JP7178556B2 - High frequency heating device - Google Patents

Description

The present invention relates to a high-frequency heating device having a surface wave transmission line using a periodic structure.

Conventionally, there has been disclosed a technique related to a high-frequency heating apparatus that heats an object to be heated such as food by supplying high-frequency power to a surface wave transmission line using a periodic structure.

For example, in Patent Document 1, high-frequency power is fed from the end of a planar surface wave transmission line, an object to be heated is placed on the surface wave transmission line in the direction in which the surface wave travels, and the surface wave transmission line is heated. A high-frequency thawing heating apparatus is disclosed that heats the underside of the object to be heated using the feature that the side closer to the point is heated more strongly.

Further, in Patent Document 2, a cylindrical metal plate with periodic slot holes is placed in an environment where microwaves are confined in a case of a microwave oven or the like covered with a metal wall. By setting the object to be heated, a waveguide is formed by the metal wall and the cylindrical metal plate, and the surface waves generated in the slot holes provided periodically in the cylindrical metal plate move the object to be heated. Disclosed is a high-frequency heater that can efficiently heat an object to be heated, particularly a round object or a tall object such as a sake bottle, by intensively heating the object.

JP-A-8-166133 Japanese Utility Model Laid-Open No. 57-78597

However, in the conventional configuration shown in Patent Document 1, when the object to be heated is round in shape or has a large height dimension, only the lower side adjacent to the surface wave transmission line is heated. As a result, sufficient heat treatment cannot be applied.

In addition, in the conventional configuration shown in Patent Document 2, it is said that sufficient heat treatment can be performed even when the shape of the object to be heated is round or when the dimension in the height direction is large. A waveguide made of a cylindrical metal plate cannot be formed in an appropriate shape, and the shape of the waveguide changes depending on the size and placement position of the cylindrical metal plate. The surface waves generated in the slot holes periodically provided in the shaped metal plate are unstable, and the power of the surface waves to scorch the surface of the object to be heated cannot be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-frequency heating apparatus capable of sufficiently heat-treating an object to be heated having a round shape or a large height dimension. and

In order to solve the above conventional problems, the high-frequency heating apparatus of the present invention includes at least one surface wave transmission line, at least one high-frequency power generator for generating high-frequency power, and supplying high-frequency power to the surface wave transmission line. and at least one high-frequency power feeder, wherein the surface wave transmission line is configured in a cylindrical shape, and the high-frequency power generated by the high-frequency power generator is supplied to the surface wave transmission line via the high-frequency power feeder. supply power.

With this configuration, the high-frequency power generated by the high-frequency power generator is directly fed to the cylindrical surface wave transmission line through the high-frequency power feeder, so the high-frequency power supplied to the surface wave transmission line is , is efficiently converted into surface wave power propagating in the surface wave transmission line. As a result, even if the object to be heated placed inside the cylindrical surface wave transmission line has a round shape or a shape with a large height dimension, sufficient heat treatment can be performed.

Schematic diagram showing the basic configuration of the high-frequency heating apparatus of Embodiment 1 Schematic diagram showing the configuration of the high-frequency power feeding unit of the first embodiment FIG. 4 is a diagram showing propagation of high-frequency power fed to the surface-wave transmission line of the first embodiment; FIG. 4 is a diagram showing how high-frequency power is radiated from the cylindrical surface wave transmission line of the first embodiment; FIG. 4 is a diagram showing an electric field strength distribution formed in the vicinity of the cylindrical surface wave transmission line of Embodiment 1; Schematic diagram showing a configuration in which a short circuit is provided in the surface wave transmission line of Embodiment 1. FIG. FIG. 2 is a developed view showing high-frequency power propagating through a surface wave transmission line provided with a short-circuited portion according to the first embodiment; Schematic diagram showing the basic configuration of the high-frequency heating apparatus of Embodiment 2 FIG. 10 is a diagram showing how high-frequency power is radiated from the surface-wave transmission line of the second embodiment; FIG. 11 shows an electric field intensity distribution formed near the surface wave transmission line of the second embodiment; Schematic diagram showing the basic configuration of the high-frequency heating apparatus of Embodiment 3 FIG. 10 is an exploded view showing high-frequency power propagating through the surface-wave transmission line of the third embodiment;

