JP3063546B2 - High frequency heating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply (how to insert an electromagnetic wave into a heating chamber) of a high-frequency heating apparatus for heating an object to be heated such as food, and more particularly to an improvement in heating efficiency and a uniform heating distribution. It concerns the intended configuration.

[0002]

2. Description of the Related Art Conventionally, a microwave oven, which is a typical high-frequency heating device, has a configuration as shown in FIGS.

The microwave oven shown in FIG. 16 has a general configuration using a turntable 4. Here, the electromagnetic wave emitted from the magnetron 1 as the electromagnetic wave radiating portion is transmitted through the waveguide 2 and distributed as a standing wave determined by the shape of the heating chamber 3 and the position of the opening 6 in the heating chamber 3. The food 5 generates heat according to the electric field component of the standing wave and the dielectric loss of the food 5. The power P [W / m ³ ] absorbed per unit volume of the food is determined by the applied electric field strength E [V / m], the frequency f [Hz], and the relative permittivity εr and the dielectric loss tangent tan δ of the food ( It is expressed as Equation 1). Since the heating distribution of the food 5 is substantially determined by the standing wave distribution of the electromagnetic waves, in order to suppress the unevenness of the heating distribution, the turntable 4 is rotated to make the heating distribution on the concentric circle uniform.

[0004]

(Equation 1)

[0005] As another uniforming means, a heating chamber 3
Among them, there are a stirrer method in which electromagnetic waves are agitated by a constant rotation of a metal plate, and a rotating waveguide method in which the opening 6 itself of the waveguide 2 is rotated at a constant rate, but a turntable type is the most common. It has been commercialized.

In addition, there is a type in which a plurality of openings 6 are provided for uniformity. FIG. 17 shows a type in which two openings 6 are provided on the wall surface of the heating chamber 3 (Japanese Patent Laid-Open No. 4-31992).
No. 87).

In order to form a plurality of openings 6,
Some have a plurality of magnetrons and a plurality of waveguides (JP-A-61-181093, JP-A-4-345).
788).

In order to form a plurality of openings 6,
Although there is one magnetron, there is a type in which a plurality of waveguides are branched from one waveguide in multiple directions (Japanese Patent Application Laid-Open No. 61-1986).
No. 240029, Japanese Utility Model Laid-Open No. 1-129793).

Also, as shown in FIG. 18, the end faces 39 of the two sub-waveguides 38 are moved at positions facing the plurality of openings 6,
There is also one that aims at uniformity by switching the opening 6 where an apparent electromagnetic wave is likely to be emitted (JP-A-5-74566).

Further, as shown in FIG. 19, by moving a metal 40 in a single waveguide 2 having a plurality of openings 6, the openings 6 which seem to easily emit electromagnetic waves are switched to achieve uniformity. (JP-A-3-11588 and JP-A-5-121160).

Also, only in the case of thawing cooking, there is a product in which the turntable 4 is raised to a certain height to achieve a certain degree of uniformity without a rack dedicated to thawing.

Further, there is one in which a user changes the setting of the height of the turntable 4 in accordance with the purpose of cooking (Japanese Patent Laid-Open No.
-144224).

The weight and shape of the food 5 are determined by various sensors.
Devices that perform feedback control by detecting temperature, dielectric constant, temperature, humidity, electric field, and the like in a heating chamber have been put to practical use.

[0014]

However, according to the above-mentioned conventional configuration, when the waveguide 2 and the heating chamber 3 are connected to each other and electromagnetic waves are introduced into the heating chamber 3, the heating distribution is uniform for each material and shape of the food 5. However, there is a problem that it is not possible to heat all the foods 5 uniformly with one opening 6.

In particular, an opening 6 is provided near the center of the bottom of the heating chamber 3.
When the food 5 is provided, the bottom surface of the food 5 is heated, and if the liquid food 5 has convection, the food 5 can be uniformly heated. However, the solid food 5 without convection has a problem that the temperature rises only at the bottom.
On the other hand, when the opening 6 is provided at the end of the bottom of the heating chamber 3,
By optimizing the position of the opening and the height at which the food 5 is placed for each food 5, there is a possibility that the solid food 5 without convection can be heated uniformly, but this has not been realized until now.

At this time, if the turntable 4 is used, the heating distribution on the concentric circle can be made uniform. However, no matter how much the turntable 4 is rotated, the distribution in the radial direction and the distribution in the vertical direction viewed from the center of rotation are not changed. Not improved.

In the case of a stirrer or a rotating waveguide, such as a stirrer or a rotating waveguide, the electric field distribution is changed in such a manner that the opening 6 is switched in accordance with the rotation. This has the effect of avoiding concentration on the menu that you want to avoid. However, since the stirring is performed at a constant rotation regardless of the food 5, heating is performed by repeating the same electric field distribution every rotation of any food 5. Therefore, complete homogenization cannot be achieved, and oscillation frequency fluctuation and harmonic noise Easy to occur.

Even when a plurality of openings 6 are provided, simply opening the openings 6 at the same time creates a certain electric field, making it difficult to equalize the heating distribution of all the foods 5. 17 microwave ovens and FIG. 18
There is no big difference in the heating distribution of the microwave oven. After all, unless the appropriate opening 6 is switched for each food item 5, the user cannot achieve a satisfactory finished state.

In the case of a device having a plurality of magnetrons and a plurality of waveguides, the opening 6 from which an electromagnetic wave is emitted can be switched by controlling the operation of the magnetron, which is effective for uniform heating distribution. There are problems such as high price depending on the number, heavy weight and difficulty in carrying.

Although there is a single magnetron and a plurality of waveguides branched from one waveguide in multiple directions, the opening 6 from which an electromagnetic wave is easily emitted cannot be completely switched. There is a problem that a certain amount of electromagnetic waves is emitted from the opening where the electromagnetic waves are not desired to be emitted. In addition, since a large amount of sheet metal material required for the waveguide is required, the price becomes high,
There are problems such as difficulty in making.

Therefore, as shown in FIG. 19, there is a method in which the end face 26 of the sub-waveguide 7 is moved at a position opposed to the plurality of openings 6 to switch the openings 6 in which electromagnetic waves are apparently emitted.
This is effective for uniform heating distribution. However, considering an actual configuration, a space occupied by the plurality of sub-waveguides 7 and a space for a plurality of shield configurations for preventing leakage of electromagnetic waves when the end face 26 of the sub-waveguide 7 is moved are required. Therefore, there is a problem that the size of the entire microwave oven becomes large or the effective volume inside the heating chamber 3 with respect to the whole size becomes small. For the user, if the overall size is large, it is difficult to place it, and if the effective volume is small, the user is dissatisfied that only a small food 5 can be contained. Similarly, the microwave oven becomes heavy, causing a problem that it is difficult to carry. Operating the sub-waveguide 7 including the shield configuration at a plurality of locations may consume considerable power.

Further, even if a metal is moved in a single waveguide having a plurality of openings 6, the openings 6 from which electromagnetic waves are likely to be emitted cannot be completely switched, and the openings from which electromagnetic waves are not desired to be emitted cannot be changed. However, there was a problem that some electromagnetic waves were emitted. Further, in the configuration shown in FIG. 19, it is not clear which one of the openings 6 emits the electromagnetic wave when it is moved.

