JP6956326B2 - High frequency heating device - Google Patents

Description

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

Conventionally, 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 has been disclosed (see, for example, Patent Document 1).

The high-frequency heating device of Patent Document 1 includes an impedance variable portion that temporally changes the impedance of the terminal portion of the cross-finger type tape line (surface wave line). The impedance variable portion changes the standing wave distribution with time to move the portion that emits strong energy. As a result, the entire food is efficiently heated.

That is, the high-frequency heating device changes the standing wave distribution of the cross-finger tape line (surface wave line) by changing the impedance of the end of the cross-finger tape line (surface wave line), and changes the standing wave distribution of the end. Change the impedance over time. As a result, the standing wave distribution is changed over time to heat the entire food.

However, the conventional high-frequency heating device cannot change the radiation distribution of high-frequency power in the thickness direction of the object to be heated.

Japanese Unexamined Patent Publication No. 61-240589

The present invention provides a high-frequency heating device capable of changing the heating state of the heated portion by changing the radiation distribution of high-frequency power to the object to be heated.

That is, the high-frequency heating device of the present invention uses a high-frequency power generator that generates high-frequency power, a surface wave exciter that propagates high-frequency power by surface waves to heat an object to be heated, and a surface wave exciter that uses high-frequency power as a surface wave exciter. It is equipped with a high-frequency power supply unit to be supplied and an installation stand on which an object to be heated is installed. The high-frequency power generator selects the magnitude relationship between the frequency of the high-frequency power supplied to the surface wave exciter and the excitation frequency of the surface wave exciter according to the surface concentration of the high-frequency power near the desired surface wave exciter. Then, the frequency of the high frequency power supplied to the surface wave exciter is set, and the object to be heated is heat-treated.

According to this configuration, the magnitude relationship between the frequency of the high-frequency power supplied to the surface wave exciter and the excitation frequency of the surface wave exciter is set according to the desired heating state in the thickness direction of the object to be heated. .. Thereby, the object to be heated can be heat-treated in a desired heating state in the thickness direction of the object to be heated.

FIG. 1 is a block diagram showing a basic configuration of the high-frequency heating device of the present embodiment. FIG. 2 is a block diagram showing a configuration of a high-frequency power supply unit of the high-frequency heating device. FIG. 3A is a diagram showing an example of a heating operation of the object to be heated when the surface concentration of the electric field by the surface wave exciter of the high frequency heating device is high. FIG. 3B is a diagram showing an example of a heating operation of the object to be heated when the surface concentration of the electric field by the surface wave exciter of the high frequency heating device is low. FIG. 4A is a graph showing an example of a change in the surface concentration of the electric field with respect to the distance from the surface wave exciter when the frequency of the high frequency power of the high frequency heating device and the excitation frequency of the surface wave exciter are equal. FIG. 4B is a graph showing an example of a change in the surface concentration of the electric field with respect to the distance from the surface wave exciter when the frequency of the high frequency power of the high frequency heating device is lower than the excitation frequency of the surface wave exciter. FIG. 4C is a graph showing an example of a change in the surface concentration of the electric field with respect to the distance from the surface wave exciter when the frequency of the high frequency power of the high frequency heating device is higher than the excitation frequency of the surface wave exciter.

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

(Embodiment)
Hereinafter, the high frequency heating device 100 according to the present embodiment will be described with reference to FIG.

FIG. 1 is a block diagram showing a basic configuration of the high frequency heating device 100 of the present embodiment.

As shown in FIG. 1, the high-frequency heating device 100 includes a surface wave exciter 103, a high-frequency power supply unit 110, a high-frequency power generation unit 120, an installation table 101 on which an object to be heated 102 is placed, and the like. The high-frequency heating device 100 heat-treats the object to be heated 102 installed on the installation table 101.

At this time, the high-frequency heating device 100 is set so that the frequency of the high-frequency power generated by the high-frequency power generation unit 120 and the excitation frequency of the surface wave exciter 103 have a relationship of frequencies intended in advance with each other. .. The intended frequency relationship is set so that the object to be heated 102 is heat-treated in a desired heating state.

The high-frequency heating device 100 shown in FIG. 1 is illustrated by taking as an example a configuration having one surface wave exciter, a high-frequency power supply unit, and a high-frequency power generation unit, but the present invention is not limited to this. The number of surface wave exciters, high-frequency power supply units, and high-frequency power generation units is not limited to the above numbers.

