is supplied to each of the first surface wave exciter 303a and the second surface wave exciter 303b arranged at positions facing each other so as to sandwich the object to be heated 102, thereby causing the first surface wave excitation. Since the balance state of the high frequency powers 351a and 351b propagating by the surface wave in both the body 303a and the second surface wave exciter 303b can be changed, the heating unevenness and the heating degree can be changed, and the installation table 101 can be changed. A variety of well-balanced heat treatments can be applied to both sides of the object to be heated 102 installed in the above, and further, both sides of the object to be heated 102 can be browned.

Here, in the high-frequency heating device 300 of FIG. 6, the first high-frequency power supply unit 310a and the second high-frequency power supply unit 310b are relative to the first surface wave exciter 303a and the second surface wave exciter 303b. Is provided in the same direction to supply high-frequency power from the first high-frequency power generating unit 320a and the second high-frequency power generating unit 320b from the same direction, but the surface wave exciters 303a and 303b, respectively. The direction of supplying the high frequency power to is not limited to the opposite direction or any other direction.

Further, the high frequency heating device 100 of the first embodiment shown in FIG. 1, the high frequency heating device 200 of the second embodiment shown in FIG. 4, and the high frequency heating device 300 of the third embodiment shown in FIG. 6 are not shown. However, the high frequency power generation units 120, 220, 320a and 320b may be frequency variable high frequency oscillators that generate high frequency power of a set frequency.

A frequency-variable high-frequency oscillator can be realized by using a voltage-variable element (for example, a voltage controller diode) as an element that determines the resonance frequency of the resonance circuit constituting the semiconductor oscillation circuit described above, and is generally VCO (Voltage Controlled). It is called Oscillator). Since the VCO technology is known, detailed description thereof will be omitted. In this case, the frequency can be changed by supplying the voltage information corresponding to the frequency to the VCO by providing a control unit or the like.

Further, a PLL (Phase Locked Loop) oscillator including a reference signal generator and a phase comparator may be configured. Since the technology of the PLL oscillator is known, detailed description thereof will be omitted. In this case, the frequency can be changed by supplying an information signal corresponding to the frequency to the phase comparator by providing a control unit or the like.

By changing the frequency of the high-frequency power supplied to the surface wave exciter, the intensity distribution of the electric field formed near the surface of the surface wave exciter can be changed.

FIG. 8 is a diagram showing a change in the surface concentration of an electric field formed in the vicinity of the surface of the surface wave exciter when the frequency of the high frequency power supplied to the surface wave exciter is changed. The figure graphically shows the magnitude of the electric field strength with respect to the distance from the surface of the surface wave exciter in the relationship between the frequency of the high frequency power supplied to the surface wave exciter and the excitation frequency of the surface wave exciter. The horizontal axis shows the distance from the surface of the surface wave exciter, and the vertical axis shows the magnitude of the electric field strength. The larger the slope of the graph, the more the electric field is concentrated on the surface of the surface wave exciter. Means.

FIG. 8A shows the electric field strength with respect to the distance from the surface of the surface wave exciter when the frequency (fp) of the high frequency power supplied to the surface wave exciter is lower than the excitation frequency (fc) of the surface wave exciter. 8 (b) shows the surface wave exciter when the frequency (fp) of the high frequency power supplied to the surface wave exciter is substantially equal to the excitation frequency (fc) of the surface wave exciter. FIG. 8 (c) shows a graph 402 of the magnitude of the electric field strength with respect to the distance from the surface of the surface wave exciter, in which the frequency (fp) of the high frequency power supplied to the surface wave exciter is higher than the excitation frequency (fc) of the surface wave exciter. Graphs 403 of the magnitude of the electric field strength with respect to the distance from the surface of the surface wave exciter at high time are shown respectively.

As shown in FIG. 8 (b), when the frequency (fp) of the high-frequency power supplied to the surface wave exciter is set to a frequency substantially equal to the excitation frequency (fc) of the surface wave exciter, the surface wave exciter is transmitted from the surface. The slope of the graph 402 of the magnitude of the electric field strength with respect to the distance is the largest, and the electric field is most concentrated on the surface of the surface wave exciter, that is, the electric field strength near the surface of the surface wave exciter is very large, and the surface wave exciter Since the electric field strength decreases sharply as the distance from the surface of the object is increased, it is suitable for intensively heating the surface of the object to be heated to brown it.

