JP4882427B2 - Microwave heating device - Google Patents

Description

The present invention relates to a microwave heating apparatus that heats an object to be heated with microwaves.

The microwave oven, which is a typical microwave heating device, can directly heat food, which is a typical object to be heated, and is an indispensable device in daily life with the simplicity that does not require the preparation of a pan or pot. ing. In addition, in order to uniformly heat food in a microwave oven, a turntable method in which the food itself is rotated was once the mainstream. I had to design it in a nearly square shape. However, in recent years, a product having a heating chamber shape with a wide width has been put into practical use so that it can be heated even if a plurality of tableware are arranged in order to improve convenience. This is called a rotating antenna system rather than a turntable, and it is configured to heat evenly by rotating an antenna that can change the direction of the microwave below the food without moving the food. Then, it is also considered to arrange a plurality of antennas (for example, see Patent Document 1).
JP 2004-259646 A

  However, the conventional configuration described above diversifies the change pattern of the electric field distribution by rotating each of the two rotating antennas having different rotational speeds. However, when placing large foods that span both rotating antennas, the center of the bottom of the food is heated by the microwaves from both antennas, so heating is fast, but the area around the bottom of the food is from either antenna. There was a tendency for only microwaves to reach and slow heating.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a microwave heating apparatus that can uniformly heat a large food with two rotating antennas.

In order to solve the conventional problems, a microwave heating apparatus of the present invention is connected to a microwave generation means, a waveguide for transmitting microwaves from the microwave generation means, and an upper portion of the waveguide. A heating chamber, a non-rotating mounting table disposed in the heating chamber for mounting the object to be heated, a heated object storage space formed above the mounting table in the heating chamber, An antenna space formed below the mounting table, two rotary antennas disposed from the waveguide to the antenna space for radiating microwaves in the waveguide into the heating chamber, and the two Drive means for rotationally driving the rotary antenna; and control means for controlling the direction of the two rotary antennas by controlling the drive means, wherein the control means is a radiation finger of the two rotary antennas. Has a first control pattern sex strong site is inversion driving so do not face each other, the second control pattern inversion driving as strong sites radiation directivity of the two rotation antennas face each other, wherein The first control pattern and the second control pattern are switched during heating .

  This can reduce the microwaves that are concentrated on the center of the bottom of a large food from both of the two rotating antennas, so that the heating of the center of the bottom of the food can be prevented from proceeding excessively, and heating can be performed more uniformly. it can.

  According to the microwave heating apparatus of the present invention, since the microwaves intensively irradiated to the center of the bottom of a large food from both of the two rotating antennas can be reduced, the heating of the center of the bottom of the food is prevented from proceeding excessively. Can be heated more uniformly.

According to a first aspect of the present invention, there is provided a microwave heating apparatus including: a microwave generation unit; a waveguide that transmits microwaves from the microwave generation unit; a heating chamber connected to an upper portion of the waveguide; A non-rotating mounting table disposed in the heating chamber, a heated object storage space formed above the mounting table in the heating chamber, and a lower position than the mounting table in the heating chamber. An antenna space, two rotating antennas disposed from the waveguide to the antenna space for radiating microwaves in the waveguide into the heating chamber, and driving means for rotationally driving the two rotating antennas And control means for controlling the direction of the two rotating antennas by controlling the driving means, wherein the control means is configured such that the parts having strong radiation directivity of the two rotating antennas face each other. It has a first control pattern that inversion driving so as not, the second control pattern inversion driving as strong sites radiation directivity of the two rotation antennas face each other, the said first control pattern The second control pattern is switched during heating . This reduces the microwaves that are intensively applied to the bottom center of the food so that the parts with strong radiation directivity of the two rotating antennas do not face each other, or the parts with strong radiation directivity of the two rotating antennas It is possible to increase the number of microwaves that are focused on the bottom center of the food so as to face each other, and to control the heating distribution according to the purpose. For example, the microwaves that are concentrated on the bottom center of the food It is possible to switch from a low to a high state, or from a high to a low state, and to control the heating distribution more precisely according to the purpose, and concentrate on the center of the bottom of the food from both two rotating antennas. Can reduce the amount of microwaves that are radiated, preventing excessive heating at the center of the bottom of the food and heating more evenly Door can be.

The microwave heating apparatus according to a second aspect of the invention further includes temperature detection means for detecting the temperature of the object to be heated , particularly in the first invention, and the control means first detects the object to be heated in the first control pattern. Heating is performed, and when it is determined that the temperature at the center of the object to be heated is lower than the surroundings by the detection of the temperature detecting means, the second control pattern is switched . Thereby, since the heating distribution can be changed according to the temperature of the object to be heated, the heating distribution can be controlled more accurately according to the purpose .