A first invention comprises at least one surface wave transmission line, at least one high frequency power generating section for generating high frequency power, and at least one high frequency power feeding section for feeding high frequency power to the surface wave transmission line. The surface wave transmission line is configured in a cylindrical shape, and is configured in a cylindrical shape by feeding high-frequency power generated by the high-frequency power generating section to the surface wave transmission line through the high-frequency power feeding section. A high-frequency power generated by a high-frequency power generator is fed to the surface wave transmission line via the high-frequency power feeder, so that an object to be heated placed inside the tubular surface wave transmission line is heat-treated. , the high-frequency power supplied to the surface-wave transmission line is efficiently converted into surface-wave power propagating through the surface-wave transmission line. As a result, even if the object to be heated installed inside the cylindrical surface wave transmission line has a round shape or a shape with a large height dimension, the surface of the object to be heated can be sufficiently heated such that the surface of the object is scorched in a wide range. Treatment can be stably applied.

In a second aspect of the invention, particularly in the first aspect, the surface wave transmission line has a plate-like periodic structure. , the periodic structure can be easily processed, and can contribute to cost reduction.

In a third aspect of the invention, particularly in the second aspect, the high-frequency power feeding section feeds high-frequency power to the surface wave transmission line by means of an electric field coupling type antenna. The matching with the transmission line is improved, and the efficiency of supplying high frequency power to the surface wave transmission line can be improved.

In a fourth aspect of the invention, since the surface wave transmission line according to any one of the first to third aspects is provided with a short-circuit portion, a high frequency wave propagates through the surface wave transmission line from the high frequency power feeder. The power is almost totally reflected at the short-circuit point and propagates through the surface wave transmission line again in the opposite direction. It is possible to improve the heating efficiency of the object to be heated installed inside the line by the high-frequency power.

In a fifth aspect of the invention, in any one of the first to fourth aspects of the invention, a metal wall is installed outside the surface wave transmission line so as not to contact the surface wave transmission line. The high-frequency power radiated to the outside of the cylindrical surface wave transmission line can be reflected by the metal wall and led to the inside without hindering the propagation of the propagating high-frequency power. It is possible to improve the efficiency of heating the object to be heated by the high-frequency power.

A sixth aspect of the invention is particularly provided with a plurality of the high-frequency power feeding units according to any one of the first to fifth aspects of the invention, wherein the surface wave transmission line has a short circuit between adjacent high-frequency power feeding units. is provided, a plurality of feeding sections can be provided in the cylindrical surface wave transmission line, the heating state can be partially controlled, and the uniformity of heating can be improved.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a schematic diagram showing the basic configuration of a high-frequency heating device 100 according to Embodiment 1 of the present invention. A high-frequency heating apparatus 100 shown in FIG. A power generator 103 and a high-frequency power feeder 110 are provided.

In FIG. 1, the high-frequency heating device 100 has at least one surface wave transmission line, at least one high-frequency power generator, and at least one high-frequency power feeder. The number of power generators and high-frequency power feeders is not limited to this.

High-frequency power generated by high-frequency power generator 103 is fed to surface wave transmission line 101 via high-frequency power feeder 110 .

The high-frequency power generator 103 is a high-frequency oscillator that outputs high-frequency power having a frequency (for example, microwaves of 2.45 GHz) and power suitable for heat-treating the object 102 to be heated. For example, it may be composed of a magnetron and an inverter power supply circuit, or it may be composed of a solid-state oscillator and a power amplifier.

A magnetron is a type of oscillating vacuum tube that generates powerful non-coherent microwaves, a type of radio wave, and is often used for high-power applications of several hundred watts to several kilowatts, such as radar 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 supply for the magnetron. An inverter power supply is a power supply circuit composed of a converter circuit with a rectifying function and an inverter circuit with a step-up (or step-down) function and an output frequency conversion function, and is a technology widely used in lighting equipment and motor control.

Solid-state oscillators, on the other hand, are semiconductor oscillator circuits in which feedback circuits are composed of high-frequency electronic components such as transistors and capacitors, inductors, and resistors, and are widely used in oscillators for low-power output applications such as communication equipment. . High-frequency power output from a solid-state oscillator has a high output of about 50 watts in recent years, but it is generally about tens of milliwatts to hundreds of milliwatts. , the high-frequency power output from the solid-state oscillator is generally amplified by a power amplifier such as a transistor.