Then, the high frequency heating device 100 operates as follows.

First, the high-frequency power generation unit 120 generates high-frequency power. The generated high-frequency power is supplied to the surface wave exciter 103 via the high-frequency power supply unit 110. The supplied high-frequency power is propagated or radiated by the surface wave in the vicinity of the surface wave exciter 103. As a result, the object to be heated 102 placed on the installation table 101 is heated.

As described above, the high frequency heating device 100 of the present embodiment is configured and operates.

The high-frequency power generation unit 120 is composed of a high-frequency transmitter that outputs high-frequency power having a frequency (for example, microwave) and power suitable for heat treatment of the object to be heated 102.

Specifically, the high-frequency transmitter is composed of, for example, a magnetron and an inverter power supply circuit, a solid-state oscillator and a power amplifier, and the like.

A magnetron is a type of oscillating vacuum tube that generates powerful 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. A high voltage of several kilovolts is required to drive the magnetron. Therefore, an inverter power supply circuit is generally used as a drive power source for the magnetron. The inverter power supply circuit is 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. The inverter power supply circuit is a technology widely used for lighting devices and motor control.

On the other hand, a solid-state oscillator is composed of a transistor and a semiconductor oscillator circuit including a feedback circuit having high-frequency electronic components such as a capacitor, an inductor, and a resistor. The solid-state oscillator is a technology widely used for oscillators for low power output applications such as communication equipment.

In recent years, solid-state oscillators include oscillators that output high-frequency power of about 50 watts, but generally are oscillators that output high-frequency power of about several tens of milliwatts to several hundreds of milliwatts. Therefore, it cannot be used for heat treatment applications that require an output power of several hundred watts. Therefore, a solid-state oscillator is usually used together with a power amplifier composed of a transistor or the like that amplifies the output high-frequency power.

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 composed of a metal periodic structure in which impedance elements are periodically arranged on a metal plate, a dielectric plate, and the like. In the case of a metal periodic structure, for example, a stub type surface wave exciter or an interdigital type surface wave exciter is used. The stub-type surface wave exciter is formed on a metal flat plate as shown in FIG. 1 by arranging a plurality of metal flat plates at regular intervals in a direction in which they stand toward an object to be heated. The interdigital surface wave exciter is formed by punching a metal flat plate in a cross-finger shape. As the dielectric plate, an alumina plate or a bakelite plate is used.

At this time, the excitation frequency of the surface wave exciter 103 is determined by the material used, the physical structural dimensions, and the like. For example, in the case of a stub type surface wave exciter, the excitation frequency of the surface wave exciter 103 is 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. Can be made to. Normally, the excitation frequency of the surface wave exciter 103 increases as the height dimension of the metal flat plate is lowered, and becomes higher as the space dimension of the metal flat plate is reduced. Therefore, the surface wave exciter 103 having a desired excitation frequency can be formed by adjusting the height and spacing of the metal flat plates.

Further, the surface wave exciter 103 concentrates the high frequency power supplied from the high frequency power generation unit 120 via the high frequency power supply unit 110 in the vicinity of the surface and propagates it by the surface wave. Further, the surface wave exciter 103 can also radiate high frequency power into, for example, the space inside the high frequency heating device 100. As a result, the object to be heated 102 placed on the installation table 101 in the vicinity of the surface wave exciter 103 propagates in the vicinity of the surface of the surface wave exciter 103 with a surface wave, or has a high frequency radiated from the surface wave exciter 103. It is heated by electric power.

Next, the configuration of the high-frequency power supply unit 110 of the present embodiment will be described with reference to FIG.

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

As shown in FIG. 2, the high-frequency power supply unit 110 is arranged so as to guide the high-frequency power generated by the high-frequency power generation unit 120 to the high-frequency power supply unit 110 via the rectangular waveguide 130.

The square waveguide 130 is composed of a hollow waveguide mainly used for transmitting electromagnetic waves such as microwaves. The hollow waveguide is a general waveguide, and is formed of a metal tube having a rectangular (for example, rectangular) cross-sectional shape. The electromagnetic wave propagates in the rectangular waveguide 130 while forming an electromagnetic field according to the shape, size, wavelength or frequency of the rectangular waveguide 130.

