JP4457430B2 - High frequency heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating apparatus that heats an object to be heated such as food, and more particularly to a device that changes a standing wave distribution in a heating chamber to eliminate uneven heating.
[0002]
[Prior art]
A conventional high-frequency heating apparatus will be described with reference to the drawings. FIG. 8 is a schematic configuration diagram of a high-frequency heating device. 1 is a main body of a high-frequency heating apparatus, 2 is a magnetron which is a high-frequency generating means for generating microwaves, 3 is a waveguide for guiding microwaves generated from the magnetron, 4 is a heating chamber for storing a heated object such as food, 5 A mounting table 6 on which the object to be heated is mounted is a turntable support that supports the turntable 5. 7 is a motor for rotating the turntable support 6, and 8 is a control means for controlling the magnetron 2 and the motor 7.
[0003]
In the case of heating, an object to be heated such as food is placed on the turntable, and the phenomenon that moisture contained in the object to be heated absorbs microwaves and self-heats is used.
[0004]
In the heating chamber of the conventional high-frequency heating apparatus, the microwave radiated from the high-frequency generating means propagates while repeating reflection on the metal wall surface forming the heating chamber to form a standing wave distribution in the heating chamber. Since the generated standing wave distribution in the heating chamber hardly changes, the object to be heated in the region where the microwave intensity is strong is easily heated, and the object to be heated in the region where the microwave intensity is weak is hardly heated. Therefore, uneven heating occurs in the object to be heated.
[0005]
In the conventional technique, a method of rotating the object to be heated is employed in order to eliminate uneven heating of the object to be heated.
[0006]
[Problems to be solved by the invention]
However, in the conventional technique, the method of rotating the object to be heated hardly changes the standing wave distribution in the heating chamber, and the object to be heated is heated while repeatedly passing through the constant standing wave distribution. Therefore, there is a problem that the heating area of the object to be heated is generated concentrically.
[0007]
The present invention solves such a problem, and a high-frequency heating device that eliminates uneven heating of an object to be heated by changing the standing wave distribution generated in the heating chamber by changing the flow of the microwave propagating in the heating chamber. The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, a high-frequency heating device according to the present invention includes a heating chamber that houses an object to be heated, a mounting table that is provided in the heating chamber and mounts the object to be heated, and rotationally drives the mounting table. Provided on a first drive means, a high frequency generating means for generating a high frequency radiated into the heating chamber, a power supply port for radiating a high frequency generated by the high frequency generating means to the heating chamber, and a wall surface forming the heating chamber An opening, a groove having one end as the opening, an impedance variable means made of a non-metallic material provided in the groove and rotated to vary the impedance of the opening, and the impedance variable means is rotationally driven. Second driving means, and control means for controlling the operation of the first driving means and the second driving means.
[0009]
And the flow of the microwave which propagates in a heating chamber can be changed by changing the flow of the high frequency current of a heating chamber wall surface by an impedance variable means. Thereby, the uneven heating of the object to be heated can be eliminated by rotating the object to be heated while changing the standing wave distribution in various ways.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The high-frequency heating device of the present invention includes a heating chamber for storing an object to be heated, a mounting table provided in the heating chamber for mounting the object to be heated, first driving means for rotationally driving the mounting table, and the heating A high frequency generating means for generating a high frequency radiated into the room, a power supply port for radiating a high frequency generated by the high frequency generating means to the heating chamber, an opening provided on a wall surface forming the heating chamber, and the opening A groove portion as one end; an impedance variable means made of a non-metallic material provided in the groove portion and driven to rotate to vary the impedance of the opening; a second drive means for rotating the impedance variable means; Control means for controlling the operation of the first drive means and the second drive means is provided.
[0011]
And the flow of the microwave which propagates in a heating chamber can be changed by changing the flow of the high frequency current of a heating chamber wall surface by an impedance variable means. Thereby, the uneven heating of the object to be heated can be eliminated by rotating the object to be heated while changing the standing wave distribution in various ways.
