JP2017053533A - Heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating cooker that can be suppressed in unevenness in heating regardless of a size of a heated object.SOLUTION: In a heating cooker including a weight sensor 40 and a rotary antenna 5 or a rotary loading platform, a driving motor 6 for rotating and driving the rotary antenna or the rotary loading platform is a motor of which a rotating speed and a rotating direction can be freely controlled, and a rotary antenna angle and a rotary loading platform angle are substantially made to agree with each other in start of heating and termination of heating by rotating the rotary antenna or the rotary loading platform at a rotating speed according to a heating time determined from a detection value of the weight sensor, thus unevenness in heating can be suppressed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cooking device that heats food using a microwave oscillator.

  In a microwave oven, which is a typical conventional cooking device of this type, a magnetron is used as a microwave oscillator, the microwave generated by the magnetron is supplied into the heating chamber, and the microwave energy is absorbed by the food in the heating chamber. By heating the food. The microwave used in the microwave oven has a frequency of 915 MHz to 2450 MHz, a wavelength of about 12 to 33 cm, and is smaller than the size in the microwave oven, so that a standing wave is generated in the heating chamber of the microwave oven. When a standing wave is generated in the heating chamber, when food is placed in the heating chamber, there are portions with high and low electric field strength depending on the position of the food. Unevenness occurs.

  Therefore, in order to control the distribution of microwaves absorbed by the food, the food is placed on the mounting table and the food is rotated in the heating chamber, or the antenna that radiates microwaves is rotated and the stationary in the heating chamber. A method for rotationally controlling the wave distribution has been devised. In such a microwave oven, the standing wave distribution in the heating chamber can be changed by rotating the food itself to change the standing wave distribution in the heating chamber or by rotating the microwave radiated from the antenna at a constant speed. By changing, the microwave energy absorbed by the food is controlled so as not to become strong at a specific position.

  In microwave ovens, an infrared sensor for detecting the surface temperature of food and a weight sensor for detecting the weight of food are widely used as detection means for detecting the state of food. When using an infrared sensor, the heating time from the food temperature rise to the desired temperature is estimated, and when using a weight sensor, the heating time is estimated from the weight of the food. Is set.

  A method has also been proposed in which the state of the object to be heated is detected by a sensor, the rotation of the antenna is controlled in accordance with the state, and the microwave is concentrated on the object to be heated.

  In Patent Document 1, when the maximum output is set and the temperature detected by the temperature detecting means is equal to or lower than a predetermined temperature, the impedance is matched to the light load placed at a specific position, and the microwave is directly concentrated. A microwave heating device that controls the direction of the rotating antenna is described.

  Patent Document 2 includes a rotating antenna having a multi-emitting part that emits microwaves more than other parts, and a region where a heated object detected by temperature detecting means is disposed or a heated object having a low temperature. When there is a multi-emission part in the area where is placed, a cooking device that increases the amount of microwave energy absorbed by the object to be heated at a low temperature by controlling the amount of microwave power transmitted to the cooking chamber Is described.

  Patent Document 3 describes a heating cooker having a temperature measuring means, a weight detecting means, a rotating antenna, calculating position information, and controlling the rotation of the rotating antenna driving means.

JP 2007-227282 A JP 2013-53795 A JP 2004-28361 A

  However, in these prior art examples, when it is desired to suppress the unevenness of the object to be heated and to heat it, a specific method for suppressing the unevenness of heating can be achieved by always rotating the antenna and the mounting table at a constant speed. There was no description, and in practice it was difficult to suppress uneven heating.

  In order to suppress heating unevenness of the object to be heated, it is necessary to change the standing wave distribution in the heating chamber over time and make the average electric field strength distribution inside the food during the heating time uniform. By simply rotating the standing wave distribution in the room, it was not possible to relax the electric field strength distribution when the standing wave distributions were superimposed.

  Even if the state of the object to be heated is detected using various sensors, only the microwave output and the heating time are adjusted to reflect the detected value, and the rotation speed of the antenna is not controlled. And the antenna angle at the end of heating were almost the same. Therefore, even with a structure in which the electric field strength distribution is made closer to uniform by rotating the antenna once, the heating unevenness of the object to be heated cannot be reduced.