The present invention does not limit the configuration of the high-frequency power generation section 103, so detailed description thereof will be omitted.

The high-frequency power feeder 110 corresponds to a power connector that feeds the high-frequency power generated by the high-frequency power generator 103 to the surface wave transmission line 101 . The configuration of high-frequency power feeding section 110 will be described later.

The surface wave transmission line 101 is formed of a metal periodic structure in which impedance elements are periodically arranged on a metal plate, a dielectric plate, or the like. For example, in a metal periodic structure, a stub type surface wave transmission line in which a plurality of metal plates are arranged on a metal plate at regular intervals, or an interdigital type surface wave transmission line in which a metal plate is punched in the shape of interdigitated fingers can be used. An alumina plate or bakelite plate can be used as the dielectric plate. In addition, the surface of the resin plate of the interdigital surface wave transmission line can be plated with a metal film.

The present embodiment shown in FIG. 1 shows an example in which an interdigital surface wave transmission line is formed in a cylindrical shape by punching out a metal flat plate in the shape of interdigitated fingers. By constructing the surface wave transmission line by forming the periodic structure in the form of a plate, the degree of freedom of the cylindrical shape is increased, the processing is facilitated, and the cost can be reduced.

The surface wave transmission line 101 propagates the high frequency power supplied from the high frequency power generation unit 103 via the high frequency power supply unit 110 as a surface wave. An object to be heated 102 placed inside 101 is heated.

Next, the configuration of high-frequency power feeding section 110 will be described with reference to the drawings.

FIG. 2 is a schematic diagram showing an example of the configuration of the high-frequency power feeding section 110. As shown in FIG. FIG. 2(a) shows a plan view, and FIG. 2(b) shows a side sectional view.

In the figure, the high frequency power generated by the high frequency power generator 103 shown in FIG. 1 shows the configuration for the case.

As shown in FIG. 2, the high-frequency power generated by the high-frequency power generating section 103 is guided to the high-frequency power feeding section 110 through the coaxial cable line 111, and the antenna 113 is attached to the core wire 112 of the coaxial cable line 111. The tip of 113 is fixed to surface wave transmission line 101 by bolt 114 . The outer conductor of the coaxial cable line 111 is fixed to a coaxial cable line fixing projection 117 provided on the surface wave transmission line 101 by a coaxial cable line fixture 115 and bolts 116a, 116b, 116c, and 116d. .

With this configuration of high-frequency power feeding section 110 , high-frequency power guided from high-frequency power generating section 103 through coaxial cable line 111 is directly fed to surface wave transmission line 101 via antenna 113 . Here, in FIG. 2, the tip of the antenna 113 is fixed to the surface wave transmission line 101, and the outer skin conductor of the coaxial cable line 111 is fixed to the coaxial cable line fixing protrusion 117 provided on the surface wave transmission line 101. Bolts 114, 116a, 116b, 116c, 116d and coaxial cable wire fixture 115 are used as fixing means, but each fixing means is not limited to this, and the frequency of the high-frequency power used for heating , any method can be used as long as it can reliably maintain continuity. For example, a method such as fixing with a conductive tape or welding may be used.

With the configuration described above, the high-frequency heating apparatus 100 according to the present embodiment supplies the high-frequency power generated by the high-frequency power generation section 103 to the surface wave transmission line 101 configured in a cylindrical shape through the high-frequency power supply section 110. , the high-frequency power supplied to the surface-wave transmission line 101 is efficiently converted into surface-wave power propagating through the surface-wave transmission line 101. Heat treatment such as browning can be applied to the object to be heated 102 placed in the .

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

FIG. 3 is a diagram showing how high-frequency power 120 generated by high-frequency power generator 103 and supplied to surface wave transmission line 101 via high-frequency power feeder 110 propagates along surface wave transmission line 101 . .

As shown in FIG. 3, high-frequency power 120 supplied to surface wave transmission line 101 via high-frequency power feeder 110 is divided into high-frequency powers 121 and 122 propagating in two left and right directions. propagates along the groove of

FIG. 4 shows that when high-frequency power is supplied from a high-frequency power feeder 110 to a cylindrical surface-wave transmission line 101, the high-frequency power propagating through the surface-wave transmission line 101 radiates from the surface of the surface-wave transmission line 101. FIG. 3 is a diagram showing the state of high-frequency power that is applied.

