JP3745588B2 - High frequency heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating apparatus that performs dielectric heating by irradiating an object to be heated contained in a heating chamber with a high frequency.
[0002]
[Prior art]
FIG. 5 is a longitudinal sectional view of a main part in a conventional high-frequency heating apparatus. In the figure, reference numeral 1 denotes a substantially box-shaped heating chamber having an opening on the front surface, which is formed in the main body of a high-frequency heating device (not shown) having an opening on the front surface. 1a is a right side plate of the heating chamber 1, and a power supply port 2 is provided at the upper part and the lower part.
[0003]
Reference numeral 3 denotes a high-frequency oscillator that is provided on one side of the heating chamber 1 and oscillates a high frequency in a frequency band from 300 MHz to 30 GHz. Reference numeral 4 denotes an antenna of the high-frequency transmitter 3, which is disposed inside the waveguide 5 that communicates with the power supply port 2. In order to propagate the high frequency from the high frequency oscillator 3 and the antenna 4 to the heating chamber 1, the waveguide 5 is provided between the high frequency oscillator 3 and the right side plate 1 a of the heating chamber 1.
[0004]
Reference numeral 6 denotes a mounting table on which the object to be heated 7 is mounted, which is formed in a substantially disc shape by a low dielectric constant material such as glass. Reference numeral 8 denotes a rotary plate that supports a mounting table 6 rotatably provided in the vicinity of the bottom plate 1b of the heating chamber 1, and is formed in a substantially disk shape from a metal material. The rotary plate 8 is connected to a motor 9 provided at the lower portion of the heating chamber 1 via a shaft portion 9a.
[0005]
A door (not shown) that can be opened and closed is attached to the front surface of the main body of the high-frequency heating device. The door and the opening of the heating chamber 1 are appropriately closed by this door. An operation panel (not shown) on which a display unit, operation buttons, and the like are arranged is provided on the right side of the front surface of the main body.
[0006]
Next, the operation will be described.
When cooking the object to be heated 7, first, the door is opened, the object to be heated 7 is placed on the mounting table 6 installed in the heating chamber 1, and the door is closed. Next, the cooking menu is selected by the operation panel provided on the main body, the cooking time is set, and cooking is started. By this start, the high-frequency oscillator 3 operates and oscillates a high frequency.
This high frequency propagates through the waveguide 5 via the antenna 4 and is radiated into the heating chamber 1 from the two power supply ports 2. At the same time, the motor 9 is operated to rotate the rotary plate 8, the mounting table 6 supported by the rotary plate 8, and the heated object 7.
[0007]
The high frequency wave radiated into the heating chamber 1 is diffused in the heating chamber 1, sequentially reflected by the wall surface in the heating chamber 1, and irradiated on the object 7 to be heated. Thereby, the article 7 to be heated is heated.
[0008]
The conventional high-frequency heating apparatus is configured as described above, and since the shape and position of the power supply port and the waveguide are fixed, the standing wave distribution in the heating chamber is also fixed. For this reason, heating unevenness has been reduced by moving and rotating the object to be heated across a place where the electric field strength is strong and a place where the object is strong in the standing wave distribution fixed using the rotary plate 8.
[0009]
However, simply rotating the rotary plate 8 does not completely eliminate the heating unevenness, and there is a problem that the central portion tends to be insufficiently heated especially on the concentric circles.
[0010]
In order to solve such a problem, for example, Japanese Patent Application Laid-Open No. 7-269881 discloses a technique for changing the position of the power supply port. FIG. 6 is a longitudinal sectional view of a main part of the high-frequency heating apparatus disclosed therein.
[0011]
In the figure, reference numeral 13 denotes a circular opening, which is closed by a disk 14 having substantially the same size. The disk 14 has an opening 15 and is driven to rotate by a disk motor (not shown). Here, the disk motor is a stepping motor or a servo motor, and the opening 15 is disposed at an appropriate position around the rotation axis of the disk motor. The opening 15 arranged in this manner serves as a power feeding port, and radiates high frequency from the high frequency transmitter into the heating chamber 1.