The microwave heating apparatus according to a third aspect of the invention further includes setting means set by a user, particularly in the first aspect, and the control means is configured to switch the control pattern according to the contents set by the setting means. . As a result, the heating distribution can be changed according to the set contents, so that the heating distribution control according to the purpose can be performed more accurately.

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

(Embodiment 1)
1 to 4 are configuration diagrams of a microwave oven that is a typical microwave heating apparatus according to the present invention. FIG. 1 is a cross-sectional view as viewed from above the rotary antenna, and FIG. 2 is a cross-sectional view as viewed from the right. 3 and 4 are cross-sectional views as seen from above.

This embodiment is a microwave oven using a rotating antenna system, and is generated from a magnetron 2 which is a typical microwave generating means for supplying microwaves from below the mounting table 1 on which food is placed. A waveguide 5 that guides microwaves into the heating chamber 3 through two coupling holes 4 provided on the bottom surface of the heating chamber 3, and is arranged on each coupling hole 4 and is rotatable about the coupling hole 4. The rotating shafts 6 and 7 are provided, and a driving shaft 9 of a motor 8 which is a typical driving means is connected to the rotating antenna 6.
, 7 can be fitted to the coupling shaft 10 and the rotating antennas 6 and 7 can be rotated to change the radiation direction of the microwaves.

  In particular, in the present embodiment, an example in which two rotating antennas 6 and 7 are arranged in the horizontal direction of the horizontally long heating chamber 3 has been shown. However, one magnetron 2 is provided, the waveguide 5 is branched in a T shape, and the rotating antennas 6 and 7 are symmetrically arranged on both sides.

  The rotating antennas 6 and 7 have bent portions 11 and 12 that are bent on two sides facing each other with the coupling shaft 10 and a bent portion 13 that is bent on the other side, and are open only on the tip 14 side that is not bent. By forming, microwaves with strong directivity can be emitted mainly to the tip 14 side. Therefore, it can be said that the tip 14 is a portion having a strong radiation directivity of the rotating antennas 6 and 7.

  Here, one motor 8 may be provided for each of the two rotating antennas 6 and 7, but a configuration in which the two rotating antennas 6 and 7 are simultaneously rotated by one motor 8 and a gear is also conceivable. The individually provided rotating antennas 6 and 7 can be combined in various directions, and the heating distribution can be changed variously.

  In any case, the heating distribution can be changed by changing the radiation direction of the microwave by appropriately controlling the rotation antennas 6 and 7 to be rotated or stopped in a specific direction. For this reason, the control means 15 controls the magnetron 2 based on the setting information from the setting means 16 for setting the menu and the heating time by the user, the information from the temperature detection means 17, and the like to generate and stop the microwave. Or the motor 8 is controlled to control the rotation and stop of the rotating antennas 6 and 7.

  The heating chamber 3 is considered to be composed of a heated object storage space 18 formed above the mounting table 1 and an antenna space 19 formed below the mounting table. A food 20 that is a typical object to be heated is placed on the mounting table 1 in the object storage space 18.

  Next, the control pattern will be described.

  In the present embodiment, the portion having strong radiation directivity of the rotating antennas 6 and 7 is on the tip 14 side, so first, for example, arrows 21 and 22 from the coupling axis 10 toward the tip 14 are considered as main directions of the microwaves.

  Then, when the directions of the rotating antennas 6 and 7 are expressed by an angle formed with the direction of the arrow line with reference to the right direction of FIG. 1, in the case of FIG. 1, the rotating antenna 6 is 180 degrees and the rotating antenna 7 is 0 degrees. It will be in. The rotating antenna 6 is controlled so as to reciprocate only between about 45 degrees and 315 degrees (the locus is a broken line 23). Specifically, the rotation direction of the motor is reversed at 45 degrees and 315 degrees. Take control.

  Similarly, the rotating antenna 7 is controlled so as to reciprocate only between approximately 225 degrees and 135 degrees (the locus is a broken line 24). Specifically, the rotation direction of the motor is reversed at 225 degrees and 135 degrees. To control.

  FIG. 3 and FIG. 4 show how the heating distribution in the case of the food 20 is changed so that the horizontal shape spans both rotating antennas.

FIG. 3 shows the part (heating part 25) where the temperature of the food 20 becomes high when the control as in the present embodiment is performed, and FIG. 4 continued to rotate without turning the rotating antennas 6 and 7 together. The part (heating part 26,27,28) where the temperature of the foodstuff 20 in the case becomes high was shown.