As shown in FIG. 4, the high-frequency power supplied from the high-frequency power feeder 110 is divided into high-frequency powers 123 and 124, which propagate through the surface wave transmission line 101 as surface waves. High-frequency power 123 and 124 propagating through the surface-wave transmission line 101 as surface waves generates high-frequency power 126 that is radiated inside the cylinder from the surface of the surface-wave transmission line 101 , and also radiates outside the cylinder. Radiated RF power 125 is generated. Of these, the object to be heated 102 is heated by the high-frequency power 126 radiated to the inner side of the cylinder.

FIG. 5 is a diagram showing an electric field intensity distribution formed in the vicinity of the cylindrical surface wave transmission line 101 when high frequency power is supplied from the high frequency power supply unit 110 to the surface wave transmission line 101. FIG. is.

As shown in FIG. 5, due to high-frequency power supplied from the high-frequency power feeder 110 and propagating through the surface wave transmission line 101 as surface waves, an electric field intensity distribution 130 on the inside and an electric field on the outside are generated near the surface wave transmission line 101 . An intensity distribution 131 is formed respectively. Here, the electric field strength distributions 130 and 131 shown in the figure indicate the magnitude of the electric field strength by the depth of color, and the darker the color, the greater the magnitude of the electric field strength.

As shown in FIG. 5, the electric field intensity distribution formed in the vicinity of the surface wave transmission line 101 is such that in both the inner electric field intensity distribution 130 and the outer electric field intensity distribution 131, the vicinity of the surface of the surface wave transmission line 101 is The magnitude of the electric field intensity is the largest, and the magnitude of the electric field intensity decreases as the distance from the surface of the surface wave transmission line 101 increases. Furthermore, the electric field strength distribution 131 on the outer side has a lighter color because the high-frequency power radiated from the surface wave transmission line 101 is diffused to the outer space, and the magnitude of the electric field strength decreases as a whole. On the other hand, the electric field intensity distribution 130 on the inner side has a large electric field intensity and a dark color because the high-frequency power radiated from the surface wave transmission line 101 is concentrated toward the center.

That is, it shows that high-frequency power concentrates inside the surface wave transmission line 101 formed in a cylindrical shape. As a result, the electric field intensity distribution 130 formed inside the surface wave transmission line 101 concentrates the high-frequency power on the object to be heated, and heat treatment such as scorching the object to be heated can be performed.

With the configuration as described above, the high-frequency heating apparatus 100 according to the present embodiment applies high-frequency power generated by the high-frequency power generation section 103 to the cylindrical surface wave transmission line 101 through the high-frequency power supply section 110. By supplying power directly, high-frequency power fed to the surface wave transmission line 101 is efficiently converted into surface wave power propagating through the surface wave transmission line 101 . As a result, even if the object to be heated 102 installed inside the cylindrical surface wave transmission line 101 has a round shape or a shape with a large height dimension, sufficient heat treatment such as scorching of the surface can be stably performed. can apply.

Here, as the antenna 113 shown in FIG. 2, an electric field coupling antenna in which electric power is transmitted by an electric field generated when electrodes are close to each other may be used.

As a result, in a surface wave transmission line in which a surface wave is formed and propagated by an electric field generated between flat plate conductors, such as an interdigital type surface wave transmission line composed of flat plate conductors, an electric field coupling type antenna is used as a feeding means. By using it, matching with the surface wave transmission line can be easily achieved, so that the efficiency of conversion to surface wave power can be improved.

In addition, the tubular surface wave transmission line may be provided with a portion that is short-circuited at high frequencies at the frequency of the high frequency power used for the heat treatment.