  In addition, in these examples of prior art documents, a method of concentrating microwaves on an object to be heated by controlling a standing wave by a rotating antenna is described. In order to do this, the antenna was always rotated at a constant speed, and uneven heating could not be suppressed.

Hereinafter, problems of the devices described in Patent Documents 1 and 2 will be described.
(1) The microwave utilization apparatus described in Patent Document 1 is a control method that performs stop, reciprocation, and rotational speed reduction control toward a portion of a rotating antenna where the microwave radiation directivity is strong. The intensity distribution cannot be made uniform. In addition, the control is performed only when the temperature of the food is lower than the predetermined temperature so that the unevenness of the heating does not occur. However, the structure of the food is not fed back and reflected in the control, and thus the unevenness of the heating occurs during the heating. was there.
Further, the microwave is directly irradiated only to a load arranged at a predetermined specific position, and the control effect is small for a load not arranged at the specific position.
(2) The heating cooker described in Patent Document 2 includes a temperature detection unit that detects a temperature difference between a plurality of objects to be heated. This is a structure that controls heating by changing the microwave output in the area where the heated object is placed, and it uses a detection value of the infrared sensor to reduce the temperature difference between multiple heated objects. Uneven heating of the heated product could not be suppressed.
(3) Although the heating cooker described in Patent Document 3 has a structure for controlling the rotation of the rotating antenna driving means from the temperature detecting means and the weight detecting means, there is no detailed description of the rotation control method, and uneven heating can be suppressed. The control method is not considered.

  In order to solve the above problems, a heating cooker according to the present invention includes a heating chamber for storing food, a microwave oscillator for generating microwaves, weight detection means for detecting the weight of an object to be heated, A rotatable rotating antenna for controlling the microwave distribution and a driving motor for driving the rotating antenna are provided, and the driving motor is a motor that can be controlled by rotating speed, rotating direction, rotating angle, or a combination thereof. It is characterized by that.

  According to the present invention, the heating time is set in accordance with the weight of the object to be heated, and the rotation speed of the rotating antenna is adjusted according to the heating time so that the average electric field strength in the heating chamber is made close to uniform. Regardless of the size, heating with reduced heating unevenness is possible.

It is sectional drawing which looked at the heating cooker main body of Example 1 from the front side. It is the disassembled perspective view which looked at the heating cooker of FIG. 1 from the front upper side. It is the fragmentary sectional view which expanded the microwave transmission path structure of the cooking-by-heating machine of Drawing 1. It is a top view of the heating chamber bottom face of the heating cooker of FIG. FIG. 5 is a top view of the bottom surface of the heating chamber when the rotating antenna is rotated 90 degrees to the right from the top view shown in FIG. 4. FIG. 5 is a schematic diagram showing a region where the average electric field strength distribution is high when the rotating antenna is rotated once in the top view shown in FIG. 4. It is an algorithm in the case of cooking food by using the heating cooker of FIG. It is sectional drawing which looked at the heating cooker main body of Example 2 from the front side. It is sectional drawing which looked at the heating cooker main body of Example 3 from the front side. It is sectional drawing which looked at the heating cooker main body of Example 4 from the front.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The structure of the first embodiment will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view of the cooking device of the first embodiment when viewed from the front side. FIG. 2 is an exploded perspective view of the cooking device and the front upper side. FIG. 3 is an enlarged partial cross-sectional view of the microwave transmission path structure of the cooking device shown in FIG. FIG. 4 is a top view of the bottom surface of the heating chamber 3 of the heating cooker as viewed from above.

  The cooking device of the present embodiment is a turntableless single-function microwave oven (hereinafter referred to as a microwave oven) that has a range heating function for heating food using microwaves and does not have a mounting table for rotating food. However, the present invention is also applicable to a microwave oven having an oven heating function using a heater. Moreover, although the heating cooker of a present Example is equipped with the magnetron as a microwave oscillator, this invention is applicable also to the microwave oven provided with the microwave oscillator comprised by the semiconductor element.

[overall structure]
First, the structure of the main body 1 of the microwave oven (heating cooker) will be described. As shown in FIG. 1 and FIG. 2, the microwave oven main body 1 includes a heating chamber 3 that opens forward, a door 2 that can be opened and closed at the opening of the heating chamber 3, and a machine chamber 4 below the heating chamber 3. I have. The door 2 can be opened and closed by rotating in the vertical direction. Further, the main body 1 of the microwave oven is configured by covering the heating chamber 3 and the machine room 4 with a cabinet 10.