  If the rotation continues as shown in FIG. 4, the bottom of the food 20 is intensively heated when the rotating antenna 6 turns to the right (0 degree), and also when the rotating antenna 7 turns to the left (180 degrees). The bottom of the food 20 is heated intensively, and the temperature of the bottom is too high. That is, heating of the heating parts 26 and 27 proceeds faster than the heating part 28.

  Therefore, as in the present embodiment of FIG. 3, the heating to the bottom of the food 20 is weakened by inversion control so as not to cause the rotating antenna 6 to turn right or the rotating antenna 7 to turn left. Is possible.

  As described above, in the present embodiment, the two rotary antennas 6 and 7 are configured to be driven in an inverted manner so that the strong radiation directivity portions (tips 14) do not face each other.

This can reduce the microwaves intensively radiated from both of the two rotating antennas 6 and 7 to the bottom center of the food 20, so that heating at the bottom center of a large food, particularly across both rotating antennas, is reduced. It is possible to prevent excessive progress and to heat more uniformly. (Embodiment 2)
5 and 6 are configuration diagrams of the microwave oven, FIG. 5 is a cross-sectional view seen from above the rotating antenna, and FIG. 6 is a cross-sectional view seen from the right. In the present embodiment, the rotary antennas 29 and 30 are configured by an antenna having an opening 31 in a metal plate, and microwaves are easily transmitted to the opening 31 side. Therefore, the opening 31 can be considered as a portion having a strong radiation directivity. .

  In the present embodiment, although the configuration of the rotating antenna is different, if, for example, the arrows 32 and 33 facing the center of the opening 31 from the coupling axis 10 are considered as the main directions of the microwaves, as in the first embodiment, FIG. The direction of the rotating antennas 29 and 30 can be expressed by an angle formed with the direction of the arrow line with reference to the right direction of 5.

  For this reason, the same control as in the first embodiment can be performed, but here, it will be described that another control can be performed in addition thereto. Specifically, it is assumed that a drink such as milk is heated as the food 34. When the user selects milk with the setting means 16, milk is a food that easily causes convection, so if only the bottom is heated, the convection will naturally result in a uniform finish. Conversely, if microwaves are evenly irradiated, It is known that the temperature of the upper part becomes higher.

  Therefore, it is desirable to control so that the bottom part is heated intensively based on the setting contents of the setting means 16. Therefore, in this embodiment, in order to heat the bottom of the food 34 as much as possible, the rotating antenna 29 is controlled to reciprocate only between about 315 degrees and 45 degrees (the locus is a broken line 35). Control is performed to reverse the rotation direction of the motor at 315 degrees and 45 degrees.

  Similarly, the rotary antenna 30 is controlled so as to reciprocate only between about 135 degrees and 225 degrees (the locus is a broken line 36). Specifically, the rotation direction of the motor is reversed at 135 degrees and 225 degrees. To control. Thereby, the foodstuff 34 can heat a bottom part with the image like the heating site | part 37 of FIG.

  As described above, in the present embodiment, the first control pattern in which the openings 31 (parts having strong radiation directivities) of the two rotary antennas 29 and 30 are driven so as not to face each other and the second control pattern that is driven so as to face each other are reversed. The control pattern is configured as follows.

As a result, the microwaves intensively applied to the bottom center of the food 34 can be reduced so that the openings 31 (parts having strong radiation directivity) of the two rotating antennas 29 and 30 do not face each other, or the two rotating antennas can be reduced. It is possible to increase the number of microwaves intensively applied to the center of the bottom of the food 34 so that the openings 31 (strong radiation directivity portions) 29 and 30 face each other, or to control the heating distribution according to the purpose. .

  In addition, the setting unit 16 is set by the user, and the control unit 15 is configured to switch the control pattern according to the contents set by the setting unit 16.

  As a result, the heating distribution can be changed according to the set contents, so that the heating distribution control according to the purpose can be performed more accurately.

(Embodiment 3)
In the configuration of the first and second embodiments, another control is possible, and thus a description will be added. When it is possible to detect the temperature distribution of food using the temperature detection means 17 of FIGS. 2 and 6, the following control method can be considered. For example, at first, heating is started with a first control pattern that reversely drives so that parts with strong radiation directivity do not face each other as shown in FIG. 1, and as the heating proceeds, the temperature of the center of the food is detected by the temperature detection means 17. If it is determined that the temperature is lower than the surroundings, it is possible to perform a complex control such as switching to the second control pattern in which the portions having strong radiation directivity face each other in the middle of heating. If the rotating antenna is appropriately controlled according to the actual temperature distribution, a more uniform finish can be achieved.