Then, the high-frequency power propagated from the high-frequency power generation unit 120 is supplied to the surface wave exciter 103 via the rectangular waveguide 130 and the tapered rectangular waveguide 131. The tapered rectangular waveguide 131 suppresses reflection of propagating microwaves at the junction to reduce loss.

That is, as shown by the broken line in FIG. 2, the high-frequency power supply unit 110 includes a part of the square waveguide 130, a tapered square waveguide 131, and a part of the surface wave exciter 103. NS.

As a result, the high-frequency power generated by the high-frequency power generation unit 120 is guided to the high-frequency power supply unit 110 via the square waveguide 130, and the surface wave exciter via the tapered square waveguide 131. It is efficiently supplied to 103.

At this time, in the high-frequency heating device 100 of the present embodiment, the frequency of the high-frequency power generated by the high-frequency power generation unit 120 and the excitation frequency of the surface wave exciter 103 have a relationship of frequencies intended in advance with each other. Is set. As a result, as will be described later, the object to be heated 102 is heat-treated in a desired heating state.

As described above, the high-frequency heating device 100 of the present embodiment is configured, and the object to be heated 102 and the like are heat-treated.

Next, the operation of heat-treating the object to be heated 102 of the high-frequency heating device 100 described above will be described with reference to FIGS. 3A and 3B.

3A and 3B show an operation of heating the object to be heated 102 with an electric field strength distribution near the surface of the surface wave exciter 103 by the supplied high frequency power in a state where the object to be heated 102 is installed on the installation table 101. An example is schematically shown.

That is, FIG. 3A shows a surface wave exciter when the frequency of the high frequency power generated by the high frequency power generating unit 120 and the excitation frequency of the surface wave exciter 103 are set so that the surface concentration of the high frequency power becomes high. The electric field strength distribution 141 formed near the surface of 103 is shown.

FIG. 3B shows an electric field strength distribution 142 formed in the vicinity of the surface of the surface wave exciter 103 when the frequency of the high frequency power and the excitation frequency are set so that the surface concentration of the high frequency power is low.

In addition, in FIG. 3A and FIG. 3B, the electric field strength of the electric field strength distributions 141 and 142 is represented by the shade of color. In this case, the darker the color, the stronger the electric field.

In the case of FIG. 3A, the relationship between the frequency of the high frequency power and the excitation frequency of the surface wave exciter 103 is set so that the surface concentration of the high frequency power becomes high in the vicinity of the surface wave exciter 103. Therefore, the electric field strength near the surface of the surface wave exciter 103 becomes stronger. As a result, the surface of the object to be heated 102 on the side close to the surface wave exciter 103 and the inside on the side close to the surface wave exciter 103 are intensively and strongly heated. Then, as the distance from the surface wave exciter 103 increases, the electric field strength sharply weakens. Therefore, the degree of heating of the object to be heated 102 is also weakened.

On the other hand, in the case of FIG. 3B, the relationship between the frequency of the high frequency power and the excitation frequency of the surface wave exciter 103 is set so that the surface concentration of the high frequency power becomes low in the vicinity of the surface wave exciter 103. In this case, the electric field strength in the vicinity of the surface of the surface wave exciter 103 is weakened, but the decrease in the electric field strength is small even when the surface wave exciter 103 is separated from the surface. Therefore, the surface of the object to be heated 102 on the side in contact with the surface wave exciter 103 is not intensively and strongly heated. That is, the entire object 102 to be heated is heated relatively evenly.

As described above, the high-frequency heating device 100 executes the heat treatment operation of the object to be heated 102 based on the relationship between the frequency of the high-frequency power and the excitation frequency of the surface wave exciter 103.

Hereinafter, with reference to FIGS. 3A and 3B, the relationship between the distance from the surface of the surface wave exciter 103 and the electric field strength based on the magnitude relationship between the frequency of the high frequency power and the excitation frequency of the surface wave exciter 103 described above. However, it will be described with reference to FIGS. 4A to 4C.

4A to 4C show high-frequency power formed in the vicinity of the surface of the surface wave exciter 103 due to the relationship between the frequency fp of the high-frequency power supplied to the surface wave exciter 103 and the excitation frequency fc of the surface wave exciter 103. An example of the change in the surface concentration of (electric field) is schematically shown.