  Three weight sensors 40 are installed on the bottom surface of the heating chamber 3, and a table plate 31 that is a mounting table on which food is placed is placed on the weight sensor 40. That is, the total weight of the object to be heated placed on the table plate 31 can be measured by the three weight sensors 40. Further, since three weight sensors 40 are arranged, it is possible to detect the position of the center of gravity of the heated object, that is, the arrangement position of the heated object, from the ratio of the detection values of the weight sensor 40.

  An infrared sensor 41 is installed on the upper surface of the heating chamber 3. The surface temperature of the heated object placed on the table plate 31 can be detected by the infrared sensor 41.

  Here, if the infrared sensor 41 has a plurality of detection elements or a sensor having a driving means (not shown) capable of scanning the temperature detection position, the temperature at a plurality of positions on the table plate 31 is detected. , It is possible to detect the surface temperature for each position. In addition, since the area for detecting the temperature is small, the temperature of the object to be heated having a smaller surface area can be measured. Therefore, by using this, the shape of the food viewed from the position of the infrared sensor 41 and the temperature of each part can be measured and grasped. The detection accuracy of the food shape and temperature differs depending on the number of detection elements and the driving method. For example, in the case of a structure in which an eight-element sensor is driven and the temperature is detected by dividing the sensor into 15 in the scanning direction of the sensor, X15 = 120 temperature detection is possible.

  As shown in FIGS. 3 and 4, the antenna housing 30 and the rotating antenna 5 are disposed inside the heating chamber 3 below the table plate 31, and the waveguide 8 is provided in the antenna housing 30. A magnetron 7 is connected via The microwave generated in the magnetron 7 is irradiated from the rotating antenna 5 toward the heating chamber 3 through the waveguide 8.

  The table plate 31 is made of a material that absorbs a small amount of microwaves, such as ceramic and glass, and is easy to transmit. When a heated object such as food is placed on the table plate 31, irradiation is performed from the rotary antenna 5. Then, the object to be heated can be heated by the microwave transmitted through the table plate 31. Further, since the table plate 31 has substantially the same shape as the bottom surface of the heating chamber 3, the volume of the heating chamber 3 can be used as widely as possible.

  When cooking food, the food is first placed on the table plate 31, the door 2 is closed, and cooking is instructed on an operation panel (not shown). The microwave output from the magnetron 7 according to the set heating method is supplied to the waveguide 8 and transmitted to the rotating antenna 5 inside the antenna housing 30. The microwave transmitted to the rotating antenna 5 passes through the table plate 31 and is radiated into the heating chamber 3, absorbed by the food placed on the table plate 31, and converted into heat energy, thereby changing the temperature of the food. Rises. The food is cooked as described above.

[Microwave transmission path configuration]
Next, the detailed structure of the microwave transmission path will be described. As shown in FIGS. 3 and 4, a table plate 31 placed on three weight sensors 40 is disposed on the bottom surface of the heating chamber 3, and an antenna storage unit 30 is disposed below the table plate 31. A waveguide 8 is connected below the antenna housing 30, and the rotating antenna 5 is disposed inside the antenna housing 30. A waveguide opening 80 that is an opening is provided between the waveguide 5 and the antenna housing 30, and the antenna shaft 51 passes through the waveguide opening 80 and the lower wall surface of the waveguide 8. A stepping motor 6 is provided outside, and a motor shaft 61 is provided inside the waveguide 8.

  The rotating antenna 5 and the antenna shaft 51 are each made of a metal material and are electrically connected to each other. The motor shaft 61 is made of a non-metallic material such as resin, and the rotating antenna 5 and the antenna shaft 51 are not electrically connected to the wall surface of the waveguide 8. Therefore, the antenna shaft 51 and the waveguide opening 80 constitute a coaxial transmission line, and the microwaves directly flow through the antenna shaft 51 and the rotating antenna 5, so that the microwave inside the waveguide 8 is transferred to the antenna housing portion. 30. The microwave transmitted to the antenna storage unit 30 is radiated upward from the rotating antenna 5, passes through the table plate 31, and is supplied into the heating chamber 3.