  As described above, in the present embodiment, the control means 15 is configured to switch between the first control pattern and the second control pattern during heating.

  This makes it possible to switch from a state where there is a lot of microwaves intensively irradiated to the bottom center of food to a state where there is a lot of microwaves, or conversely, from a state where there is a lot of microwaves to a state where there are few microwaves. Can do.

  Moreover, it has the temperature detection means 17 which detects the temperature of a to-be-heated object, and the control means 15 is set as the structure which switches a control pattern with the temperature of the to-be-heated object which the temperature detection means 17 detected.

  Thereby, since the heating distribution can be changed according to the temperature of the object to be heated, the heating distribution can be controlled more accurately according to the purpose.

  In the above configuration, the first control pattern that reversely drives so that the parts with strong radiation directivity do not face each other and the second control pattern that performs reverse drive so that the parts with strong radiation directivity face each other will be described. Although an example in which the control pattern is switched only once in the middle has been shown, the present invention is not limited to this and may be switched any number of times.

  In addition, examples of angles at which the rotating antenna is inverted are 315 degrees and 45 degrees, and 135 degrees and 225 degrees, but the present invention is not limited to this. As a first control pattern, the meaning that the parts having strong radiation directivity do not face each other means that the first rotating antenna is controlled so as not to face the second rotating antenna, and the second rotating antenna is This means that the control pattern is such that control is performed so as not to face the rotating antenna.

It should be noted that the radiation directivity of the rotating antenna is easy to understand if the antenna has a simple shape as in this embodiment. However, in reality, there are various shapes such as a large number of apertures, asymmetrical with respect to the rotation axis, and it may be impossible to understand just by looking at where the radiation directivity is strong. Therefore, here, when a dielectric material such as food is laid on the mounting table 1 and heating is performed with only one rotating antenna being stopped, radiation is radiated in the direction in which the temperature rise of the dielectric material becomes maximum with respect to the rotation axis. Judge that there is directivity.

  As described above, according to the present invention, the object to be heated can be uniformly heated by switching the antenna position control pattern. Therefore, the microwave oven, the microwave oven, and various dielectrics as cooking utensils using microwaves can be used. It can be applied to heating and thawing devices, semiconductor devices using microwaves, heating devices in industrial fields such as drying devices, ceramics heating, sintering or biochemical reactions.

Sectional drawing which looked at the microwave heating apparatus of Embodiment 1 of this invention from the top Sectional view of the microwave heating device viewed from the right Sectional drawing which shows the case where the strong radiation directivity part of the rotating antenna in the same microwave heating device does not face each other Sectional drawing which shows the case where the rotating antenna in the microwave heating device is rotated Sectional drawing which looked at the microwave heating apparatus of Embodiment 2 of this invention from the top Sectional view of the microwave heating device viewed from the right

1 Mounting table 2 Magnetron (microwave generation means)
3 Heating chamber 5 Waveguide 6, 7, 29, 30 Rotating antenna 8 Driving means 14 Tip (part with strong radiation directivity)
DESCRIPTION OF SYMBOLS 15 Control means 16 Setting means 17 Temperature detection means 18 Heated object accommodation space 19 Antenna space 20, 34 Food (object to be heated)
31 Aperture (part with strong radiation directivity)

Claims (3)

Microwave generation means;
A waveguide for transmitting microwaves from the microwave generating means;
A heating chamber connected to the top of the waveguide;
A non-rotating mounting table disposed in the heating chamber for mounting an object to be heated;
A heated object storage space formed above the mounting table in the heating chamber;
An antenna space formed below the mounting table in the heating chamber;
Two rotating antennas disposed across the antenna space from the waveguide to radiate microwaves in the waveguide into the heating chamber;
Driving means for rotationally driving the two rotating antennas;
Control means for controlling the drive means to control the direction of the two rotating antennas,
The control means is configured such that the first control pattern for driving inversion so that the strong radiation directivity portions of the two rotary antennas do not face each other, and the strong radiation directivity portions of the two rotary antennas face each other. Having a second control pattern for inversion drive;
A microwave heating apparatus configured to switch between the first control pattern and the second control pattern during heating . A temperature detecting means for detecting the temperature of the object to be heated;
The control means first heats the object to be heated with the first control pattern, and switches to the second control pattern when it is determined that the temperature at the center of the object to be heated is lower than the surrounding by detection of the temperature detecting means. The microwave heating apparatus according to claim 1. It further has a setting means for the user to set,
Control means, a microwave heating device according to claim 1, wherein a configuration for switching a control pattern depending on the contents set by said setting means.

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