[0012]
Moreover, the further provided detection means for detecting the weight of the object to be heated, based-out to the control means a detection signal of said detecting means, if or when the object to be heated to be heated amount is small is small, the rotation of the table It is synchronized with the rotational speed of the speed and the variable impedance unit, if the target object is a large plurality or when the object to be heated is you rotational speed of the mounting table and the rotational speed of said impedance varying means asynchronously .
[0013]
And if each rotational speed is synchronized, a specific area | region will be heated strongly to the to-be-heated object for every circumference | surroundings of to-be-heated object, and a heating area | region will be disperse | distributed if it makes it asynchronous. Thus, the object to be heated can be optimally uniformly heated according to the type, amount, and shape of the object to be heated.
[0014]
The control means is characterized in that the rotation speed of the impedance variable means is increased with respect to the rotation speed of the mounting table.
[0015]
Thereby, since the heating region can be dispersed by quickly changing the standing wave distribution, it is possible to easily promote uniform heating of a heated object having a high height or a heated object having a large bottom area.
[0016]
Further, the control means has a control mode in which only the first driving means is operated.
[0017]
Thereby, a to-be-heated material can be heated in specific standing wave distribution. For example, in the case of a standing wave distribution that generates a strong electric field distribution in the center of the heating chamber, heating can be accelerated in a short time using this control mode for a small object to be heated.
[0018]
Further, the control means has a control mode in which only the second drive means is operated.
[0019]
Thereby, even when it is difficult to rotate the object to be heated due to the shape of the object to be heated, the object to be heated is uniformly heated by changing the standing wave distribution by operating the second driving means. Can do.
[0020]
Further, the apparatus user can designate the rotation operation and stop operation of the first drive means, and the rotation operation and stop operation at the desired rotation angle of the second drive means.
[0021]
Thereby, since a user can select a favorite heating mode, a user can select heating only rice, for example with respect to heating of mixed foodstuffs, such as a lunch box.
[0022]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0023]
Example 1
FIG. 1 is a schematic configuration diagram of a high-frequency heating device showing a first embodiment of the present invention, and FIG. 2 is an external view of the high-frequency heating device of FIG.
[0024]
1 and 2, reference numeral 10 denotes a high-frequency heating apparatus main body, 11 a magnetron which is a high-frequency generating means for generating microwaves, 12 a waveguide for guiding microwaves from the magnetron 11, and 13 heating for housing an object to be heated. In the chamber, the wall surface is made of metal. Reference numeral 14 denotes a mounting table on which an object to be heated is mounted, 15 is a mounting table support that supports the mounting table 14, and 16 is a first motor that is a first driving means that rotationally drives the mounting table support 15. Reference numeral 17 denotes a power supply port that radiates microwaves generated from the magnetron 11 into the heating chamber 13. Reference numeral 18 denotes an opening provided on the wall surface 19 in the heating chamber 13, and 20 denotes a groove having the opening 18 as one end. Reference numeral 21 denotes impedance varying means for varying the impedance of the opening 20 and is constituted by a dielectric plate 21 that is a non-metallic material. The dielectric plate 21 is preferably made of a low dielectric loss material made of, for example, a glass, ceramic or resin material having a relative dielectric constant of around 10, and has protrusions at both ends and protrusions in the holes provided in the groove 20. It is fitted and supported by rotation. Reference numeral 22 denotes a second motor as driving means for driving the dielectric plate 21. As a method of driving the dielectric plate 21, a stepping motor may be used as the second motor, and the dielectric plate 21 may be rotated stepwise by a certain angle, or may be continuously rotated using a general-purpose motor. It doesn't matter. Reference numeral 23 denotes control means for controlling the magnetron 11, the first motor 16, and the second motor 22.
[0025]
Next, the operation in the above configuration will be described. In the case of heating, a heated object such as food is placed on the turntable 14. When heating, heating information is sent to the control means 23 from a signal such as a heating switch (not shown). Based on this heating information, the control means 23 sends signals to the magnetron 11, the first motor 16 and the second motor 22, respectively. The microwave generated by the magnetron 11 by the signal from the control means 23 propagates through the waveguide 12 and is radiated from the power supply port 17 into the heating chamber 13. Further, the operations of the first motor 16 and the second motor 22 are controlled based on the heating information, and an optimal standing wave distribution is generated in the heating chamber to heat the object to be heated.