  The motor shaft 61 and the antenna shaft 51 are connected so as to be able to be interlocked. When the stepping motor 6 is driven to rotate, the motor shaft 61 and the antenna shaft 51 and the rotating antenna 5 connected thereto rotate. Therefore, the rotating antenna 5 can be rotated by rotating the stepping motor 6.

  In this embodiment, the motor for driving the rotating antenna 5 is the stepping motor 6 capable of controlling the rotational speed and the rotational direction, but the type of the motor is not limited as long as the rotational speed and the rotational direction can be controlled. For example, in the case of a DC motor, the rotational speed can be controlled by driving with a control circuit that can change the input voltage or phase control, and in the case of an AC motor, the rotational speed can be controlled by driving with a control circuit that can change the input frequency. It can be adjusted. Further, the stepping motor 6 can detect the current angular position of the rotating antenna 5 by itself. However, by providing a sensor and a switch for detecting the rotating angle, the DC motor and the AC motor can also detect the rotating antenna 5. The angular position can be detected.

  Here, if the rotating antenna 5 has a highly directional antenna shape that radiates microwaves in a specific direction, the standing wave distribution inside the heating chamber 3 can be controlled by the rotation angle of the rotating antenna 5. That is, it is possible to move in a high electric field strength region where electric field strength is high. For example, in the direction of the rotating antenna 5 shown in FIG. 4, a standing wave having a high electric field strength on the back side of the heating chamber 3 (upward direction in FIG. 4) is generated as shown by a high electric field strength region 32 in FIG. To do. The position of the high electric field strength region 32 can be moved by changing the angle of the rotating antenna 5.

[Control method]
A method for controlling the rotating antenna 5 will be described with reference to FIGS. 5 is a top view when the rotating antenna 5 is rotated 90 degrees to the right from the state of FIG. 4, and FIG. 6 is a schematic diagram showing a region where the average electric field strength distribution is high when the rotating antenna is rotated once. is there.

  As shown in FIG. 5, when the rotating antenna 5 is rotated 90 degrees to the right from the state of FIG. 4, a standing wave with high electric field strength is generated on the right side of the heating chamber 3 (right direction in FIG. 4). The region 32 rotates. Similarly, when the rotating antenna 5 is rotated 180 degrees from the state of FIG. 4, the heating chamber 3 front side (downward in FIG. 4), and when the rotating antenna 5 is rotated 270 degrees, the left side of the heating chamber 3 (leftward in FIG. 4). Thus, the electric field strength can be increased. Therefore, by changing the angle of the rotating antenna 5, it is possible to generate a standing wave distribution with high electric field strength at an arbitrary position in the heating chamber 3. Therefore, when it is desired to heat a part of the object to be heated, it is possible to heat the specific direction in a concentrated manner by adjusting the rotation angle of the rotating antenna 5 and increasing the electric field strength in the specific direction.

  In addition, when the rotating antenna 5 is rotated once, the high electric field strength region goes around the inside of the heating chamber 3. Therefore, when the microwave output is constant, the standing wave distribution inside the heating chamber 3 is averaged over the heating time. The electric field strength distribution can be made uniform. As shown in FIG. 6, when the rotating antenna 5 is rotated once, the region 33 with a high average electric field strength is located widely without being biased in a specific direction around the heating chamber 3, and the rotating antenna 5 is specified. Compared with the case where it is directed in the direction, it is possible to perform heating while suppressing uneven heating of the object to be heated.

  In the heating cooker of this structure, since the rotating antenna 5 is driven by the stepping motor 6, the rotating antenna 5 rotates by an integral multiple of the heating time, that is, the antenna angle at the start of heating and the antenna at the end of heating. By making the angles substantially the same, the average electric field strength distribution can be made nearly uniform, and uneven heating can be suppressed. On the other hand, for example, when the rotating antenna 5 is rotated 1.5 times, the high electric field strength region 32 moves by an additional 0.5 rotations in addition to the case of one rotation. Becomes stronger than other positions and causes uneven heating. However, in the present invention, the rotation unevenness inside the heating chamber 3 can be alleviated by rotating the rotating antenna 5 by an integral multiple during the heating time.