When the height of the turntable 4 is changed, the heating distribution changes. However, if the turntable 4 is raised to a certain height by a single process such as thawing, it will not be possible to respond to each food in the end. Uniformity cannot be achieved.

Further, it is very inconvenient for the user to change the setting of the height of the turntable 4 in accordance with the purpose of cooking, and if the setting of the height is incorrect, the heating distribution becomes severe. Further, among sensors that detect the state of the food 5 and perform feedback control by using a sensor, when a sensor that detects the state of initial heating or a state change from the initial heating is used, a malfunction (erroneous detection) due to electromagnetic waves may be caused. There was a case where the start-up (from the time when the electromagnetic wave began to stabilize) to a certain time was delayed. That is, the electromagnetic wave is not emitted (no heating) until the sensor has finished detecting the initial heating state, and there is a problem that the total heating time becomes longer and the waiting time for the user increases.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to realize a high-frequency heating device for making a heating distribution of an object to be heated uniform.

[0026]

Means for Solving the Problems A high-frequency heating apparatus according to the present invention has the following configuration to solve the above-mentioned problems.

That is, a heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a first waveguide for transmitting electromagnetic waves radiated from the electromagnetic wave radiating section, and a plurality of heating chambers in the heating chamber. A plurality of waveguides branched from the first waveguide and partially adjacent to each other to guide electromagnetic waves through the opening, and a control unit that controls operations such as emission of electromagnetic waves from the electromagnetic wave emission unit. Configuration.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating portion that radiates an electromagnetic wave, a first waveguide that transmits the electromagnetic wave radiated from the electromagnetic wave radiating portion, and the first waveguide for guiding the electromagnetic wave through the plurality of openings into the heating chamber. A configuration is provided that includes a plurality of waveguides branched at a node of an electric field in the tube, and a control unit that controls operations such as emission of electromagnetic waves from the electromagnetic wave emission unit.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating portion that radiates an electromagnetic wave, a first waveguide that transmits the electromagnetic wave radiated from the electromagnetic wave radiating portion, and the first waveguide for guiding the electromagnetic wave through the plurality of openings into the heating chamber. A plurality of waveguides branching from the tube and having a cross-sectional area in the traveling direction of the electromagnetic wave smaller than the cross-sectional area of the first waveguide, and a control unit that controls operations such as emission of electromagnetic waves from the electromagnetic wave emission unit. .

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating portion that radiates an electromagnetic wave, a first waveguide that transmits the electromagnetic wave radiated from the electromagnetic wave radiating portion, and the first waveguide for guiding the electromagnetic wave through the plurality of openings into the heating chamber. A plurality of waveguides that branch from the tube and have a length in the traveling direction of the electromagnetic wave from the branched position to the terminal end that is substantially an integral multiple of 0 or more of の of the in-tube wavelength λg; And a control unit for controlling operations such as emission of electromagnetic waves.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating portion that radiates an electromagnetic wave, a first waveguide that transmits the electromagnetic wave radiated from the electromagnetic wave radiating portion, and the first waveguide for guiding the electromagnetic wave through the plurality of openings into the heating chamber. The structure includes a plurality of waveguides branching from the tube at a width of approximately 以下 or less of the guide wavelength λg, and a control unit for controlling operations such as emission of electromagnetic waves from the electromagnetic wave emission unit.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section that radiates an electromagnetic wave, a waveguide that guides an electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings, and a section of the heating chamber or the heating chamber and the waveguide. A shielding part made of metal or conductive for operating to shield or open at least a part of the plurality of openings between or in the waveguide, and the shielding part being in contact with the shielding part. A projection is provided on either the heating chamber or the waveguide or at least one of the metal or conductive member fixed to the waveguide, and controls the emission of the electromagnetic wave from the electromagnetic wave emission unit and the operation of the shielding unit. And a controller that performs the control.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section that radiates an electromagnetic wave, a waveguide that guides an electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings, and a section of the heating chamber or the heating chamber and the waveguide. A shielding part made of metal or conductive for operating to shield or open at least a part of the plurality of openings between or in the waveguide, and the shielding part and the shielding part A sealing portion formed in the heating chamber or the waveguide or at least one of the members fixed to at least one of the plurality of openings to suppress electromagnetic waves leaking from between the plurality of openings to be shielded; and the electromagnetic wave radiation. And a control unit for controlling the emission of electromagnetic waves from the unit and the operation of the shielding unit.

Also, a heating chamber composed of a plurality of wall surfaces for taking in and out the object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, and an electromagnetic wave radiated from the electromagnetic wave radiating section are transmitted through a plurality of openings. A waveguide for guiding into the heating chamber, and shielding or opening at least a plurality of openings on the same wall surface of the heating chamber in the heating chamber or between the heating chamber and the waveguide or in the waveguide. A shielding unit made of metal or having conductivity so as to operate, and a control unit that controls the emission of electromagnetic waves from the electromagnetic wave emitting unit and the operation of the shielding unit.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section that radiates an electromagnetic wave, a waveguide that guides an electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings, and a section of the heating chamber or the heating chamber and the waveguide. A shield made of metal or conductive to operate to shield or open the plurality of openings between or within the waveguide and the heating chamber or to drive the shield; One drive unit configured on either the waveguide or at least one of the members fixed to at least one of the waveguides and control for controlling the drive unit that emits electromagnetic waves from the electromagnetic wave emission unit or operates the shielding unit. And a part.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section that radiates an electromagnetic wave, a waveguide that guides an electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings, and a section of the heating chamber or the heating chamber and the waveguide. A shielding portion made of metal or conductive for operating to shield or open at least a part of the plurality of openings between or in the waveguide, and emission of electromagnetic waves from the electromagnetic wave emission portion And a control unit for controlling the operation of the shielding unit, wherein the control unit operates the shielding unit when the emission of the electromagnetic wave from the electromagnetic wave emitting unit is stopped.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section that radiates an electromagnetic wave, a waveguide that guides an electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings, and a section of the heating chamber or the heating chamber and the waveguide. A shielding portion made of metal or conductive for operating to shield or open at least a part of the plurality of openings between or in the waveguide, and emission of electromagnetic waves from the electromagnetic wave emission portion And a control unit for controlling the operation of the shielding unit, wherein the control unit becomes a position suitable for heating a light object to be heated or heating for a short time at the start of heating or at the end of heating. The control is performed as follows.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating portion that radiates an electromagnetic wave, a waveguide that guides the electromagnetic wave radiated from the electromagnetic wave radiating portion into the heating chamber through an opening, and changes the position of the object to be heated or heats the object to be heated and A drive unit that changes the distance between a metal or a conductive member below the bottom of the object, and a control unit that controls the emission of electromagnetic waves from the electromagnetic wave emission unit and the operation of the drive unit, wherein the control unit is At the start of heating or at the end of heating, the drive unit is controlled so that the position of the object to be heated is a light object to be heated or a position suitable for short-time heating.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section for radiating electromagnetic waves, a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through an opening, and physical quantities (weight, shape, temperature, dielectric constant, etc.) of the object to be heated And a detection unit for detecting a state (temperature, humidity, electric field, and the like) and a change in the heating chamber, and a control unit that receives an output of the detection unit and controls emission of electromagnetic waves from the electromagnetic wave emission unit. The control unit does not receive or ignores the output of the detection unit for a while after the start of heating by the emission of the electromagnetic wave from the electromagnetic wave emission unit.