FIG. 6 shows a state in which the surface wave transmission line 101 in the high frequency heating apparatus 100 shown in FIG. As shown in the figure, the surface wave transmission line 150 is provided with a short-circuit portion 151 that short-circuits at a high frequency at the frequency of the high-frequency power used for the heat treatment at a portion facing the high-frequency power feeding portion 110 . there is

FIG. 7 is an expanded view of the surface wave transmission line 150 shown in FIG. is shown. As shown in the figure, high-frequency power 160 generated by high-frequency power generator 103 and fed to surface wave transmission line 150 via high-frequency power feeder 110 propagates rightward and leftward. A propagating RF power 162 is distributed. After that, high-frequency power 163 reaching short-circuit portion 153 and high-frequency power 164 reaching short-circuit portion 154 are almost totally reflected at the short-circuit portion, and propagate as high-frequency powers 165 and 166 propagating in opposite directions.

As a result, the high-frequency power supplied from the high-frequency power feeding section 110 and propagating through the surface wave transmission line 150 is substantially totally reflected by the short-circuiting portions 153 and 154 and propagates through the surface wave transmission line 150 again in the opposite direction. It is possible to increase the absorption amount of the high-frequency power propagating through the wave transmission line 150 to the object 102 to be heated, and to improve the heating efficiency of the object 102 to be heated installed inside the surface wave transmission line 150 .

(Embodiment 2)
A second embodiment of the present invention will be described below with reference to the drawings.

In the description of the second embodiment, constituent elements having the same functions as those of the first embodiment are given the same reference numerals, and the description thereof is omitted. Further, the description of the contents having the same functions as those of the first embodiment will be omitted.

FIG. 8 is a schematic diagram showing the configuration of a high-frequency heating device 200 according to Embodiment 2 of the present invention.

The high-frequency heating device 200 shown in the figure further includes a cylindrical metal wall 201, as compared with the high-frequency heating device 100 according to the first embodiment shown in FIG.

The cylindrical metal wall 201 is installed outside the cylindrical surface wave transmission line 101 so as not to come into contact with the surface wave transmission line 101 . The distance between the outer surface of the surface wave transmission line 101 and the metal wall 201 is preferably about 3 mm to 10 mm, but is not limited to this.

The metal wall 201 may be formed by forming a metal plate into a cylindrical shape, or by applying metal plating to a resin plate formed into a cylindrical shape.

As in the first embodiment described above, high-frequency power generated by high-frequency power generating section 103 is fed to surface wave transmission line 101 configured in a cylindrical shape via high-frequency power feeding section 110 . The high-frequency power supplied to the surface-wave transmission line 101 propagates through the surface-wave transmission line 101 as surface-wave power. An object to be heated 102 placed inside 101 is subjected to heat treatment.

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

FIG. 9 shows that when high-frequency power is supplied from a high-frequency power feeder 110 to a cylindrical surface-wave transmission line 101, the high-frequency power propagating through the surface-wave transmission line 101 radiates from the surface of the surface-wave transmission line 101. FIG. 3 is a diagram showing the state of high-frequency power that is applied.

As shown in FIG. 9, the high-frequency power supplied from the high-frequency power feeder 110 is divided into high-frequency powers 221 and 222, which propagate through the surface wave transmission line 101 as surface waves. High-frequency powers 221 and 222 propagating through the surface wave transmission line 101 as surface waves generate a high-frequency power 223 that is radiated inward from the surface of the surface wave transmission line 101 and radiated outward. High frequency power 224 is generated. The high-frequency power 223 radiated inside the cylinder directly contributes to the heating of the object 102 to be heated by being radiated toward the center of the cylinder. On the other hand, the high-frequency power 224 radiated to the outside of the cylinder is reflected by the metal wall 201 of the cylinder and radiated toward the center of the cylinder.

As a result, both the high-frequency power 223 radiated to the inside of the cylinder and the high-frequency power 224 radiated to the outside from the surface of the surface-wave transmission line 101 are placed inside the surface-wave transmission line 101 configured in the cylinder. It contributes to the heating of the object 102 to be heated.

FIG. 10 is a diagram showing an electric field intensity distribution formed in the vicinity of the cylindrical surface wave transmission line 101 when high frequency power is supplied from the high frequency power supply unit 110 to the surface wave transmission line 101. FIG. is.

As shown in FIG. 10, due to the high-frequency power supplied from the high-frequency power feeder 110 and propagating through the surface wave transmission line 101 as surface waves, an inner electric field strength distribution 230 and an outer electric field are generated near the surface wave transmission line 101 . An intensity distribution 231 is formed respectively. Here, the electric field strength distributions 230 and 231 shown in the figure indicate the magnitude of the electric field strength by the depth of color, and the darker the color, the greater the magnitude of the electric field strength.