  Here, since the heating time varies depending on the type and size of the object to be heated, in the conventional rotating antenna 5 that rotates at a constant speed, the number of rotations during the heating time of the rotating antenna 5 does not become an integral multiple, so heating unevenness occurs. It sometimes occurred. For example, when the rotation speed is constant at 10 seconds per rotation (0.2π rad / s), the rotation time is 10 rotations when the heating time is 100 seconds, but 10.5 rotations when the heating time is 105 seconds. Then, the angle at the start of heating of the rotating antenna 5 differs from the angle at the end of heating by 180 degrees (π rad) for 0.5 rotation, and heating unevenness is likely to occur.

  In the cooking device of the present embodiment, since the driving motor of the rotating antenna 5 is the stepping motor 6 and the rotation speed can be controlled, the rotation speed can be freely changed according to the heating time. The heating unevenness can be suppressed by controlling the rotation speed so that the angle at the start of heating of the rotating antenna 5 and the angle at the end of heating substantially coincide. For example, when the heating time is 105 seconds and the rotation speed of the rotating antenna 5 is set to 10.5 seconds per rotation (0.19π rad / s), the heating is completed at 10 rotations. In addition, when the heating time is 200 seconds, the rotation speed is set to 20 seconds (0.1πrad / s) per revolution, and when the heating time is 50 seconds, the rotation speed is set to 5 seconds (0.35πrad / s) per revolution. Even if the heating time changes, the number of rotations of the rotating antenna 5 per heating can be made uniform so that the antenna rotation angle at the start of heating and the antenna rotation angle at the end of heating can be made substantially coincident.

  In addition, when the microwave output is not constant but changes in the middle, the electric field strength distribution in the oven can be made uniform by setting the number of rotations of the rotating antenna 5 to an integer for a constant output time. it can. For example, if the microwave output is heated at 800W for 60 seconds, followed by heating at 600W for 45 seconds, for a total of 105 seconds, the output is 800W in one round for 10 seconds (0.2πrad / s) and the output is 600W. By adjusting the rotation speed to 9 seconds (0.22π rad / s) per cycle, the number of rotations of the rotating antenna 5 can be made an integer for each output time zone.

  In addition, in a conventional cooking device that uses only an infrared sensor to measure the surface temperature of food and cooks it, the heating time is determined by detecting the rising speed of the surface temperature. I can't decide. Therefore, it was difficult to adjust the heating time according to the rotation angle. In the heating cooker of the present embodiment, the heating time is determined at the start of heating using the weight sensor 40. Therefore, the rotation speed can be easily adjusted in accordance with the heating time as compared with the heating cooker having only the infrared sensor. It is.

  Further, in this embodiment, both the weight sensor 40 and the infrared sensor 41 are provided, and the heating time is estimated more accurately at the start of heating to set the rotation speed of the antenna, and the temperature of the object to be heated during heating is set. It is possible to adjust the heating time and rotation speed by detecting the fluctuation, and it is possible to perform heating more suitable for the condition of the object to be heated. For example, if the heating time is set only by the weight sensor 40, the heating time may be too long when the object to be heated is contained in a container heavier than expected. Conversely, if the object to be heated is in a light container, the heating time may be too short. By detecting and correcting the surface temperature of the food in the middle of heating with the infrared sensor 41, the heating time can be adjusted appropriately. Further, by adjusting the rotation speed of the rotating antenna 5 according to the adjusted heating time, heating with reduced heating unevenness is possible.

  Further, in this embodiment, by controlling the rotation direction of the rotating antenna 5 by the stepping motor 6, it is possible to centrally heat the object to be heated at a specific position and to reduce heating unevenness. For example, when the surface temperature of the object to be heated is detected by the infrared sensor 41 and the temperature of a specific part of the object to be heated is low and intensive heating is required, the current position of the rotating antenna 5 is grasped by the stepping motor 6 and appropriate By switching the rotation angle and the appropriate rotation direction up to that angle by the stepping motor 6, heating unevenness can be alleviated.

  Further, when a plurality of objects to be heated are arranged on the table plate 31, the weight sensor 40 and the infrared sensor 41 can detect the position at which the objects to be heated and the weight distribution can be detected. Heating unevenness can be suppressed by adjusting the rotation speed and direction of the antenna 5 and the output of the microwave.