A heating chamber for taking in and out the object to be heated;
An electromagnetic wave radiating section that radiates an electromagnetic wave, a waveguide that guides an electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings, and a section of the heating chamber or the heating chamber and the waveguide. A shielding part made of metal or conductive for operating to shield or open the plurality of openings between or within the waveguide, and a physical quantity (weight, shape, temperature, A detecting unit for detecting the state of the heating chamber (temperature, humidity, electric field, and the like) and its change, and receiving the output of the detecting unit to emit electromagnetic waves from the electromagnetic wave emitting unit and the shielding unit. A control unit for controlling an operation, wherein the control unit operates the shielding unit a plurality of times during a period from the start of heating to the end of heating depending on an output of the detection unit.

Further, a heating chamber for taking in and out the object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section through the opening into the heating chamber, A driving unit that changes the position of the object to be heated or the distance between the object to be heated and a metal or a conductive member below the bottom of the object to be heated, and a physical quantity (weight, shape, temperature, dielectric constant) of the object to be heated Etc.) and a state (temperature, humidity, electric field, etc.) in the heating chamber and a change in the state, and receiving an output of the detection section, radiating electromagnetic waves from the electromagnetic wave radiating section and operating the driving section. A control unit for controlling the control unit, wherein the control unit operates the drive unit a plurality of times from the start of heating to the end of heating depending on the output of the detection unit.

[0042]

The present invention has the following effects by the above-mentioned structure.

That is, since the plurality of waveguides branched from the first waveguide are adjacent to each other, the plurality of waveguides are formed in a small space with a small number of members.

Further, since the plurality of waveguides branch at the node of the electric field of the first waveguide, the electromagnetic waves in the first waveguide are efficiently transmitted to the plurality of waveguides.

Further, since the cross-sectional area of the plurality of waveguides branched from the first waveguide is smaller than the cross-sectional area of the first waveguide in the traveling direction of the electromagnetic wave, the space after the branch is large. No.

In addition, the plurality of waveguides branched from the first waveguide are such that the length in the traveling direction of the electromagnetic wave from the branch position to the end portion is approximately an integer of 0 or more, which is 内 of the guide wavelength λg. The wavelength λg in each of the plurality of waveguides.
Resonates at

Further, since the width of the branch from the first waveguide by the plurality of waveguides is set to １ ／ or less of the guide wavelength λg,
The electromagnetic wave in the first waveguide is transmitted to the plurality of waveguides while remaining in a resonance state.

Also, the shielding portion may be shielded or opened while being in contact with a protrusion on a metal or conductive member fixed to the heating chamber and / or the waveguide. Since it operates, it is completely shielded from electromagnetic waves.

Further, since the seal portion is formed in the heating chamber and / or the waveguide or a member fixed to at least one of them, electromagnetic waves leaking from between the shielding portion and the plurality of openings are suppressed. , The ability of shielding is increased.

Further, since a plurality of openings on the same wall are shielded or opened by one shield, the structure of the shield is simplified and the number of components is reduced.

In addition, since a single drive unit operates a shield unit that shields and opens a plurality of openings, the structure of the drive unit is simplified and the number of components is reduced.

Further, since the shielding portion is operated when the emission of the electromagnetic wave is stopped, the electric field is not disturbed by the operation of the shielding portion.

At the start of heating or at the end of heating, the position of the shielding portion is set at a position suitable for heating a light object to be heated or heating for a short time. The number of times the shield is moved anew is reduced.

When the heating is started or ended, the driving unit is controlled so that the position of the object to be heated is a light object to be heated or a position suitable for short-time heating. In the case of heating for a short time, the number of times that the position of the object to be heated is newly moved is reduced.

In addition, since the output of the detection unit is not received or ignored for a while after the start of heating, regardless of the capability of the detection unit, heating is performed quickly and efficiently immediately after the start of heating.

Also, depending on the output of the detection unit, the shielding unit is operated a plurality of times during the period from the start of heating to the end of heating.
Thereby, the heating distribution of the object to be heated changes.

Also, depending on the output of the detecting section, the movable section is controlled so as to change the position of the object to be heated a plurality of times between the start of heating and the end of heating, so that the heating distribution of the object to be heated changes.

[0058]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a high-frequency heating device according to an embodiment of the present invention. An electromagnetic wave emitted from a magnetron 1 which is a typical electromagnetic wave radiating part heats a food 5 on a turntable 4 in a heating chamber 3 via a waveguide 2. The electromagnetic wave emitted from the magnetron 1 is transmitted to the first waveguide 2
A branches into waveguides 2B and 2C at a branch point 7 from the heating chamber 3
Electromagnetic waves are transmitted into the heating chamber 3 through the openings 6A and 6B on the bottom surface. At this time, adjacent portions of the wall surfaces of the waveguides 2B and 2C are formed of a common metal plate. Further, the branch point 7 is formed at a place (node) where the electric field is weak in the first waveguide 2A. The first waveguide 2A is a magnetron 1
The wall 9 facing the antenna 8 of the
Although the distance between the antenna and the wall surface 9 is increased, the distance may be reduced because the waveguides 2B and 2C do not have a protrusion like the antenna 8 does. Therefore, compared to the first waveguide 2A, the waveguide 2B,
Since the cross-sectional area of 2C may be narrowed, a space-saving configuration can be provided for a plurality of waveguides overlapping. In the present embodiment, the first waveguide 2A is considered based on the waveguides 2B and 2C.
The cross-sectional area on the side is widened by the wall surface 9. Waveguide 2
The length of B and 2C is the guide wavelength λ from the branch point 7 to the end.
The fact that the value is approximately an integral multiple of 1/2 of g and the width of the branch point 7 is 1/4 or less of the guide wavelength λg will be described in detail with reference to FIG.

The metal shield 10 is provided with a drive 11
Thus, by operating between the openings 6A and 6B while contacting the heating chamber 3 and the protrusions 12 on the waveguides 2B and 2C, the openings 6A and 6B that easily transmit electromagnetic waves are switched. The seal 13 prevents electromagnetic waves from leaking outside the heating chamber 3 and the waveguide 2 irrespective of the position of the shield 12.

The controller 14 includes a temperature detector 15 for detecting the temperature of the food 5, a weight detector 16 connected to the turntable 4 for detecting the weight of the food 5, and a shape detector for detecting the shape of the food 5. Based on detection signals from 17A and 17B (for example, those which emit light from 17A and grasp the shape by the detected amount at 17B), radiation of electromagnetic waves from magnetron 1 and operation of fan 18 for cooling magnetron 1 are performed. ,
The operation of the drive unit 11 for the shielding unit 10 and the turntable 4
The operation of the rotation drive unit 19 for rotating the motor and the operation of the height drive unit 20 for changing the height of the turntable 4 are controlled. In particular, control is performed to move the shielding unit 10 when no electromagnetic wave is emitted from the magnetron 1. When the heating is completed, the position of the shielding unit 10 and the turntable 4 are removed.
Is controlled so that the heating distribution and the heating efficiency of the lightweight food 5 are maximized.
In addition, in heating for any purpose, when the user puts the food 5 and starts heating, an electromagnetic wave is immediately generated, and the behavior of the electromagnetic wave immediately after the start of heating becomes unstable (so-called rising). The detection unit (for example, the weight detection unit 16) that has a possibility of erroneous detection is controlled so as not to receive or ignore the output of the detection unit until it becomes stable. Further, depending on the food 5 (especially a large amount of food), the position of the shielding unit 10 and the height of the turntable 4 are operated a plurality of times during heating to optimize heating distribution and heating efficiency. .