[0026]
The operation of the dielectric plate 21 during heating is controlled by a signal from the control means 23 such as continuous rotation, stop for a certain time at a specific rotation angle, or repeat rotation / stop in a predetermined combination. The groove depth of the groove 20 is such that the impedance generated in the opening 18 is extremely small (ideally when the dielectric plate 21 is perpendicular to the bottom surface of the heating chamber 13 (the rotation angle at this time is 0 °). Is zero). Therefore, when the rotation angle of the dielectric plate 21 is 0 °, a high-frequency current flows through the wall surface 19, and the same distribution as the standing wave distribution that occurs when the opening 18 is not provided in the wall surface 19 occurs. On the other hand, when the direction of the dielectric plate 21 is horizontal with respect to the bottom surface of the heating chamber 13 (the rotation angle at this time is 90 °), the impedance of the opening 18 is large and the high-frequency current flowing through the wall surface 19 is disturbed. . Therefore, a standing wave distribution different from the standing wave distribution generated when the opening portion 18 is not provided in the wall surface 19 is generated. That is, when the rotation angle is changed, the impedance of the opening 18 changes, and the standing wave distribution in the heating chamber 13 changes.
[0027]
In the present embodiment, the method for expressing the rotation angle of the dielectric plate 21 is an angle in the direction in which the upper half of the dielectric plate 21 is inclined toward the heating chamber with reference to the case where the dielectric plate 21 is vertical. It was.
[0028]
1 and 2 of this embodiment, the rotation angle of the dielectric plate 21 is 0 °. Further, although the opening 18 is arranged so that the major axis direction is parallel to the depth direction, the opening 18 may be arranged so that the major axis direction is parallel to the height direction. Further, the opening 18 may be disposed anywhere as long as it is the wall surface of the heating chamber 13, or a plurality of openings 18 may be disposed.
[0029]
Since heated objects such as foods are more likely to be heated as they are located in a region where microwaves are concentrated, in order to eliminate uneven heating of the heated object, in addition to rotating a conventional mounting table, a stationary It is necessary to perform control such as making the wave distribution uniform or alternately generating the intensity of the microwave at the same position.
[0030]
In this example, when 200 g of Adhair Synthetic Glue (registered trademark) manufactured by Sekisui Resin Co., Ltd. is placed in a container having a bottom of 100 mm × 100 mm to be heated, the rotation of the mounting table 14 is stopped. FIG. 3 shows the result of temperature distribution when the dielectric plate 21 is heated by the high-frequency heating device of the present invention with the rotation angle of the dielectric plate 21 fixed at 0 °, 45 °, and 90 °.
[0031]
The temperature distribution in FIG. 3 indicates that the shaded area is a high temperature portion.
[0032]
In addition, Adhair synthetic glue (registered trademark) is a polyvinyl alcohol aqueous solution, which is transparent at normal temperature, but has a property of becoming cloudy when the temperature is 45 ° C. or higher.
[0033]
As described above, the temperature distribution of the object to be heated was changed by changing the rotation angle of the dielectric plate 21.
[0034]
Thereby, various standing waves are generated in the heating chamber by controlling the rotation of the dielectric plate 21, and further, the heating unevenness of the object to be heated can be eliminated by adding the rotation control of the mounting table 14. .
[0035]
(Example 2)
Next, a second embodiment of the present invention will be described.
1 and 2, reference numeral 24 denotes first detection means for detecting the weight of the object to be heated. Note that the same reference numerals as those in the first embodiment have the same functions, and a description thereof is omitted.
[0036]
Next, the operation will be described. The control unit 23 controls the magnetron 11, the first motor 16, and the second motor 22 based on the signal from the first detection unit 24. At this time, the control means 23 synchronizes the rotation speed of the mounting table 24 and the rotation speed of the impedance variable means 21 or makes them asynchronous. When the object to be heated is heated, if the rotation speed of the mounting table 24 and the rotation speed of the impedance variable means 21 are synchronized, the object to be heated is strongly heated in a specific area every time the object is heated. Therefore, when the amount of the object to be heated is small or the object to be heated is small, it can be heated intensively and can be heated quickly. Conversely, when the rotational speed of the mounting table 24 and the rotational speed of the impedance varying means 21 are made asynchronous, the heating area is dispersed. Therefore, when there are a large number of objects to be heated or when the objects to be heated are large, the whole can be heated uniformly.