  For example, when a heated object that is heavy (frozen) and a light object that is light (refrigerated) are placed on the table plate 31 at the same time, weight distribution is performed based on the surface temperature of the object to be heated, the position of placement, and the center of gravity. Can be estimated. A heavy object to be heated in a frozen product is less likely to be heated than a light object to be heated in a refrigerated product. Therefore, the standing wave in the heating chamber 3 is adjusted so that the electric field strength distribution is higher in a heavy product to be heated in a frozen product. By controlling, it is possible to suppress uneven heating. For example, in the vicinity of the rotation angle of the rotating antenna 5 that is a more desirable standing wave distribution, the rotation speed is reduced compared to other rotation angles, or the rotation antenna 5 is rotated by switching the rotation direction. By controlling the direction of rotation, it is possible to control the standing wave distribution and suppress uneven heating.

  Therefore, in this embodiment, in the cooking device provided with the weight sensor 40, the infrared sensor 41, and the rotating antenna 5 having the above-described structure, the rotational motor and the rotating direction of the driving motor of the rotating antenna 5 are the same as the stepping motor 6. Is a motor that can be freely controlled, and heating unevenness can be suppressed by rotating the rotating antenna 5 at a rotation speed corresponding to the heating time.

[Heating method]
The control method in the case of actually heating food with the heating cooker using the structure of a present Example is demonstrated using FIG. FIG. 7 shows a control algorithm of this embodiment.

  First, food is placed on the table plate 31, the door 2 is closed, and automatic heating cooking (automatic cooking) is instructed. When cooking is instructed, the cooking device determines the weight, type, and shape of the food by the weight sensor 40 and the infrared sensor 41. For example, the weight sensor 40 can detect the weight of the food. Further, since the surface temperature of the food can be detected by the infrared sensor 41, the state of the food (whether it is frozen or refrigerated) can be determined. In addition, since the planar area of the food can be detected, the height of the food can be estimated together with the weight of the food.

  Here, when it is detected by the weight sensor 40 and / or the infrared sensor 41 that there is no food on the table plate 31, the heating is terminated. By terminating the heating when there is no food in the heating chamber 3, damage to the magnetron 7 due to the input energy returning to the magnetron 7 can be prevented.

  When the weight of the food and the initial temperature can be detected, the output of the magnetron and the heating time are set according to the weight of the food and the instructed heating type, and heating is started by driving the magnetron 7 with the set output. Microwaves oscillated by the magnetron 7 are transmitted to the antenna housing 30 via the waveguide 8 and irradiated from the rotary antenna 5 toward the heating chamber 3. The microwaves irradiated from the rotating antenna 5 pass through the table plate 31 and are absorbed by the food placed on the table plate 31.

  Here, the antenna rotation speed is set according to the detection value of the weight sensor and the infrared sensor and the heating time set according to the specified heating type. is there. First, the stepping motor 6 detects the angle of the rotating antenna 5 at the start of heating, and performs heating while rotating the rotating antenna 5 by the stepping motor 6 simultaneously with the start of heating, but at an appropriate rotation speed according to the heating time. The rotational speed of the stepping motor 6 is adjusted. By controlling in this way, the angle of the rotating antenna 5 at the start of heating and at the end of heating can be made substantially the same, the electric field strength distribution in the oven can be made to be uniform, and heating unevenness can be suppressed.

  It is also possible to adjust the rotational speed of the rotating antenna 5 depending on the type of food. When the heating time is 100 seconds, the rotation antenna 5 rotates 10 times during the heating time when the rotation time is set to 10 seconds. However, when the rotation speed of the rotation antenna 5 is set to 5 seconds per rotation, the rotation antenna 5 is rotated during the heating time. Rotates 20 times. In both cases, the rotation angle of the rotating antenna 5 at the start of heating and the rotation angle at the end of heating are substantially the same, and heating that suppresses uneven heating is possible, so an appropriate rotation speed and rotation speed should be selected depending on the food. Can do. For example, when heating a refrigerated food that is relatively easy to heat, a low rotation speed of 10 seconds is selected, and when heating a frozen food that is difficult to heat, a high rotation speed of one rotation is selected. It is also possible to select 5 seconds. Here, the difference between refrigeration and freezing is shown as an example. However, if the finish of the food differs depending on the rotation speed, the rotation speed is appropriate for the food and the number of rotations during the heating time is an integral multiple. Thus, it is possible to arbitrarily adjust the rotation speed of the rotating antenna.