Here, when the position of the shielding unit 10 is changed by the driving unit 11, of the plurality of openings 6 A and 6 B, the opening from which electromagnetic waves are easily emitted and the opening that is difficult to emit are switched, and the electric field distribution in the heating chamber 3 can be switched. . In particular, since the position of the shielding unit 10 can be freely set in accordance with signals from various detection units, an appropriate electric field distribution state according to the purpose of heating can be achieved. Although not shown in FIG. 1, in order to accurately determine the position of the shielding unit 10, it is easily conceivable to determine a reference point somewhere and manage the position of the shielding unit 10 based on the moving distance from the reference point. .

When the height h of the turntable 4 is changed by the height adjusting section 20, the height of the food 5 changes.
Even in the case of the same electric field distribution, the heating distribution of the food 5 can be changed. Therefore, similarly, if the height h of the turntable 4 is adjusted to the optimum height h in accordance with the difference in the electric field distribution depending on the signal from the various detection units and the position of the shielding unit 10, the appropriate heating according to the purpose of heating can be achieved. Can be distributed. Although not shown in FIG. 1, similarly to the shielding unit 10, in order to accurately determine the height h of the turntable 4, the height may be managed based on a reference point and a moving distance.

The turntable 4 is normally rotated to make the food 5 uniform in the concentric direction as viewed from the center of rotation, but the rotation and stop (or variable speed) can be freely set by the rotation drive unit 19. . For example, when it is determined by the temperature detecting unit 15 that the temperature is uneven during the heating, the heating distribution is changed by the shielding unit 10 and the height driving unit 20 to search for a state in which the temperature unevenness can be eliminated.
When that happens, stop or slow down,
It is also possible to eliminate irregularities quickly.

The configuration of the temperature detecting section 15 itself will be further described. As a general temperature detection unit 15 that detects temperature without contact, there is an infrared sensor that converts the amount of infrared radiation emitted from the food 5 into an electric signal. As the infrared sensor, there are a thermopile type having a hot junction and a cold junction therein, a pyroelectric type having a chopper, and the like, and either of them may be employed in the present invention.

Further, although not shown in FIG. 1, the openings 6A and 6B are generally covered with an opening cover made of a low-loss material that does not easily absorb electromagnetic waves from the heating chamber 3 side.

FIG. 2 is a sectional view of a main part of a high-frequency heating apparatus according to another embodiment of the present invention. The electromagnetic wave supplied from the antenna 8 of the magnetron 1 to the waveguide 2A maximizes the electric field at the antenna 8 (the antinode 21 of the electric field), and thereafter becomes weaker every quarter of the guide wavelength λg (the node 22 of the electric field). ,
It is transmitted to the left and right in FIG. 2 while strengthening or repeating the antinode 21 of the electric field. At this time, since the left and right end faces of the waveguide are designed so as to serve as nodes of the electric field, the electric field in the waveguides 2A and 2C neatly repeats the antinode 21 of the electric field and the node 22 of the electric field. Here, since the guide wavelength λg is determined by the distance C in the depth direction in FIG. 2, there is a degree of freedom in the distance D1 in the height direction, but if the distance between the antenna 8 and the opposing wall surface 9 is too short (if it becomes 5 mm or less). ) Since an abnormal state such as discharge may occur, a certain distance must be maintained. The branch point 7 is formed in the electric field node 22 in the middle of the waveguides 2A and 2C. This is a branch point 7 from the viewpoint of electromagnetic waves.
Is considered to be an opening, so that an electric field 23 is applied so as to sandwich the branch point 7, whereby the waveguides 2A, 2C
This is to prevent the electric field inside from being disturbed. Then, the electromagnetic wave transmitted from the branch point 7 into the waveguide 2B is similarly subjected to an electric field 23 so as to sandwich the branch point 7, and since the distance C in the depth direction of FIG. It is transmitted left and right. Here, the length from the branch point 7 to the right end face 24 is 1/2 times λg, and the length from the branch point 7 to the left end face 25 is ／ times λg.
The electric field inside is regularly repeating the antinode 21 of the electric field and the node 22 of the electric field. Further, since there is no protruding portion such as the antenna 8 in the waveguide 2B, the distance D2 in the height direction can be reduced within a range where discharge does not occur between the wall surfaces. Here, the sectional area is reduced to half or less as D2 <D1 / 2. Here, if the width A of the branch point 7 is too large, the orderly state of the electromagnetic waves of the waveguides 2A and 2C is disturbed. If the width A is too small, the energy transmitted to the waveguide 2B decreases. It is slightly smaller.
Similarly, the opening 6 for transmitting an electromagnetic wave into the heating chamber 3 is slightly smaller than １ ／ of λg. Further, the waveguides 2A and 2C and the waveguide 2B are adjacent to each other, and the wall surface 26 is shared.

FIG. 3 is a perspective view showing a main part of a high-frequency heating apparatus according to another embodiment of the present invention. (Each component is actually connected, but is shown in a different state for easy viewing.) The opening 6 and the opening 6 are respectively provided in the heating chamber 3 and the waveguide 2.
Are formed in the metal so as to surround them, and projecting portions 12A and 12B are formed. (However, the waveguide 2 has a wall constituting portion 27 and a projecting portion 28.) The projecting portion 12A and the projecting portion 12B protrude so as to face each other, and are made of metal so that they can be driven while contacting both. Is configured. The electromagnetic wave in the waveguide 2 is transmitted into the heating chamber 3 only when the shield 10 is not on the opening 6. Further, the waveguide 2 and the heating chamber 3 are connected to each other in order to suppress the leakage of the electromagnetic waves to the outside. In particular, the electromagnetic waves in the E direction are shielded by the seal portion 13. The seal portion 13 is made of metal having a groove having a depth of F,
By setting ≒ λg / 4, the upper surface 29 of the seal portion 13 in the figure can be obtained.
Electromagnetic waves are not transmitted to the E side. In general,
The impedance (indicator of difficulty in transmitting to the E side) viewed from the electromagnetic wave traveling in the E direction changes with F. The value of the impedance is represented by Zin = j · Z0 · tan (2π · F / λg). When F = λg / 4, | Zin | = Z0 · tan (π
/ 2) = ∞ (impedance is infinite), and position 2
Electromagnetic waves are not transmitted from E to E side. The concept of the impedance is the same as the concept of a microstrip line often used in a radio wave sealing device of a microwave oven, and various other embodiments which are compact can be considered (Japanese Patent Laid-Open No. 6-13207).