Further, as shown in FIG. 8A, when the frequency (fp) of the high frequency power supplied to the surface wave exciter is set to a frequency lower than the excitation frequency (fc) of the surface wave exciter, the surface of the surface wave exciter The slope of the graph 401 of the magnitude of the electric field strength with respect to the distance becomes gentle, and the degree of concentration of the electric field on the surface of the surface wave exciter becomes small, that is, the electric field strength near the surface of the surface wave exciter is large. There is no sudden decrease in electric field strength even when moving away from the surface of the surface wave exciter, and high-frequency power reaches a place slightly away from the surface of the surface wave exciter, so it is suitable for heating the object to be heated so strongly that it does not burn. ing.

Further, as shown in FIG. 8 (c), when the frequency (fp) of the high-frequency power supplied to the surface wave exciter is set to a frequency higher than the excitation frequency (fc) of the surface wave exciter, the surface of the surface wave exciter The slope of the graph 403 of the magnitude of the electric field strength with respect to the distance becomes almost zero, and the electric field is not concentrated on the surface of the surface wave exciter at all, that is, the high frequency power supplied to the surface wave exciter is the surface wave exciter. Since it means a state in which the body is radiated into space without being propagated by surface waves, it is suitable for heating the entire object to be heated relatively evenly.

As described above, the high frequency power generation unit 120 in the high frequency heating device 100 of the first embodiment shown in FIG. 1, the high frequency power generation unit 220 in the high frequency heating device 200 of the second embodiment shown in FIG. 4, and FIG. By using a frequency-variable high-frequency oscillator for the first high-frequency power generation unit 320a and the second high-frequency power generation unit 320b in the high-frequency heating device 300 of the third embodiment shown in the above, the heating pattern can be freely changed. It is possible to heat-treat both sides of the object to be heated 102 installed on the installation table 101 with various finishes, and further, it is possible to give an appropriate browning.

The high-frequency heating device according to the first to third embodiments may have the same basic configuration as a general microwave oven for cooking. That is, a heating chamber for heating the object to be heated is provided inside the substantially rectangular housing, and a high-frequency power generating portion composed of a magnetron or the like for supplying high-frequency power to the heating chamber is provided at the lower part of the housing or the side of the housing. A waveguide for supplying microwaves from the high-frequency power generating unit to the heating chamber is further provided, a surface wave exciter as a heating portion is provided at the lower part, the back or the upper part of the heating chamber, and further, for opening and closing the heating chamber. The overall structure may be such that the door is installed on the front surface of the housing and a door choke groove is provided around the door to prevent electromagnetic wave leakage.

The high-frequency heating device according to the present invention has been described above based on each embodiment, but the present invention is not limited to this embodiment. As long as the gist of the present invention is not deviated, various modifications that can be conceived by those skilled in the art are applied to the embodiment, and a form constructed by combining components in different embodiments is also included in the scope of the present invention. ..

The present invention is a high-frequency heating device that heat-treats an object to be heated by supplying high-frequency power to a surface wave exciter with a simple structure, and can cover both sides of the object to be heated without using another heat source such as a heater. Since it can be heat-treated and can be browned, it is useful as a cooking appliance such as a microwave heater.

100, 200, 300 High frequency heating device 101 Installation stand 102 Heated object 103a, 203a, 303a First surface wave exciter 103b, 203b, 303b Second surface wave exciter 110 High frequency power supply unit 110a, 310a First High frequency power supply unit 110b, 310b Second high frequency power supply unit 120, 220 High frequency power generation unit 130 Square waveguide 131 Tapered square waveguide 140a, 140b, 140c, 240a, 240b, 343a, 343b Electric field strength distribution 210 High frequency power supply unit 250a, 250b High frequency power 320 High frequency power generation unit 320a First high frequency power generation unit 320b Second high frequency power generation unit 350a, 350b, 350c, 350d, 351a, 351b High frequency power

Claims (3)

A high-frequency power generator that generates high-frequency power,
A plurality of surface wave exciters that propagate the high-frequency power with surface waves to heat the object to be heated,
A high-frequency power supply unit that supplies the high-frequency power to the surface wave exciter, and
It is equipped with an installation stand on which the object to be heated is installed.
The plurality of surface wave exciters are installed at positions facing each other so as to sandwich the object to be heated .
The high-frequency power is supplied from the high-frequency power generator only to one of the surface wave exciters.
High-frequency power propagates from one surface wave exciter to the other surface wave exciter to heat the object to be heated.
High frequency heating device. The high-frequency heating device according to claim 1, wherein the high-frequency power is supplied from the high-frequency power generating unit to each of the plurality of surface wave exciters. The high-frequency heating device according to any one of claims 1 or 2 , wherein the high-frequency power generating unit is a frequency-variable high-frequency oscillator that generates high-frequency power of a set frequency.

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