  Further, when both the weight sensor 40 and the infrared sensor 41 are provided as in the present embodiment, the height of the food can be estimated from the detection values of both sensors. It is also possible to adjust the rotation speed appropriately. When the plane area of food is small and the height is relatively high, it is possible to adjust the microwave distribution so that, for example, liquid in a cup is assumed and temperature unevenness is unlikely to occur on the top and bottom of the food . Conversely, if the plane area of the food is large and the height is relatively low, unevenness in the plane of the food can be suppressed by adjusting the microwave distribution assuming a solid food such as a side dish in a flat plate. . In this way, the finished state of the food can be improved also by changing the rotation speed of the rotating antenna 5 depending on the type of food. For example, when a liquid object to be heated is assumed, the liquid moves in the container by convection and heating unevenness is unlikely to occur. Therefore, the rotating antenna 5 is heated at a low rotation speed, and the object to be heated is solid. In this case, it is possible to control that the heating unevenness is further reduced by heating the rotating antenna 5 at a high rotational speed.

  It is also possible to adjust the heating time by measuring the surface temperature of the food during heating. When the heating time is adjusted, the rotational speed of the rotating antenna 5 can be finely adjusted according to the new heating time. Since the antenna angle at the start of heating is detected by the stepping motor 6, it is possible to perform heating so that the heating is completed at the antenna angle at the start of heating by adjusting the rotation speed with respect to increase / decrease of the heating time. .

  By adopting the heating method as described above, the rotation angle of the rotating antenna 5 at the end of heating becomes substantially the same as that at the start of heating, and heating while suppressing heating unevenness is possible.

  In the present embodiment, the structure in which the infrared sensor 41 is mounted is shown, but even if the infrared sensor is not mounted, if the weight sensor 40 is provided as described above, the weight of the food is detected and the heating time is set. Therefore, it is possible to perform heating while suppressing heating unevenness by changing the rotation speed of the stepping motor 6 according to the set heating time. Therefore, in order to obtain the effect of this embodiment, the minimum configuration is the weight sensor 40 shown in this embodiment, the rotating antenna 5 that radiates microwaves, and the stepping motor 6 that drives the weight sensor 40. If there is a weight detecting means such as 40, a rotating antenna 5 having directivity in a specific direction, and a motor capable of controlling the rotational speed such as a stepping motor 6, heating with little heating unevenness is possible.

  Example 2 will be described with reference to FIG. FIG. 8 is a cross-sectional view of the main body of the heating cooker according to the second embodiment when viewed from the front side. The cooking device of the present embodiment has a structure different from that of the first embodiment in that the electric field strength sensor 42 is mounted on the left and right wall surfaces of the heating chamber 3 and the lower surface of the waveguide 8 and the infrared sensor is not mounted. It is.

  Since the electric field intensity inside the heating chamber 3 can be measured by the electric field intensity sensor 42, the fluctuation of the standing wave distribution when the rotating antenna 5 is rotated, that is, the change of the electric field intensity distribution at the sensor installation position is detected. By directly measuring, the electric field strength distribution around the food can be estimated. Therefore, even when the shape and physical properties of the food change, the standing wave distribution inside the heating chamber 3 can be grasped more accurately. Therefore, by controlling the rotating antenna 5 by the stepping motor 6 according to the electric field strength distribution around the food estimated from the electric field strength distribution detected by the electric field strength sensor 42, the average electric field strength distribution in the heating chamber is made more uniform. , Uneven heating can be reduced.

  Further, by combining the electric field strength sensor 42 and the weight sensor 40, it is possible to estimate physical properties such as whether or not the food easily absorbs microwaves. Therefore, as in the first embodiment, it is possible to obtain better heating performance by adjusting the rotation speed of the rotating antenna 5 according to the state of food.

  The structure of Example 3 will be described with reference to FIG. FIG. 9: is sectional drawing which looked at the heating cooker of Example 3 from the front side. As shown in FIG. 9, the microwave oven main body 1 of this embodiment has a circular shape in which a magnetron 7 and a waveguide 8 are placed on the right side of the heating chamber 3, and a rotary mounting table 52 is placed on the bottom of the heating chamber 3. A table plate 31 is provided. The rotary mounting table 52 is connected to the weight sensor 40 via the rotary shaft 53, and the weight sensor 40 can detect the weight of the object to be heated arranged on the table plate 31. The rotary shaft 53 of the rotary mounting table 52 is connected to the motor shaft 61 of the stepping motor 6 through a gear. By driving the stepping motor 6, the rotary mounting table 52 and the table plate 31, The object to be heated placed on can be rotated.