Specifically, FIGS. 4A to 4C show the distance from the surface of the surface wave exciter 103 in the relationship between the frequency fp of the high frequency power supplied to the surface wave exciter 103 and the excitation frequency fc of the surface wave exciter 103. The change in the magnitude of the electric field strength with respect to is shown in a graph. At this time, the horizontal axis of FIGS. 4A to 4C indicates the distance from the surface of the surface wave exciter, and the vertical axis indicates the magnitude of the electric field strength. In the figure, the larger the slope of the graph, the more the electric field is concentrated on the surface of the surface wave exciter 103.

FIG. 4A shows the magnitude of the electric field strength with respect to the distance from the surface of the surface wave exciter 103 when the frequency fp of the high frequency power supplied to the surface wave exciter 103 is substantially equal to the excitation frequency fc of the surface wave exciter 103. It is shown in graph 151. FIG. 4B is a graph 152 showing the magnitude of the electric field strength when the frequency fp of the high-frequency power is lower than the excitation frequency fc. Further, FIG. 4C is a graph 153 showing the magnitude of the electric field strength when the frequency fp of the high frequency power is higher than the excitation frequency fc.

First, as shown in FIG. 4A, when the frequency fp of the high-frequency power and the excitation frequency fc are set to substantially the same frequency, the magnitude of the electric field strength with respect to the distance from the surface of the surface wave exciter 103 is shown in Graph 151. The slope is the largest. That is, the electric field is strongly concentrated near the surface of the surface wave exciter 103, which is similar to FIG. 3A. As a result, the surface of the object to be heated 102 is intensively heated. Therefore, the relationship between the frequency fp and the excitation frequency fc is suitable for browning the surface of the object to be heated 102.

Further, as shown in FIG. 4B, when the frequency fp of the high frequency power is set to a frequency lower than the excitation frequency fc, the inclination of the graph 152 becomes gentler than the inclination of the graph 151 of FIG. 4A. That is, the degree of concentration of the electric field on the surface of the surface wave exciter 103 decreases, and the distance that the high frequency power reaches from the surface of the surface wave exciter 103 becomes long. Therefore, although the electric field strength near the surface of the surface wave exciter 103 is relatively large, there is no sudden decrease in the electric field strength even when the surface wave exciter 103 is moved away from the surface. That is, the high frequency power reaches a place slightly away from the surface of the surface wave exciter 103. Therefore, the relationship between the frequency fp and the excitation frequency fc is suitable for heating the object to be heated 102 so strongly that it does not burn.

Further, as shown in FIG. 4C, when the frequency fp of the high frequency power is set to a frequency higher than the excitation frequency fc, the inclination of the graph 153 is almost eliminated and the electric field strength distribution becomes flat. That is, the electric field does not concentrate near the surface of the surface wave exciter 103, but spreads and distributes over the entire surface. This means that the high-frequency power supplied to the surface wave exciter 103 is radiated into space without propagating the surface wave exciter 103 with the surface wave. Therefore, the relationship between the frequency fp and the excitation frequency fc is suitable for heating the entire object 102 to be heated relatively evenly.

As described above, the high-frequency heating device 100 of the present embodiment is attached to the surface wave-exciting body 103 according to the surface concentration of high-frequency power in the vicinity of the surface of the surface wave-exciting body 103 corresponding to the heating state desired by the user. The magnitude relationship between the frequency fp of the high frequency power to be supplied and the excitation frequency fc of the surface wave exciter 103 is set. As a result, it is possible to change the propagation state of the high-frequency power propagating in the surface wave exciter 103 by the surface wave. Then, the electric field strength distribution near the surface of the surface wave exciter 103 changes. As a result, the object to be heated 102 can be heat-treated in the heating state desired by the user.

That is, the relationship between the frequency fp and the excitation frequency fc is set so that the frequency fp of the high frequency power supplied to the surface wave exciter 103 is equal to or lower than the excitation frequency fc of the surface wave exciter 103. In this case, the high frequency power supplied to the surface wave exciter 103 propagates on the surface wave exciter 103 as a surface wave. That is, the high frequency power propagates in the operation in the "surface wave mode". At this time, by adjusting the low adjustment (difference) of the frequency fp of the high frequency power with respect to the excitation frequency fc of the surface wave exciter 103, the surface concentration of the high frequency power propagating by the surface wave of the surface wave exciter 103 can be adjusted. .. As a result, the object to be heated 102 can be optimally heat-treated according to the heating state in the thickness direction of the object to be heated desired by the user.