[0037]
In this example, when 200 g of the above-mentioned Adhair Synthetic Glue (registered trademark) is put into a container having a bottom of 100 mm × 100 mm to be heated, the rotational speed of the mounting table 24 and the rotational speed of the impedance variable means 21 are calculated. FIG. 4 shows the result of the heating distribution when heated by the high-frequency heating device of the present invention in the case of being synchronized and in the case of being asynchronous.
[0038]
As shown in FIG. 4, when the rotation speed of the mounting table 24 and the rotation speed of the impedance variable means 21 are synchronized, a specific region of the object to be heated is strongly heated, and a part that is not easily heated is generated in the surrounding part. When asynchronous, the heating area is dispersed and the surroundings are heated almost uniformly. In FIG. 4, 1: 1/2 synchronization means that the mounting table is rotated twice with respect to one rotation of the impedance variable means. As described above, the object to be heated is optimally uniformly heated by synchronizing the rotation speed of the mounting table 14 and the rotation speed of the impedance variable means 21 according to the type, amount and shape of the object to be heated. can do.
[0039]
(Example 3)
Next, a third embodiment of the present invention will be described. The configuration is the same as in the second embodiment.
[0040]
Next, the operation will be described. 1 and 2, the control means 23 controls the first motor 22. At this time, the control means 23 performs control so that the rotation speed of the impedance variable means 21 is higher than the rotation speed of the mounting table 14.
[0041]
In this embodiment, when 200 g of water is put into a container with an inner diameter of 72 mm to be heated, the change in temperature of water with respect to the rotation speed of the impedance variable means 21 is shown in FIG. The rotation speed of the mounting table was 6 rotations per minute. In FIG. 5, the white circle is 5 mm from the bottom, and the black circle is 5 mm from the top surface. From FIG. 5, it is possible to reduce the temperature difference between the upper and lower sides by increasing the rotational speed of the impedance varying means 21. That is, the temperature difference between the upper and lower sides was about 20 ° C. at 3 revolutions per second, but the temperature difference was reduced to about 10 ° C. by half at 1000 revolutions per second. Therefore, by increasing the rotational speed of the impedance varying means 21 relative to the rotational speed of the mounting table 14, it is possible to promote uniform heating of the heated objects in the vertical direction when heating milk, liquor, coffee, or the like.
[0042]
In addition, since the control of the impedance varying means 21 can disperse the heating region by quickly changing the standing wave distribution in the heating chamber, it is possible to easily promote uniform heating of the heated object having a large bottom area.
[0043]
Example 4
Next, a fourth embodiment of the present invention will be described.
[0044]
In FIGS. 1 and 2, reference numeral 25 denotes second detection means for determining the rotation angle of the dielectric plate 21, and reference numeral 26 denotes an operation unit for selecting the type of the object to be heated. In addition, the thing of the same code | symbol as Example 1 thru | or 3 has the same function, and abbreviate | omits description.
[0045]
Next, the operation will be described. The second motor 22 rotates and moves the dielectric plate 21 step by step by a certain angle. The second detection means 25 detects the state where the dielectric plate 21 has a rotation angle of 0 °. Then, with the rotation angle of 0 ° as a reference, the rotation angle of the dielectric plate 21 is controlled to a specified angle based on the number of steps rotated by a signal from the control means 23. The control unit 23 controls the magnetron 11, the first motor 16, and the second motor 22 based on signals input from the first detection unit 24 and the operation unit 26. After the second motor 22 immediately rotates the dielectric plate 21 of the impedance varying means 21 to a desired rotation angle, the second motor 22 stops and only the mounting table 14 rotates to heat the object to be heated. In this embodiment, when the rotation angle of the dielectric plate 21 is 0 °, 45 °, and 90 °, the experimental results of the microwave input power to 200 g and 400 g of water to be heated are shown in FIG. As shown in FIG. 6, the input power of the microwave to water varies depending on the angle of the dielectric plate 21. Accordingly, when it is desired to quickly heat a small amount of a liquid object to be heated, for example, a drink for 1 to 2 cups, the angle of the dielectric plate 21 may be fixed at 45 °. In this case, due to the relationship with Example 3 described above, the temperature unevenness in the vertical direction is somewhat higher than that in the case where the dielectric plate 21 is rotated at a high speed. Therefore, the method of this embodiment is particularly effective when priority is given to the heating time.