[0012]
[Problems to be solved by the invention]
The conventional high-frequency heating apparatus is configured as described above, and the heating unevenness is large. Further, in the high-frequency heating apparatus disclosed in Japanese Patent Application Laid-Open No. 7-269881 aimed at improving this, since the area of the opening 14 of the disk is small with respect to the opening 13 of the waveguide, the high frequency is efficiently introduced into the heating chamber. There was a problem that it was not possible to propagate and heating efficiency was low. Furthermore, since the waveguide path does not change, there is no change in the standing wave distribution in the waveguide. Therefore, a large change in the standing wave distribution in the heating chamber cannot be expected, and it is difficult to significantly improve heating unevenness. .
[0013]
The present invention has been made in order to solve the above-described problems, and has an object to provide a high-frequency heating device with little heating unevenness and high heating efficiency, that is, satisfying both uniform heating and speed heating. Is.
[0014]
[Means for Solving the Problems]
A high-frequency heating device according to the present invention includes a heating chamber that houses an object to be heated, a high-frequency oscillator, a waveguide that propagates high-frequency waves oscillated from the high-frequency oscillator into the heating chamber, and a back surface of the heating chamber. A power supply port serving as a boundary between the waveguide and the heating chamber is provided. A part of the wall surface of the waveguide connected to the power supply port is a movable wall, and driving means for rotating or moving the movable wall is provided. The shape of the mouth and the waveguide is changed at the same time, and detecting means for detecting the heating state of the object to be heated is provided, and the object to be heated is provided by the driving means based on a signal from the detecting means. The number of the power supply ports is singular, the movable wall is a column that substantially matches the shape of the power supply port, and the height is substantially the same as the height of the cross section of the waveguide. A mover formed so that the mover is In which flat sides of the body is to function as a movable wall of the waveguide.
[0015]
The power feeding port is a single, the movable wall is a column that substantially matches the shape of the power feeding port, and the height is a mover formed so as to substantially match the height in the cross section of the height of the waveguide, The mover is such that the flat side surface of the column functions as a movable wall of the waveguide .
[0016]
In addition, a plurality of mounting tables arranged substantially in parallel with the bottom plate of the heating chamber, and a detecting means for detecting the heating status of the object to be heated mounted on each mounting table are provided in the heating chamber, Based on the signal, the movable wall is rotated or moved by the driving means to control the high-frequency irradiation to each object to be heated.
[0017]
Input means for inputting information on the type and shape of the object to be heated is provided, and the driving means controls the high-frequency irradiation on the object to be heated based on a signal from the input means. .
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a perspective view of an essential part in Embodiment 1 of the present invention. Portions that are the same as or equivalent to those of the prior art are denoted by the same reference numerals, and description thereof is omitted.
[0019]
In the figure, a circular power supply port 16 is provided at substantially the center of the back plate 1 e of the heating chamber 1 so as to cover the power supply port 16 along the back plate 1 e so as to guide the high frequency from the antenna 4 to the power supply port 16. Is provided with a waveguide 5.
[0020]
Reference numeral 17 denotes a mover, which forms part of the wall surface of the waveguide connected to the power supply port 16. More specifically, the mover 17 is a column having a semicircular or fan-shaped cross section that is substantially the same as the shape of the power supply port 16 and has a cross-sectional shape that is substantially the same as the height in the cross-section of the waveguide. I'm doing it. Therefore, the flat side surface of this column functions as a movable wall of the waveguide. The mover 17 passes through the center of the circular power supply port 16, is fixed to an axis perpendicular to the surface, and is configured to rotate around the axis by a motor. Here, a stepping motor, a servo motor, or the like is used as the motor to finely control the position of the mover 17.
[0021]
A rotary plate that rotates the object 7 and the mounting table 6 is rotated on the bottom of the heating chamber, an openable / closable door that closes the main body and the opening of the heating chamber 1 on the front side, and an operation panel on the right side of the front. The attachment point is as described in the conventional example.
[0022]
In the configuration as described above, the object 7 to be heated is set on the mounting table 6 in the heating chamber 1, the door is closed, the cooking time is set from the operation panel, and the high frequency oscillator 3 is started. A high frequency wave propagates through the antenna 4 through the waveguide 5 whose shape has been changed by the mover 17 and is further radiated into the heating chamber 1 from the power supply port 16 whose shape has been changed by the mover 17.