On the other hand, the relationship between the frequency fp and the excitation frequency fc is set so that the frequency fp of the high frequency power supplied to the surface wave exciter 103 is higher than the excitation frequency fc of the surface wave exciter 103. In this case, the high-frequency power supplied to the surface wave exciter 103 is radiated into space without propagating the surface wave exciter 103 with the surface wave. That is, the high frequency power is radiated by the operation in the "radiation mode". Therefore, the entire object to be heated 102 can be heated relatively evenly.

In the above embodiment, the configuration in which the high-frequency power generation unit 120 of the high-frequency heating device 100 generates high-frequency power at a fixed frequency fp has been described as an example, but the present invention is not limited to this. For example, the high-frequency power generator 120 may be configured with a high-frequency transmitter having a variable frequency so as to 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 ballactor diode) as an element for determining the resonance frequency of the resonance circuit constituting the semiconductor oscillation circuit described above. A high frequency oscillator with variable frequency is generally called a VCO (Voltage Control Oscillator). Since the VCO technology is known, detailed description thereof will be omitted. In this case, a control unit is provided in the high frequency oscillator, and voltage information corresponding to the frequency is supplied to the VCO. This makes it possible to change the frequency of the high frequency oscillator.

Further, the frequency-variable high-frequency oscillator may be configured by a PLL (Phase Locked Loop) oscillator including a reference signal generator and a phase comparator. Since the technology of the PLL oscillator is known, detailed description thereof will be omitted. In this case, a control unit is provided in the PLL oscillator, and an information signal corresponding to the frequency is supplied to the phase comparator. As a result, the frequency of the PLL oscillator can be changed.

As a result, one high-frequency power generating unit can generate high-frequency power of a plurality of frequencies. Therefore, the magnitude relationship between the frequency fp of the high-frequency power supplied to the surface wave exciter 103 and the excitation frequency fc of the surface wave exciter 103 described above can be easily and freely set. That is, the magnitude relationship between the frequency fp of the high-frequency power supplied to the surface wave exciter 103 and the excitation frequency fc of the surface wave exciter 103 can be freely changed. Thereby, with a simple configuration, the heated object 102 can be heat-treated by changing the heating state in the thickness direction of the object to be heated 102 as desired by the user.

Further, in the high frequency heating device 100 of the present embodiment, the surface wave exciter 103 may be composed of a surface wave exciter with a variable excitation frequency capable of varying the excitation frequency.

Specifically, when the surface wave exciter is formed by the above-mentioned stub type surface wave exciter, a dielectric material is mechanically controlled between the metal plates arranged at regular intervals on the metal flat plate. To insert. Thereby, the excitation frequency of the surface wave exciter can be changed.

In this case, the excitation frequency of the surface wave exciter may be changed by changing the dielectric constant of the dielectric by electrical control instead of mechanical control. Thereby, the excitation frequency of the surface wave exciter can be changed relatively greatly. Therefore, the heating state in the thickness direction of the object to be heated can be significantly changed. As a result, the range of the heated state desired by the user can be expanded, and the object to be heated can be heat-treated in various ways.

In the above embodiment, the use of the high-frequency heating device is not particularly mentioned, but for example, the basic configuration may be the same as that of a general cooking microwave oven described below.

That is, the microwave oven is composed of at least a heating chamber, a high-frequency power generating unit, a waveguide, a surface wave exciter constituting the heating unit, a door, a door choke groove, and the like. The heating chamber is formed in a substantially rectangular parallelepiped shape (including a rectangular parallelepiped shape), and an object to be heated is placed therein. The high-frequency power generator is composed of a magnetron or the like, and supplies high-frequency power to the heating chamber. The high-frequency power generator is provided at the lower part of the housing or the side of the housing. The waveguide supplies microwaves generated by the high-frequency power generator into the heating chamber. The surface wave exciter is provided in the lower part, the back part or the upper part of the heating chamber, and propagates high frequency electric power to heat the object to be heated. The door is installed on the front of the housing to open and close the heating chamber. The door choke groove is provided around the door to prevent electromagnetic wave leakage such as microwaves.

The high-frequency heating device according to the present invention has been described above based on the 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 each embodiment, and a form constructed by combining components in different embodiments is also included in the scope of the present invention. ..