[0046]
In this embodiment, 200 g of the above-mentioned Adhair Synthetic Glue (registered trademark) is put into a container having a bottom surface of 100 mm × 100 mm to be heated, and the rotation angle of the dielectric plate 21 is set to 0 °, 45 °, and 90 °. FIG. 7 shows the result of heating distribution when the mounting table is rotated while being fixed. In FIG. 7, the white area | region has shown the area | region heated. From FIG. 7, when the mounting table is rotated in a state where the rotation angle of the dielectric plate 21 is fixed, the heating distribution can be changed depending on the rotation angle of the dielectric plate 21. Accordingly, when heating an object to be heated that heats up first, for example, Chinese buns with sauce, the rotation angle of the dielectric plate 21 is fixed at 0 ° or 90 ° so that the central heating is weakened. The temperature difference from the outside can be improved.
[0047]
(Example 5)
Next, a fifth embodiment of the present invention will be described.
[0048]
In FIGS. 1 and 2, reference numeral 26 denotes an operation unit that selects the type of object to be heated, and 27 denotes heaters provided above and below the heating chamber 13. In addition, the thing of the same code | symbol as Example 1 thru | or 4 has the same structure, and abbreviate | omits description.
[0049]
Next, the operation will be described. The control unit 23 controls the magnetron 11, the second motor 22, and the heater 27 based on signals input from the first detection unit 24 and the operation unit 26. When the object to be heated and the container to be heated enter the heating chamber 13 but are larger than the mounting table 14 and difficult to rotate, the operation of the mounting table 14 is stopped and only the impedance variable means 21 is operated to be fixed. A uniform temperature distribution is heated by changing the wave distribution. At this time, the impedance variable means 21 may be controlled continuously or intermittently. For example, if it is difficult to rotate a part of the tail when the whole fish is heated, it is difficult to rotate the mounting table, and only the impedance variable means is driven to perform uniform heating. it can. Furthermore, it is also possible to select the oven and grill menus with the operation unit 26 and place the object to be heated on a square oven dish so that the microwaves can be uniformly irradiated while heating the heater.
[0050]
(Example 6)
Next, a sixth embodiment of the present invention will be described.
[0051]
In FIGS. 1 and 2, reference numeral 28 denotes an operation unit that selects an operation mode of the mounting table 14 and the impedance varying means 21. In addition, the thing of the same code | symbol as Example 1 thru | or 5 has the same structure, and abbreviate | omits description.
[0052]
Next, the operation will be described. The control unit 23 controls the magnetron 11, the first motor 16, and the second motor 22 by a signal input from the operation unit 28. Thereby, since the apparatus user can select a preferred heating mode with the operation unit 28, the heating of the mounting table 14 is stopped and the impedance variable means 21 is intentionally used for heating the mixed food such as a lunch box. For example, only rice can be heated under the intentional standing wave distribution.
[0053]
【The invention's effect】
As described above, the present invention has the following effects.
[0054]
According to the high frequency heating device of the present invention, the impedance of the opening is varied by rotationally driving the impedance variable means, and the flow of the high frequency current on the wall surface having the opening is changed, thereby standing waves in the heating chamber. The distribution can be changed. Thereby, the heating unevenness of a to-be-heated material can be eliminated.
[0055]
In addition, by synchronizing or rotating the rotation speed of the mounting table and the rotation speed of the impedance variable means, a specific area of the object to be heated can be heated intensively, or conversely, the heating area can be dispersed. Thereby, it can heat uniformly according to the quantity and shape of a to-be-heated material.