FIG. 4 and FIG. 5 are main part configuration diagrams of a high-frequency heating apparatus according to another embodiment of the present invention.
And a state in which a plurality of openings 6A and 6B are switched by one shielding unit 11.

FIG. 4 shows a case where the opening 6A is opened and the opening 6B is shielded. FIG.
FIG. 4B is a configuration diagram of the portion below the shielding portion 10 of FIG. 4A from above. The rotation of the gear-shaped driving unit 11 causes the shielding unit 10 to move the projection 1 between the heating chamber 3 and the waveguides 2B and 2C.
The opening 6 that operates while contacting the electromagnetic wave 2 and transmits electromagnetic waves.
Switch between A and 6B. In this case, the opening 6A is opened because it overlaps with the cut 30 of the shielding portion 10, and the opening 6B is opened.
Are shielded by the shielding unit 10.

FIG. 5 shows a case where the opening 6A is shielded and the opening 6B is open. FIG.
FIG. 5B is a configuration diagram of the portion below the shielding section 10 of FIG. 5A from above. In this case, the opening 6A is shielded by the shield 10, and the opening 6B is open because it is shifted from the shield 10.

FIG. 6 is a characteristic diagram of a high-frequency heating device according to another embodiment of the present invention. This is called a Rieke diagram representing the operating point of the magnetron 1 and shows the ease of entry of electromagnetic waves into the heating chamber 3. The area where the electromagnetic wave is most likely to enter is the area 31, and the electromagnetic wave stops entering as it goes outward. Obviously, when the electromagnetic wave stops entering, the heating efficiency decreases, and the loss that changes to heat generation in the electromagnetic wave radiation part increases. As an example, a case will be described in which the openings 6A to 6B are switched while emitting the electromagnetic waves. It is assumed that the operating point is at 32 when the opening 6A is opened and the opening 6B is shielded. However, when the opening 6A is gradually closed and the opening 6B starts to be opened, the operating point starts moving in the direction of the arrow, and when the opening is just half opened, the operating point becomes 33, and then the opening is completely cut off. It returns to the operating point 32 when it has changed. In other words, this indicates that a state in which the electromagnetic wave is difficult to enter occurs during the operation of the shielding unit 10. During this operation, not only the loss of the electromagnetic wave radiating section as described above increases, but also various problems such as fluctuation of the oscillation frequency and generation of harmonic noise may occur in some cases. Therefore, in the present invention,
When the shielding unit 10 is operated, the problem is solved by controlling not to emit an electromagnetic wave from the electromagnetic wave emitting unit.

FIGS. 7 to 10 are a characteristic diagram and a main part configuration diagram of a high-frequency heating device according to another embodiment of the present invention, and show the relationship between the position of the opening 6 and the height h of the food 5. It shows how to make the heating distribution uniform.

FIG. 7 shows the heating when the temperature of the food 5 is measured by changing the height h when the electromagnetic wave is transmitted into the heating chamber 3 by only one of the openings 6A and 6B. It is a characteristic view which shows distribution unevenness. The abscissa indicates the number of the opening that is open, and the ordinate indicates the difference between the highest temperature and the lowest temperature when the temperature is measured at a plurality of locations. The smaller the value, the less uneven distribution. h1 is height h = 10 mm, h2 is height h
= 30 mm. This is a characteristic diagram in the case where 100 g of frozen beef sliced meat is thawed and cooked as food 5,
The best conditions are an opening 6A and a height of 30 mm. However, when similarly measured with a generally sold microwave oven, the unevenness is about 32 to 60 ° C., which is somewhat improved by this embodiment. 100g of beef sliced meat in this case is
The food 5 has a typical shape with a small height (thickness t) and a small weight.

FIG. 8 is a cross-sectional view of a main part having a height of 30 mm, in which only the opening 6A under the optimum conditions shown in FIG. 7 is formed.

FIG. 9 is a characteristic diagram when thawed and cooked using 300 g of frozen beef sliced meat as the food 5. The best conditions are an opening 6B and a height of 10 mm. However, when the same measurement was carried out using a generally sold microwave oven, the unevenness was about 32 to 75 ° C., which was also somewhat improved by this embodiment. Beef sliced meat 30 in this case
0 g is a standard shape having a height (thickness t) and a general weight among the foods 5.

FIG. 10 is a cross-sectional view of a main portion having a height of 10 mm and including only the opening 6B under the optimum conditions of FIG.

As can be seen from FIGS. 7 to 10, if the foods 5 of the same material have different weights, the height h of the openings 6 and the heights of the foods 5 must be switched in order to give an optimum distribution. Here, in the present invention, after each heating,
The opening is set to 6A and the height h is set to 30 mm, and the standby is set for the light-weight food 5. Because the heating time is shorter for lighter weights, the distribution cannot be improved until the end of heating even if switching midway, or heating is started in a state of poor heating efficiency even though the heating time is short. This is to prevent the delay from being extended. On the other hand, in the case of a large amount of foods 5, since the time until the end of heating is long, there is ample room for switching even in the middle. When the user actually heats the food 5, the radiation of the electromagnetic wave from the magnetron 1 and the rotation of the turntable 4 are started. Then, during the heating, the temperature detecting unit 15, the weight detecting unit 16, and the shape detecting units 17A, 17
Various states such as the quantity, shape, and temperature of the food 5 are determined based on the signal from B. Since it is configured to heat the light-weight food 5 in the initial state, if it is determined that the food is large, the opening 6
And the height h are controlled to have an appropriate configuration, and thereafter heating is performed for a predetermined time set by the user, or the heating is terminated when the temperature reaches an appropriate level by various detection units.

Further, in order to realize uniform heating without any irregularities in the heating distribution of any food 5, it is necessary to optimize the food 5 in advance in accordance with conditions such as the material, shape, placed position and temperature of the food 5. There is a method in which information on the position of the opening 6 and the height h is stored in advance in a microcomputer in the control unit 14 as a database. By this method, the control unit 14
Are the temperature detector 15, the weight detector 16, the shape detector 17
Compare the output from A, 17B etc. with the database,
Control for optimal heating is possible.

Here, as one embodiment according to the present invention, in the case of a large amount of foods 5, a state change (particularly, a temperature change as heating progresses) is fed back, and an appropriate opening is formed so as to eliminate uneven distribution at that time. Since the six positions and the height h are changed a plurality of times, a heating distribution with better characteristics than in FIG. 9 can be obtained.

FIG. 11 is a characteristic diagram showing another embodiment of the present invention, where the horizontal axis represents time t and the vertical axis represents high-frequency output P. Generally, for a while after the electromagnetic wave starts to be emitted from the electromagnetic wave radiating portion, t
Since S is unstable, it tends to generate noise such as harmonics. Therefore, conventionally, when a detection unit that is weak against noise is used to detect the state of the food 5 at the initial stage of heating, as shown in FIG. 11A, detection is performed without emitting an electromagnetic wave during the period of tM, and detection is completed. In some cases, an electromagnetic wave is emitted later and reaches a stable heating state tF after ts. This is tM
During this period, the heating efficiency is extremely low because heating is not performed. Therefore, in the present invention, as shown in FIG. 11B, an electromagnetic wave is immediately emitted to start heating, and ts
, A stable heating state tF is reached, and the state of the food 5 in the early stage of heating is detected after tS + Δt (soon to be stable). Therefore, the state of the food 5 is accurately detected without lowering the heating efficiency.