[0023]
The high frequency wave radiated into the heating chamber 1 is diffused in the heating chamber 1 and directly irradiates the object 7 to be heated, and the wall surface of the heating chamber 1, that is, the right side plate 1a, the bottom plate 1b, the left side plate 1c, and the top plate 1d. The back plate 1e and the front plate 1f that is in a positional relationship facing the back plate 1e when the front door is closed are sequentially reflected to indirectly irradiate the object 7 to be heated. The heated object 7 is heated by both the direct irradiation and the indirect irradiation.
[0024]
Here, since the mover 17 is rotated, the shape of the power feeding port changes with the shape of the waveguide 5 through which the high frequency is propagated, and a plurality of standing wave distributions exist in the heating chamber 1. . For this reason, the to-be-heated material 7 is heated by several irradiation patterns, and a heating nonuniformity is improved.
[0025]
As described in Japanese Patent Application Laid-Open No. 7-269881, a part of the high-frequency energy propagating in the waveguide is not extracted and used, but all of the high-frequency energy is absorbed. The amount increases and speed heating becomes possible.
[0026]
Here, the liquid to-be-heated object 7 such as milk, sake lees, etc. is rotated by moving the mover 17 upward, so that a high frequency is generated in the lower part of the heating chamber 1 from the waveguide 5 and the feeding port moved downward. Radiation, intensive heating of the lower part of the article 7 to be heated, and uniform heating of the entire body by convection allow speed heating. In addition, by rotating the mover 17 downward on a large object 7 to be heated such as pizza, high-frequency waves are emitted upward from the heating chamber 1 through the waveguide 5 and the power supply port that have moved upward. The upper surface of the heated object 7 can be heated as a whole and heated substantially uniformly. In this way, if the relationship between the shape and type of the object to be heated and the movement / position of the mover is programmed in advance, the user can heat the object 7 to be heated almost uniformly by a simple operation of the operation panel.
[0027]
Furthermore, a detection means for detecting the finish (heating state) of the article 7 to be heated is provided in the heating chamber 1 so that the high-frequency radiation is intensively applied to the underheated part while monitoring the finish state of the article 7 to be heated. Further, if the mover 17 is controlled, finer and uniform heating can be realized.
[0028]
In the first embodiment, the case where the power supply port is installed at the center of the wall surface is shown. However, even when the power supply port is not at the center, the standing wave distribution in the heating chamber 1 can be significantly changed. Uneven heating can be improved.
[0029]
In the first embodiment, the mover 17 is a column having a semicircular cross-sectional shape. However, as shown in FIG. 2, the vertical and horizontal lengths are the width of the waveguide 5 and the feed port, respectively. The same effect can be obtained even with a rectangular metal plate (which is bent into a square shape in the figure) that substantially matches the diameter. In the illustrated case, 18 is a mover, 19 and 19a are a motor for rotating the mover 18, and a shaft of the motor 19 to which the mover 18 is attached.
[0030]
Furthermore, although a flat surface made of a metal column or a metal plate is taken up as a movable wall for reflecting high frequencies, a surface made of a metal mesh may be used. In this case, in order to obtain a high reflectance, it is desirable that the mesh eye size, that is, the length of one side, is ¼ or less of the wavelength of the high frequency used.
[0031]
In addition, although the case where the waveguide 5 and the power feeding port are provided on the back plate of the heating chamber 1 has been described in the first embodiment, it may be provided on the side plate of the heating chamber 1. In this case, the same effect is obtained. In the first embodiment, the case where the movable wall rotates has been described. However, the present invention is not limited to this, and the same effect can be obtained by other movements.
[0032]
Embodiment 2. FIG.
FIG. 3 is a perspective view of a main part in the second embodiment of the present invention. Parts that are the same as or equivalent to those in the conventional example or the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0033]
In the figure, a circular power supply port 20 is provided at substantially the center of the bottom plate 1c of the heating chamber 1, and is guided so as to cover the power supply port 20 along the bottom plate 1c so as to guide the high frequency from the antenna 4 to the power supply port 20. A wave tube 5 is provided.
[0034]
The shape of the power supply port 20 is substantially the same as the shape of the mounting table, the mover is installed in close contact with the power supply port 20, and the flat surface of the mover is the movable wall of the waveguide, the same as in the first embodiment. It is.
In addition, since the operation until the object to be heated is set and the heating is started is the same as that of the first embodiment, the description is omitted.