As described above, the high-frequency heating device of the present invention uses a high-frequency power generator that generates high-frequency power, a surface wave exciter that propagates high-frequency power by surface waves to heat an object to be heated, and high-frequency power. It is equipped with a high-frequency power supply unit that supplies the surface wave exciter and an installation stand on which the object to be heated is installed. The high-frequency power generator selects the magnitude relationship between the frequency of the high-frequency power supplied to the surface wave exciter and the excitation frequency of the surface wave exciter according to the surface concentration of the high-frequency power near the desired surface wave exciter. Then, the frequency of the high frequency power supplied to the surface wave exciter is set, and the object to be heated is heat-treated.

According to this configuration, the magnitude relationship between the frequency of the high-frequency power supplied to the surface wave exciter and the excitation frequency of the surface wave exciter is set according to the heating state desired by the user in the thickness direction of the object to be heated. do. Thereby, the object to be heated can be heat-treated in a desired heating state in the thickness direction of the object to be heated.

Further, in the high frequency heating device of the present invention, the frequency of the high frequency power supplied to the surface wave exciter may be set equal to the excitation frequency of the surface wave exciter or lower than the excitation frequency of the surface wave exciter.

According to this configuration, the high-frequency power supplied to the surface wave exciter becomes a "surface wave mode" operation in which the surface wave propagates in the vicinity of the surface of the surface wave exciter. As a result, the side of the object to be heated near the surface wave exciter can be concentrated and heated.

Further, in the high frequency heating device of the present invention, the frequency of the high frequency power supplied to the surface wave exciter may be set higher than the excitation frequency of the surface wave exciter.

According to this configuration, the high-frequency power supplied to the surface wave exciter does not propagate in the vicinity of the surface of the surface wave exciter by the surface wave, but is radiated into the space in the “radiation mode” operation. As a result, the entire object to be heated can be heated evenly.

Further, in the high frequency heating device of the present invention, the high frequency power generating unit may be configured by a frequency variable high frequency oscillator that generates high frequency power of a set frequency.

According to this configuration, the frequency of the high frequency power supplied to the surface wave exciter can be changed. Thereby, the frequency of the high frequency power can be arbitrarily set with respect to the excitation frequency of the surface wave exciter. As a result, the electric field intensity distribution formed by the surface wave exciter can be arbitrarily adjusted. Therefore, the object to be heated can be heat-treated in various heating states in the thickness direction of the object to be heated.

Further, in the high frequency heating device of the present invention, the surface wave exciter may be composed of a surface wave exciter having a variable excitation frequency and a variable excitation frequency.

According to this configuration, the excitation frequency of the surface wave exciter can be changed with respect to the frequency of the high frequency power supplied to the surface wave exciter. Thereby, the object to be heated can be heat-treated in various heating states in the thickness direction of the object to be heated.

The present invention is useful for cooking appliances such as microwave heaters, where heat treatment is required in a desired heating state in the thickness direction of the object to be heated.

100 High-frequency heating device 101 Installation stand 102 Heated object 103 Surface wave exciter 110 High-frequency power supply unit 120 High-frequency power generator 130 Square waveguide 131 Tapered square waveguide 141,142 Electric field strength distribution

Claims (5)

A high-frequency power generator that generates high-frequency power,
A surface wave exciter that propagates the high-frequency power with a surface wave 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 high-frequency power generating unit has a frequency of the high-frequency power supplied to the surface wave exciter and an excitation frequency of the surface wave exciter according to the desired surface concentration of the high-frequency power in the vicinity of the surface wave exciter. A high-frequency heating device that heat-treats the object to be heated by selecting the magnitude relationship with and setting the frequency of the high-frequency power supplied to the surface wave exciter. The high-frequency heating device according to claim 1, wherein the frequency of the high-frequency power supplied to the surface wave exciter is equal to the excitation frequency of the surface wave exciter or lower than the excitation frequency of the surface wave exciter. The high-frequency heating device according to claim 1, wherein the frequency of the high-frequency power supplied to the surface wave exciter is higher than the excitation frequency of the surface wave exciter. The high-frequency heating device according to claim 1, wherein the high-frequency power generator is composed of a frequency-variable high-frequency oscillator that generates high-frequency power of a set frequency. The high-frequency heating device according to claim 1, wherein the surface wave exciter is composed of a surface wave exciter having a variable excitation frequency and a variable excitation frequency.

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