FIGS. 12 to 15 are diagrams showing the results of simulating the electric field inside the high-frequency heating device.

FIG. 12 is a perspective view of a high-frequency heating device according to one embodiment of the present invention. An electromagnetic wave is excited from a feed point 34 indicating the antenna 8 of the magnetron 1.

FIGS. 13 and 14 are simulated electric field distributions (when there is no food) of the high-frequency heating device of FIG. 12 and are perspective views cut along the line GG ′. Shown by lines. (It can be considered that the more complicated the annual ring-shaped pattern, the stronger the electric field (antinode). This indicates a difference in electric field distribution depending on the position of the opening.

FIG. 13 shows a case in which only the first opening 6A is open. In the heating chamber 3, there are four antinodes in the X direction, three antinodes in the Y direction, and three antinodes in the Z direction. The antinode of the electric field is 1
Has occurred.

FIG. 14 shows a case in which only the second opening 6B is opened. In the heating chamber 3, there are five antinodes in the X direction, one antinode in the Y direction, and one antinode in the Z direction. The antinode of the electric field is 1
Has occurred.

Here, the reason why the electric field distribution as shown in FIGS. 13 and 14 occurs will be described. First, the propagation of an electromagnetic wave in the waveguide 2 will be described.

FIG. 15 is a sectional view of a main part of a high-frequency heating apparatus according to one embodiment, in which only the magnetron 1, the waveguide 2, the heating chamber 3, and the opening 6 are simply shown. The distance L between the feeding point 34 of the magnetron 1 and the center 35 of the opening 6 is
If the wavelength (guide wavelength) of the electromagnetic wave transmitted to the left in the waveguide 2 is represented as λg, the distance is an odd multiple of λg / 4. As described with reference to FIG. 2, when the electromagnetic wave is transmitted through the waveguide 2, it repeats the strength based on the guide wavelength λg determined by the shape of the waveguide 2 while repeating the strength in FIG.
To the left, and the electric field always weakens at the position of an odd multiple of λg / 4 (the phase of the magnetic field and the electric field match in transmission in the waveguide, and the magnetic field also weakens). Here, it is assumed that L = λg × 9/4. The solid arrow indicates the direction of the strong electric field, and the direction of the electric field (and the magnetic field) is reversed every λg / 2.
The direction of the arrow is reversed every g / 2 away, but each repeats the inversion at a frequency of 2.45 GHz. In FIG. 15, since the electric field (and the magnetic field) is connected to the opening 6 of the heating chamber 3 at a weak place, the electromagnetic wave easily enters the heating chamber 3 efficiently without disturbing the electric field in the waveguide 2.

Here, the guide wavelength λg propagating in the waveguide 2
When the definition of FIG. 15 is described according to FIG. 15, the depth of the waveguide 2 is C, the thickness is D, the number of peaks of the radio wave in the depth direction is m, and the number of peaks of the electromagnetic wave in the thickness direction is n. If the wavelength of the electromagnetic wave in a vacuum is λ ≒ 122 mm, then (Equation 2) is obtained.
Generally, m = 1 and n = 0 are often used, and in this case, (Equation 3) is obtained. Specific values C = 80 mm, D = 40 mm
Then, λg is about 188 mm. (However, all dimensions do not include the board thickness.)

[0090]

(Equation 2)

[0091]

(Equation 3)

Next, the resonance of the electromagnetic wave in the heating chamber 3 at this time will be described. In the case of FIG. 15, the electromagnetic waves in the heating chamber 3 tend to cause a resonance state, but strong electric fields 36 and 37 (solid arrows) that oppose the opening 6 are generated, and the opening in the heating chamber 3 is opened. 6 stabilizes in a resonance state in which the electric field becomes weak (node). At this time, the most efficient heating room 3
Electromagnetic waves will enter inside. (However, in the resonance state,
Unlike the transmission state as in the waveguide 2, the phases of the electric field and the magnetic field are shifted by 90 °. Although the resonance state is determined by the shape of the heating chamber and the position of the opening, at this time, in the case of FIG. 13 showing the electric field distribution in the heating chamber 3, there are four in the X direction of the heating chamber, three in the Y direction, and three in the Z direction. One strong electric field is generated. This is the antinode of the electric field caused by the electromagnetic wave being distributed as a standing wave in the heating chamber due to the resonance, and the number of antinodes is called a mode. Normally, when the shape of the heating chamber 3 is expressed in three dimensions and the dimensions in each direction are x, y, and z, if the antinodes of the electric field are only m, n, and p in each direction, the mode is (mnp). There is. In the present embodiment, the center position of the first opening 6A is approximately aligned with the center position of the depth x and the width y of the bottom surface of the heating chamber 3 and at the same time, a strong electric field is generated so as to sandwich the opening 6. So that it becomes a node at the opening 6A
With this configuration, an even mode (m; even number) is likely to stand in the depth x direction, and an odd mode (n: odd number) is likely to stand in the width y direction, and it is difficult for other modes to stand. . It is easily understood that FIG. 14 is the mode (511) in the same manner as FIG. 13 is the mode (431).

In conclusion, the electric field distribution (ie, the heating distribution) can be changed depending on the position of the opening 6.

For reference, when the food 5 is not in the heating chamber 3 and the heating chamber 3 is a rectangular parallelepiped, the heating chamber 3 can be considered as a cavity resonator. From the position of 6, a mode that can stand can be obtained. The dimensions of the heating chamber 3 are x, y, and z, and the number of modes that stand in each direction is a combination of m, n, and p that satisfies (Equation 4). (X,
y and z are in mm, m, n and p are integers)

[0095]

(Equation 4)

On the other hand, when there is the food 5, deviation from (Equation 4) occurs due to the influence of wavelength compression due to the dielectric constant of the food. However, even when the food 5 is present, it is experimentally found that the mode satisfying (Equation 4) is about to be established near the opening 6 and that the mode is often disturbed at a position away from the opening 6. Is coming. Therefore, as an example for establishing the mode (431) at λ ≒ 122 mm, (Equation 4)
X = 330 mm, y = 300 mm, z =
215mm etc. can be selected.

[0097]

As described above, the high-frequency heating device of the present invention has the following effects.

(1) Since a plurality of waveguides are adjacent to each other, they can be configured in a small space and with a small number of members. Therefore, reduction in size, weight, and price can be achieved.

(2) Since the waveguide branches at the node of the electric field,
Since the electromagnetic wave is efficiently transmitted into the waveguide after branching, and is also efficiently transmitted into the heating chamber through the plurality of openings, the heating efficiency is high. Therefore, the heating time can be short,
Since the waiting time of the user can be shortened and the consumption of extra power can be suppressed as much as possible, energy saving can be achieved, and the loss in the electromagnetic wave radiation part is reduced, so that the reliability is improved.

(3) Since the cross-sectional areas of the plurality of branched waveguides are small, they can be configured in a small space and with a small number of members. Therefore, similarly to (1), reduction in size, weight, and cost can be achieved. (4) The length of the branched waveguide is 1 of the guide wavelength λg.
Therefore, the electromagnetic wave can resonate at the guide wavelength λg even in the branched waveguide. Therefore, the electromagnetic wave is efficiently transmitted to the heating chamber through the plurality of openings, so that the heating efficiency is high. Therefore, there is the same effect as (2).