As shown in FIG. 10, the electric field strength distribution formed near the surface wave transmission line 101 is such that the high frequency power radiated outward from the surface wave transmission line 101 is reflected by the metal wall 201 and radiated inward. By being superimposed on the high-frequency power, the magnitude of the electric field strength of the inner electric field strength distribution 230 increases and the color becomes very dark.

With the configuration as described above, the high-frequency heating apparatus 200 according to the present embodiment generates power in the high-frequency power generator 103 and feeds it to the cylindrical surface wave transmission line 101 through the high-frequency power feeder 110. The contribution rate of the high-frequency power to the heating of the object to be heated 102 placed inside the cylindrical surface wave transmission line 101 can be greatly improved. As a result, even if the object to be heated 102 installed inside the cylindrical surface wave transmission line 101 has a round shape or a shape with a large height dimension, sufficient heat treatment such as scorching of the surface can be stably performed. and can be applied with high efficiency.

(Embodiment 3)
A third embodiment of the present invention will be described below with reference to the drawings.

In the description of the third embodiment, constituent elements having the same functions as those of the first and second embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. Further, the description of the contents having the same effects as those of the above-described first and second embodiments will be omitted.

FIG. 11 is a schematic diagram showing the configuration of a high-frequency heating device 300 according to Embodiment 3 of the present invention.

The high-frequency heating apparatus 300 shown in FIG. A line 301 is provided, a high-frequency power generation unit 303 is provided instead of the high-frequency power generation unit 103, a first high-frequency power supply unit 310a and a second high-frequency power supply unit 310b are provided adjacent to each other instead of the high-frequency power supply unit 110, and heating At the frequency of the high frequency power used for processing, instead of the short circuit 151, a first short circuit 320a and a second short circuit 320b are provided between the adjacent first high frequency power supply 310a and second high frequency power supply 310b. Prepare.

In FIG. 11, the high-frequency heating device 300 has one high-frequency power generating section, two high-frequency power feeding sections, and two short-circuiting sections for one surface wave transmission line. The number of high-frequency power generators, high-frequency power feeders, and short-circuiting parts for one surface wave transmission line is not limited to this.

The high-frequency power generated by the high-frequency power generating section 303 is distributed and supplied to the cylindrical surface wave transmission line 301 via the first high-frequency power feeding section 310a and the second high-frequency power feeding section 310b, respectively. be done. High-frequency power generating section 303, first high-frequency power feeding section 310a, and second high-frequency power feeding section 310b have the same configuration as high-frequency power generating section 103 and high-frequency power feeding section described in the first embodiment. Since the configuration is the same as that of 110, the description is omitted.

Further, the surface wave transmission line 301 is provided with a first short-circuiting portion 320a and a second short-circuiting portion 320b between the first high-frequency power feeding portion 310a and the second high-frequency power feeding portion 310b. . The configurations of the first short-circuit portion 320a and the second short-circuit portion 320b are the same as the configuration of the short-circuit portion 151 described in the first embodiment, and thus the description thereof will be omitted.

FIG. 12 is a development view of the surface wave transmission line 301 shown in FIG. It shows how the high frequency power propagates through the surface wave transmission line 301 .

As shown in the figure, the high-frequency power 330a generated by the high-frequency power generator 303 and fed to the surface wave transmission line 301 via the first high-frequency power feeder 310a is combined with the rightward propagating high-frequency power 331a. The leftward propagating high frequency power 332a is distributed. After that, high-frequency power 333a reaching short-circuited portion 320a and high-frequency power 334a reaching short-circuited portion 320b are almost totally reflected at the respective short-circuited portions, and propagate as high-frequency powers 335a and 336a propagating in opposite directions.

On the other hand, the high frequency power 330b fed to the surface wave transmission line 301 via the second high frequency power feeding section 310b is divided into rightward propagating high frequency power 331b and leftward propagating high frequency power 332b. After that, high-frequency power 333b reaching short-circuited portion 320b and high-frequency power 334b reaching short-circuited portion 320a are almost totally reflected at the respective short-circuited portions, and propagate as high-frequency powers 335b and 336b propagating in opposite directions.