[0056]
Moreover, the heating area | region of a to-be-heated material can be disperse | distributed by controlling so that the rotational speed of an impedance variable means may become faster than the rotational speed of a mounting base. Thereby, the to-be-heated object with a large bottom area can be heated uniformly. Further, the temperature unevenness in the vertical direction can be suppressed for a heated object having a height.
[0057]
In addition, the user can heat the object to be heated under a state in which a specific standing wave distribution is formed by maintaining the impedance variable means at a certain angle by selecting the type of the object to be heated by the selecting means. it can. Thereby, a microwave can be selectively concentrated or disperse | distributed according to the kind of to-be-heated material.
[0058]
In addition, the user can stop the rotation of the mounting table by selecting the type of the object to be heated by the selection means, and drive the impedance variable means to change the standing wave distribution in the heating chamber. Thereby, the heating distribution of the object to be heated which is difficult to rotate can be changed, and uneven heating can be eliminated. Moreover, when microwave heating is simultaneously performed during cooking using a square plate, heating unevenness due to microwaves can be eliminated.
[0059]
Further, the user can select each operation of the mounting table and the impedance variable means by the selection means. Thereby, since the user can select a favorite heating mode, for example, only the rice of the mixed food such as a lunch box can be partially heated.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a high-frequency heating device according to a first embodiment of the present invention. FIG. 2 is an external perspective view of the high-frequency heating device according to the first embodiment of the present invention. FIG. 4 is a temperature distribution characteristic diagram of an object to be heated with respect to each rotation angle of the impedance variable means when the mounting table is stopped according to the embodiment. FIG. 5 is a temperature characteristic diagram of water load in the vertical direction with respect to the rotation speed of the impedance varying means of the third embodiment of the present invention. FIG. 6 is a diagram of the temperature varying characteristic of the impedance varying means of the fourth embodiment. The figure which shows the input electric power to the water load when a mounting base is rotated with respect to each rotation angle. [FIG. 7] Rotate a mounting base with respect to each rotation angle of the impedance variable means of the 4th Example of this invention. Fig. 8 Conventional distribution of heat distribution Schematic cross-sectional view of the heating apparatus [Description of symbols]
11 Magnetron (high frequency generation means)
13 Heating chamber 14 Mounting table 16 First motor (first driving means)
17 Feed port 18 Opening portion 20 Groove portion 21 Impedance varying means 21 Dielectric plate 22 Second motor (second driving means)
23 Control means 26, 28 Operation unit

Claims (6)

  A heating chamber for storing an object to be heated, a mounting table provided in the heating chamber for mounting the object to be heated, first driving means for rotationally driving the mounting table, and a high frequency radiated in the heating chamber are generated. A high-frequency generator, a power supply port for radiating a high-frequency generated by the high-frequency generator to the heating chamber, an opening provided in a wall surface forming the heating chamber, a groove having the opening as one end, and the groove An impedance variable means made of a non-metallic material that is rotationally driven to vary the impedance of the opening, a second drive means that rotationally drives the impedance variable means, a first drive means, and a second drive A high-frequency heating apparatus comprising control means for controlling the operation of the means. The further include detecting means for detecting the weight of the object to be heated, based-out the detection signal of the control means said detecting means, if or when the object to be heated to be heated amount is small is small, the rotational speed of the table It is synchronized with the rotational speed of the variable impedance unit, if the target object is a large plurality of cases and the heated object is a rotating speed of the mounting table and the rotational speed of said impedance varying means asynchronously The high-frequency heating device according to claim 1.   3. The high frequency heating apparatus according to claim 2, wherein the control means increases the rotation speed of the impedance variable means with respect to the rotation speed of the mounting table.   2. The high frequency heating apparatus according to claim 1, wherein the control means has a control mode in which only the first drive means is operated.   The high frequency heating apparatus according to claim 1, wherein the control means has a control mode in which only the second drive means is operated. And rotation and stopping operation of the first driving means, high-frequency heating apparatus according to claim 1, wherein the rotating operation and the desired rotation angle in the stop operation and the device user of the second drive means has a structure that can be specified.

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