(5) Since the width of the branch point between the first waveguide and the branched waveguide is set to not more than 内 of the guide wavelength λg, the electromagnetic wave in the first waveguide in the resonance state can be reduced. It is also efficiently transmitted to the branched waveguide in the resonance state. Therefore, the electromagnetic wave is efficiently transmitted to the heating chamber through the plurality of openings, so that the heating efficiency is high. Therefore, there is the same effect as (2).

(6) Since the shielding portion shields the opening while being in contact with the projection on either the heating chamber, the waveguide, or at least one of the metal and the conductive member, the opening is shielded. Electromagnetic waves are not transmitted from between the shielding part and the protruding part, so that complete shielding can be achieved. Therefore, since the opening from which the electromagnetic wave is emitted can be accurately switched, the heating distribution can be freely changed, and an optimal heating distribution according to the purpose can be obtained. Therefore, any food can be heated uniformly.

Further, since leakage of electromagnetic waves from between the shielding portion and the protruding portion to the outside can be suppressed, it is safe, and malfunctions and the like can be prevented without noise problems for external devices and the like.

(7) Since the seal portion is constituted by either the heating chamber or the waveguide or a member fixed to at least one of them, no electromagnetic wave is transmitted from between the shielding portion and the opening. The leakage of electromagnetic waves to the outside is also suppressed. Therefore, there is the same effect as (6).

(8) Since a plurality of openings on the same wall are shielded or opened by one shield, the structure of the shield is simple and the number of components may be small. Therefore, there is an effect that the price can be reduced.

Further, even if the shielding portion does not move due to some accident, an opening is always opened, and electromagnetic waves are always supplied to the heating chamber. Therefore, there is no possibility that the electromagnetic wave does not enter the heating chamber because all the openings are shielded, abnormal loss and heat generation in the electromagnetic wave radiating portion and the waveguide hardly occur, and there is an effect of high safety and reliability.

(9) Since a single driving unit operates a shielding unit for shielding or opening a plurality of openings, the structure of the driving unit is simple and the number of parts may be small, or control is easy. There is an effect. Therefore, reduction in size, weight, and price can be achieved.

(10) Since the shielding unit is operated when the emission of the electromagnetic wave is stopped, the electric field is not disturbed during the operation of the shielding unit. Prevent outbreak. Therefore, it is safe and highly reliable, and it is possible to prevent a malfunction or the like without a problem of noise to an external device or the like.

(11) At the start of heating or at the end of heating,
Since the position of the shielding portion is set to be a light object to be heated or a position suitable for short-time heating, a short-time heating such as a light object to be heated is ready every time heating is started. Therefore, there is no failure in heating when a light object to be heated is put. On the other hand, when a thing requiring a long-time heating such as a large amount of objects to be heated is put in, it is sufficient to move the position of the shielding part to an appropriate position after starting the heating. After all, according to the present invention, when a light object to be heated is put in, an appropriate heating distribution can be given from the beginning of heating.

Further, when the light object to be heated is inserted, it is not necessary to operate the shielding part so much. Therefore, there is no power for moving the position of the shielding part and no loss during the operation of the shielding part.
Heating can be performed more efficiently, and time can be reduced. Therefore, there is the same effect as (2).

(12) At the start of heating or at the end of heating,
The drive unit is controlled so that the position of the object to be heated is either a light object to be heated or a position suitable for short-time heating. And the same effect as (11) is obtained.

(13) Since the output of the detecting section is not received or ignored for a while after the start of heating, the detecting section does not have to worry about erroneous detection when the electromagnetic wave in the initial stage of heating is unstable, and the stable state is maintained. Can be accurately detected. Therefore, the control based on the output of the detection unit is also accurate, and a highly reliable operation can be realized.

Further, since the initial state of the object to be heated is detected by the detecting section, there is no need to provide a period during which electromagnetic waves are not emitted for a while after the start, so that the object can be efficiently heated from the beginning. Therefore, the waiting time of the user can be shortened.

(14) Depending on the output of the detection unit, the shielding unit is operated a plurality of times during the period from the start of heating to the end of heating. This changes the heating distribution. Can be. Therefore, any object to be heated can be uniformly and efficiently heated.

(15) Depending on the output of the detection unit, the driving unit is controlled to change the position of the object to be heated a plurality of times from the start of heating to the end of heating. Appropriate heating can be performed according to the state of the object. Therefore, any object to be heated can be uniformly and efficiently heated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a high-frequency heating device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a high-frequency heating device according to another embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a high-frequency heating device according to another embodiment of the present invention.

FIG. 4A is a sectional view of a main part of a high-frequency heating device according to an embodiment of the present invention. FIG.

FIG. 5A is a sectional view of a main part of the high-frequency heating device. FIG.

FIG. 6 is a characteristic diagram of a high-frequency heating device according to another embodiment of the present invention.

FIG. 7 is a characteristic diagram of the high-frequency heating device.

FIG. 8 is a sectional view of a main part of the high-frequency heating device.

FIG. 9 is a characteristic diagram of the high-frequency heating device.

FIG. 10 is a sectional view of a main part of the high-frequency heating device.

11A is a characteristic diagram of a conventional high-frequency heating device. FIG. 11B is a characteristic diagram of a high-frequency heating device according to an embodiment of the present invention.

FIG. 12 is a perspective view of a high-frequency heating device according to the embodiment of the present invention.

FIG. 13 is a perspective sectional view of the high-frequency heating device.

FIG. 14 is a perspective sectional view of the high-frequency heating device.

FIG. 15 is a cross-sectional configuration diagram of a main part of the high-frequency heating device.

FIG. 16 is a sectional view of a conventional high-frequency heating device.

FIG. 17 is a cross-sectional view of another conventional high-frequency heating device.

FIG. 18 is a sectional view of another conventional high-frequency heating device.

FIG. 19 is a sectional view of another conventional high-frequency heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetron (electromagnetic radiation part) 2, 2A, 2B, 2C Waveguide 3 Heating chamber 4 Turntable 5 Food 6, 6A, 6B Opening 7 Branch point 10 Shielding part 12 Projection part 13 Seal part 14 Control part 15 Temperature detection Unit 16 Weight detection unit 17A, 17B Shape detection unit 20 Height drive unit

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI H05B 6/74 H05B 6/74 E (56) References JP-A-61-216296 (JP, A) JP-A-52-151951 (JP, A) JP, A) JP-A 55-100243 (JP, U) JP-A 61-188289 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 6/70 F24C 7/02 340 F24C 7/02 511 H05B 6/68 320 H05B 6/74

Claims (16)