[0035]
In this configuration, since the power feeding port is provided on the bottom plate and the shape of the power feeding port 20 is substantially coincident with the shape of the mounting table, the mounting table 6 can be obtained simply by rotating the mover 17 and shaking the high-frequency radiation direction. The upper object 7 can be heated uniformly. Thus, by rotating the mover 17, it is possible to satisfy the function of the rotary plate that rotates the article 7 to be heated. Therefore, the rotary plate, the motor for driving the rotary plate, the drive mechanism, and the like are not necessary, and it is possible to provide an inexpensive high-frequency heating apparatus with reduced number of parts and improved assembly workability.
[0036]
Furthermore, a detection unit that detects the heating state of the object 7 to be heated may be provided in the upper part of the heating chamber 1 to determine the finished state of the object 7 to be heated. By configuring in this way, uniform heating can be realized by detecting an underheated part and moving the mover 17 so that the high frequency is intensively applied to this part.
[0037]
Examples of such detection means include an infrared sensor, a vapor sensor, and a temperature sensor. Finely detect the finished state of each part of the object 7 to be heated by using a method such as combining one of these sensors with a scanning system, making an array, or combining different types of sensors. Is possible.
[0038]
In the present embodiment, the waveguide 5 and the power feeding port are provided on the bottom plate 1b of the heating chamber 1. However, the waveguide 5 and the power feeding port may be provided on the ceiling plate 1d of the heating chamber 1, and the power feeding port is provided on the bottom plate 1b. The same effect as the case can be expected.
[0039]
Embodiment 3 FIG.
FIG. 4 is a longitudinal sectional view of an essential part in Embodiment 3 of the present invention.
Parts that are the same as or equivalent to those in the conventional example or the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.
In the figure, reference numerals 6a and 6b denote mounting tables installed in the upper and lower stages of the heating chamber, and the objects to be heated 7a and 7b are placed on the mounting tables. Reference numerals 21a and 21b are detection means for detecting the finishes installed in the upper and lower stages of the heating chamber 1, respectively, and the heating status of the heated objects 7a and 7b in the heating chamber is monitored by these detection means. Reference numeral 22 denotes a power supply port.
[0040]
In such a configuration, consider a case where the upper and lower heated objects 7a and 7b are heated simultaneously.
After placing the objects to be heated 7a and 7b on the two placing tables 6a and 6b installed in the heating chamber 1, respectively, the door is closed, the cooking time is set from the operation panel, and cooking is started. The high frequency oscillator 3 is activated, and high frequency oscillates. This high frequency is radiated from the antenna 4 through the waveguide 5 whose shape has been changed by the mover 17 into the heating chamber 1 from the feeding port 22 to directly irradiate the objects 7a and 7b to be heated, and the wall surface of the heating chamber 1 And indirectly heat the heated objects 7a and 7b.
[0041]
Here, the finishing states of the objects to be heated placed on the upper and lower stages of the heating chamber 1 are simultaneously monitored by the detection means 21a and 21b for detecting the finish, respectively, and the object to be heated 6a placed on the upper stage and the lower stage The finished situation of the object 6b to be heated placed on is compared.
For this reason, for example, when the heated object 7b placed on the lower stage is insufficiently heated as compared with the heated object 7a placed on the upper stage, the mover 17 is rotated upward to move the waveguide 5 The path and the power feeding port are guided below the heating chamber 1, and a large amount of high frequency is irradiated to the heated object 7b placed below the heated object 7a placed on the upper stage to compensate for insufficient heating. And finishing of the heated objects 7a and 7b placed on the lower stage can be completed at the same time.
[0042]
As a result, the user takes out the first finish while looking at the heating conditions of the heated objects 7a and 7b placed on the upper and lower stages, and resets and starts the remaining cooking time. This work is eliminated and convenience is improved.
[0043]
Note that the operation is reversed when the heated object 7b placed on the upper stage is insufficiently heated as compared to the heated object 7a placed on the lower stage.
Further, although the finish detection means is provided in each stage, it may be configured to provide one place at an appropriate position in the heating chamber so as to check the finish status of each stage.
Moreover, although the case where the mounting table has two stages has been described, the same is true even when the number of stages is larger.
[0044]
【The invention's effect】
The high-frequency heating device according to the present invention is configured as described above and has the following effects.