That is, the high-frequency power supplied to the surface wave transmission line 301 from the first high-frequency power feeding section 310a and the second high-frequency power feeding section 310b adjacent to each other is separated by the first short-circuiting section 320a and the second short-circuiting section 320b. be done. As a result, a first heating region 340a in which the object to be heated 102 is heated by high-frequency power 330a fed from the first high-frequency power feeder 310a, and a high-frequency power fed from the second high-frequency power feeder 310b. A second heating region 340b in which the object 102 to be heated is heat-treated is formed by 330b.

As a result, the high-frequency powers supplied from the first high-frequency power feeding section 310a and the second high-frequency power feeding section 310b and propagating through the surface wave transmission line 301 are supplied to the first short-circuiting section 320a and the second short-circuiting section 320a. A first heating region 340a and a second heating region 340b are separated by 320b, and a plurality of feeding sections can be provided in one cylindrical surface wave transmission line, thereby partially controlling the heating state. At the same time, uniformity of heating can be improved.

In the present embodiment, an example is shown in which one high-frequency power generation unit 303 is distributed and high-frequency power is supplied to the first high-frequency power supply unit 310a and the second high-frequency power supply unit 310b. high-frequency power generators may be provided, and high-frequency powers from different high-frequency power generators may be supplied to a plurality of high-frequency power feeders.

Although the high-frequency heating apparatus according to the present invention has been described above based on each embodiment, the present invention is not limited to these embodiments. As long as it does not deviate from the spirit of the present invention, any modification that a person skilled in the art can think of is applied to the embodiment, and a form constructed by combining the components of different embodiments is also included within the scope of the present invention. .

The present invention is a high-frequency heating apparatus that heats an object to be heated by supplying high-frequency power to a surface wave transmission line. Since it is possible to stably perform sufficient heat treatment, it is useful as a cooking appliance such as a microwave heater.

REFERENCE SIGNS LIST 100 high-frequency heating device 101, 150 surface wave transmission line 102 object to be heated 103 high-frequency power generator 110 high-frequency power feeder 111 coaxial cable 112 coaxial cable core 113 antenna 114, 116a, 116b, 116c, 116d bolt 115 fixture 117 coaxial Cable wire fixing protrusions 120, 121, 122, 123, 124 High frequency power 125, 126 High frequency power 130, 131 Electric field strength distribution 151, 153, 154 Short circuit 160, 161, 162, 163, 164, 165, 166 High frequency power 200 high-frequency heating device 201 metal wall 221, 222 high-frequency power 223, 224 high-frequency power 230, 231 electric field intensity distribution 300 high-frequency heating device 301 surface wave transmission line 303 high-frequency power generation section 310a, 310b high-frequency power feeding section 320a, 320b short-circuit section 330a , 330b High-frequency power 331a, 331b High-frequency power 332a, 332b High-frequency power 333a, 333b High-frequency power 334a, 334b High-frequency power 335a, 335b High-frequency power 336a, 336b High-frequency power 340a, 340b Heating region

Claims (5)

at least one surface wave transmission line;
at least one high frequency power generator that generates high frequency power;
at least one high-frequency power feeding unit that feeds high-frequency power to the surface wave transmission line;
The surface wave transmission line is configured in a cylindrical shape, and the high frequency power generated by the high frequency power generating section is directly fed to the surface wave transmission line through the high frequency power feeding section,
A high-frequency heating device , wherein a cylindrical metal wall is installed outside the surface wave transmission line so as not to come into contact with the surface wave transmission line . 2. The high-frequency heating device according to claim 1, wherein said surface wave transmission line has a plate-like periodic structure. 3. The high-frequency heating device according to claim 2, wherein said high-frequency power feeding section feeds high-frequency power to said surface wave transmission line by an electric field coupling type antenna. The high-frequency heating device according to any one of claims 1 to 3, wherein the surface wave transmission line is provided with a short-circuit portion. 5. The surface acoustic wave transmission line according to any one of claims 1 to 4 , comprising a plurality of said high-frequency power feeders, wherein said surface wave transmission line is provided with a short-circuit portion between adjacent said high-frequency power feeders. High frequency heating device.

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