(57) [Claims] A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, a first waveguide for transmitting an electromagnetic wave radiated from the electromagnetic wave radiating section, and a plurality of heating chambers in the heating chamber. A plurality of waveguides branched from the first waveguide and partially adjacent to each other to guide electromagnetic waves through the opening, and a control unit that controls operations such as emission of electromagnetic waves from the electromagnetic wave emission unit. A high-frequency heating device having a configuration. 2. The high-frequency heating apparatus according to claim 1, wherein a part of adjacent wall surfaces of the plurality of waveguides is shared. 3. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a first waveguide for transmitting electromagnetic waves radiated from the electromagnetic wave radiating section, and a plurality of heating chambers in the heating chamber. It has a plurality of waveguides that branch at an electric field node in the first waveguide to guide electromagnetic waves through the opening, and a control unit that controls operations such as emission of electromagnetic waves from the electromagnetic wave emission unit. High frequency heating device of the configuration. 4. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a first waveguide for transmitting electromagnetic waves radiated from the electromagnetic wave radiating section, and a plurality of heating chambers in the heating chamber. A plurality of waveguides branching from the first waveguide to guide the electromagnetic wave through the opening and having a cross-sectional area in a traveling direction of the electromagnetic wave smaller than a cross-sectional area of the first waveguide; A high-frequency heating device having a control unit for controlling operations such as emission of electromagnetic waves from the unit. 5. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a first waveguide for transmitting electromagnetic waves radiated from the electromagnetic wave radiating section, and a plurality of heating chambers in the heating chamber. In order to guide the electromagnetic wave through the opening, the first waveguide branches off from the first waveguide, and the length of the electromagnetic wave in the traveling direction from the branched position to the terminal portion is approximately an integral multiple of 0 or more of 1/2 of the guide wavelength λg. A high-frequency heating device having a configuration including a plurality of waveguides to be used and a control unit that controls operations such as emission of electromagnetic waves from the electromagnetic wave emission unit. 6. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a first waveguide for transmitting electromagnetic waves radiated from the electromagnetic wave radiating section, and a plurality of heating chambers in the heating chamber. A plurality of waveguides branching from the first waveguide at a width of about １ ／ or less of the guide wavelength λg from the first waveguide to guide the electromagnetic wave through the opening; and operations such as radiation of the electromagnetic wave from the electromagnetic wave radiation portion. A high-frequency heating device having a control unit for controlling the temperature. 7. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, and a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings. Made of metal or conductive to operate to shield or open at least a portion of the plurality of openings in the heating chamber or between the heating chamber and the waveguide or within the waveguide. A shielding portion having a property, and a projection portion formed on either the metal or conductive member fixed to at least one of the heating chamber and the waveguide so as to be in contact with the shielding portion, and the electromagnetic wave A high-frequency heating apparatus having a control unit that controls the emission of electromagnetic waves from the radiating unit and the operation of the shielding unit. 8. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, and a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings. Made of metal or conductive to operate to shield or open at least a portion of the plurality of openings in the heating chamber or between the heating chamber and the waveguide or within the waveguide. The heating part and / or the waveguide is fixed to at least one of the shielding part having the property and the electromagnetic wave leaking from between the shielding part and the plurality of openings shielded by the shielding part. A seal portion configured on any of the members,
A high-frequency heating apparatus having a control unit that controls emission of electromagnetic waves from the electromagnetic wave emission unit and operation of the shielding unit. 9. A heating chamber composed of a plurality of wall surfaces for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, and electromagnetic waves radiated from the electromagnetic wave radiating section through a plurality of openings. A waveguide for guiding into the heating chamber, and shielding or opening at least a plurality of openings on the same wall surface of the heating chamber in the heating chamber or between the heating chamber and the waveguide or in the waveguide. A high-frequency heating apparatus having a configuration comprising: a shielding unit made of metal or having conductivity so as to operate, and a control unit that controls emission of electromagnetic waves from the electromagnetic wave emitting unit and operation of the shielding unit. . 10. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, and a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings. A shield made of metal or conductive to operate to shield or open said plurality of openings in said heating chamber or between said heating chamber and said waveguide or in said waveguide. Part, one driving unit configured to either the heating chamber or the waveguide or a member fixed to at least one of the members to drive the shielding unit, and an electromagnetic wave from the electromagnetic wave radiation unit. A high-frequency heating device having a control unit that controls the driving unit that operates the radiation and the shielding unit. 11. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, and a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings. Made of metal or conductive to operate to shield or open at least a portion of the plurality of openings in the heating chamber or between the heating chamber and the waveguide or within the waveguide. Having a control unit that controls the emission of electromagnetic waves from the electromagnetic wave radiating unit and the operation of the shielding unit, wherein the control unit stops emitting electromagnetic waves from the electromagnetic wave radiating unit. A high-frequency heating device configured to operate the shielding unit. 12. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, and a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings. Made of metal or conductive to operate to shield or open at least a portion of the plurality of openings in the heating chamber or between the heating chamber and the waveguide or within the waveguide. Having a control unit that controls the emission of electromagnetic waves from the electromagnetic wave radiating unit and the operation of the shielding unit, wherein the control unit reduces the position of the shielding unit at the start of heating or at the end of heating. A high-frequency heating device configured to control an object to be heated or a position suitable for short-time heating. 13. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through an opening, and A driving unit that changes the position of the heating object or changes the distance between the object to be heated and a metal or a conductive member below the bottom of the object to be heated, and radiates electromagnetic waves from the electromagnetic wave emitting unit and the driving unit. And a control unit for controlling the operation, wherein the control unit controls the drive unit so that the position of the object to be heated becomes a position suitable for heating a lightweight object or a short time at the start of heating or at the end of heating. A high-frequency heating device configured to be controlled. 14. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a waveguide for guiding electromagnetic waves radiated from the electromagnetic wave radiating section through the opening into the heating chamber, A detection unit that detects a physical quantity of a heating object or a state in the heating chamber and a change thereof, and a control unit that receives an output of the detection unit and controls emission of electromagnetic waves from the electromagnetic wave emission unit, the control unit Is a high-frequency heating apparatus having a configuration in which the output of the detection unit is not received or ignored for a while after the start of heating by the emission of the electromagnetic wave from the electromagnetic wave emission unit. 15. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating an electromagnetic wave, and a waveguide for guiding the electromagnetic wave radiated from the electromagnetic wave radiating section into the heating chamber through a plurality of openings. A shield made of metal or conductive to operate to shield or open said plurality of openings in said heating chamber or between said heating chamber and said waveguide or in said waveguide. Unit, a detection unit for detecting a physical quantity of the object to be heated or a state in the heating chamber and a change thereof, and receiving an output of the detection unit, controlling emission of electromagnetic waves from the electromagnetic wave emission unit and operation of the shielding unit. A high-frequency heating apparatus having a control unit, wherein the control unit operates the shielding unit a plurality of times from the start of heating to the end of heating depending on the output of the detection unit. 16. A heating chamber for taking in and out an object to be heated, an electromagnetic wave radiating section for radiating electromagnetic waves, a waveguide for guiding electromagnetic waves radiated from the electromagnetic wave radiating section through the opening into the heating chamber, A driving unit that changes the position of the object to be heated or changes the distance between the object to be heated and a metal or a conductive member below the bottom of the object to be heated, and the physical quantity of the object to be heated or the state in the heating chamber and its change And a control unit that receives the output of the detection unit and controls the emission of electromagnetic waves from the electromagnetic wave emission unit and the operation of the driving unit, and the control unit is configured to output the output of the detection unit. Is a high-frequency heating device configured to operate the driving unit a plurality of times from the start of heating to the end of heating.