[0045]
The part of the wall of the waveguide leading the sheet collector port formed in a rear plate wall of the heating chamber and movable wall is provided with drive means for rotating and moving this, to vary the waveguide feed port shape simultaneously Therefore, the high frequency can be efficiently introduced into the heating chamber, the standing wave distribution in the heating chamber can be changed significantly, the heating speed can be improved, and the heating unevenness can be reduced.
[0046]
Further, a single feeding port, the movable wall is a column that substantially matches the shape of the feeding port, and the height is a mover formed so as to substantially match the height of the cross section of the height of the waveguide, Since this mover is designed so that the flat side of the column functions as a movable wall of the waveguide, high-frequency waves can be efficiently introduced into the heating chamber, and the standing wave distribution in the heating chamber can be significantly changed. Thus, the heating speed can be improved and uneven heating can be reduced.
[0047]
Further, a plurality of mounting tables are arranged substantially in parallel with the bottom plate of the heating chamber, finish detection means for detecting the heating status of the object to be heated placed in each is provided in the heating chamber, based on the signal of the finish detection means, Since the movable means is appropriately rotated or moved by the driving means to control the irradiation of the high frequency to each heated object, it becomes possible to finish heating of the heated objects at the same time, and the high frequency that is highly convenient. A heating device is obtained.
[0048]
Furthermore, based on the information on the type and shape of the object to be heated, the movable wall is rotated and moved so that the high frequency is evenly irradiated to the object to be heated, so that the heating speed is reduced. It is possible to improve and reduce heating unevenness.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part in a first embodiment of a high-frequency heating device according to the present invention.
FIG. 2 is a perspective view showing another embodiment of the mover in the high-frequency heating device according to the present invention.
FIG. 3 is a perspective view of a main part in a second embodiment of the high-frequency heating device according to the present invention.
FIG. 4 is a longitudinal sectional view of a main part in a third embodiment of the high-frequency heating device according to the present invention.
FIG. 5 is a longitudinal sectional view of a main part in a conventional high-frequency heating device.
FIG. 6 is a longitudinal sectional view of a main part in another conventional high-frequency heating apparatus.
[Explanation of symbols]
1 heating chamber, 1a right side plate, 1b bottom plate, 1c left side plate, 1d ceiling plate,
1e Back plate, 1f, 2 feeding port, 3 high frequency oscillator, 4 antenna,
5 waveguide, 5a waveguide, 5b waveguide, 6 mounting table, 7 object to be heated,
8 Rotary plate, 9 Motor, 9a Shaft, 10 Power supply port,
11 feeding port, 12 switching means, 13 opening, 14 opening, 15 disc,
16 power supply port, 17 mover, 18 mover, 19 motor,
19a Motor rotating shaft, 20 power supply port, 21a Finishing detection means,
21b Finish detection means, 22 Power supply port

Claims (3)

A heating chamber that houses an object to be heated, a high-frequency oscillator, a waveguide that propagates high-frequency waves oscillated from the high-frequency oscillator into the heating chamber, and a boundary between the waveguide and the heating chamber on the back of the heating chamber A part of the wall surface of the waveguide connected to the power supply port is a movable wall, and driving means for rotating or moving the movable wall is provided so that the shape of the power supply port and the waveguide is While simultaneously changing, a detection means for detecting the heating state of the object to be heated is provided, and the driving means controls the high-frequency irradiation to the object to be heated based on a signal from the detection means, A single feeding port, the movable wall is a column that substantially matches the shape of the feeding port, and a mover that is formed so that its height substantially matches the height of the cross section of the height of the waveguide. The mover has a flat side of the column that High-frequency heating apparatus is characterized in that so as to function as Dokabe.   A plurality of mounting tables arranged substantially in parallel with the bottom plate of the heating chamber, and detection means for detecting the heating status of the object to be heated mounted on each mounting table are provided in the heating chamber, and the detection The high frequency heating apparatus according to claim 1, wherein the driving means rotates or moves the movable wall based on a signal from the means to control high frequency irradiation to each object to be heated.   Input means for inputting information on the type and shape of the object to be heated is provided, and the driving means controls the high-frequency irradiation to the object to be heated based on a signal from the input means. The high-frequency heating device according to claim 1 or 2.

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