  In this embodiment, the standing wave in the heating chamber 3 is not changed by rotating the rotating antenna, but the standing wave in the heating chamber 3 is changed by rotating the object to be heated. This is different from the structure of the first embodiment in that the electric field strength distribution in FIG. The effect is the same as that of the first embodiment. The heating time is set based on the weight detected by the weight sensor 40, and the heating is started by setting the rotational speed of the stepping motor 6 according to the heating time. It is possible to perform heating while making the angle of the rotary mounting table 52 and the table plate 31 substantially coincide with each other at the end of heating and suppressing heating unevenness of the heated object.

  As in the other embodiments, the stepping motor 6 may be any motor as long as it can control the rotational speed and direction. Further, if other sensors such as an infrared sensor and an electric field strength sensor are installed, it is possible to further improve the heating by grasping the situation of the object to be heated and adjusting the heating time and the rotation speed of the rotary mounting table 52 accordingly. Is possible.

  The structure of Example 4 will be described with reference to FIG. FIG. 10 is a cross-sectional view of the cooking device of Example 4 as viewed from the front side. As shown in FIG. 10, the waveguide 8 of the present embodiment is provided with a microwave oscillation module 71 composed of a semiconductor element as a microwave oscillator.

  The microwave oscillation module 71 composed of a semiconductor element has a narrower oscillation frequency than that of the magnetron, and can adjust the frequency and phase of the oscillating microwave. Since the microwave oscillated by the microwave oscillation module 71 has a narrow oscillation frequency, a standing wave sharper than that of the magnetron is generated, and heating unevenness is likely to occur.

  However, in the structure of the present embodiment, the rotating antenna 5 that irradiates the microwave to the heating chamber 3 is rotated, and the frequency and phase of the microwave oscillation module 71 are adjusted, so that a stationary wave generated in the heating chamber 3 is generated. The wave state can be varied. In this embodiment, since the stepping motor 6 that drives the rotating antenna 5 is provided, the rotational speed and direction of the rotating antenna 5 can be arbitrarily controlled. Therefore, similarly to the first embodiment, it is possible to perform heating while suppressing heating unevenness of the object to be heated.

  Here, in the present embodiment, there is one microwave oscillation module 71, but a plurality of microwave oscillation modules 71 may be connected to the waveguide 8. By using the plurality of microwave oscillation modules 71, the microwave output supplied into the heating chamber 3 can be increased, and the object to be heated can be heated in a shorter time. Also in this case, by controlling the phase and frequency of the microwave oscillated from the microwave oscillating module 71 and controlling the rotation of the rotating antenna 5, it is possible to perform heating while suppressing heating unevenness.

  Further, since the microwave oscillation module 71 is weaker than the conventional magnetron with respect to the reflected wave, the microwave oscillation module 71 may be damaged if the heating chamber 3 is heated without any object to be heated. By determining the presence or absence of an object to be heated using the weight sensor 40, damage to the microwave oscillation module 71 can also be prevented. As described in the first and second embodiments, an infrared sensor or an electric field strength sensor may be installed in addition to the weight sensor 40.

1: Main body 10: Cabinet 2: Door 3: Heating chamber 30: Antenna storage unit 31: Table plate 32: High electric field strength region 33: High electric field strength region 4: Machine room 40: Weight sensor 41: Infrared sensor 410: Infrared sensor detection area 42: Electric field intensity sensor 5: Rotating antenna 51: Antenna shaft 52: Rotation mounting table 53: Rotating shaft 6: Stepping motor 61: Motor shaft 7: Magnetron 71: Microwave oscillation module 8: Waveguide 80: Waveguide opening

Claims (5)

A heating chamber for storing food,
A microwave generator for generating microwaves;
Weight detection means for detecting the weight of the object to be heated;
A rotatable rotating antenna that controls the microwave distribution in the heating chamber;
A drive motor for driving the rotating antenna;
The cooking device according to claim 1, wherein the drive motor is a motor that can be controlled by a rotation speed, a rotation direction, a rotation angle, or a combination thereof. A heating chamber for storing food,
A microwave generator for generating microwaves;
Weight detection means for detecting the weight of the object to be heated;
A rotary mounting table on which an object to be heated is rotated;
A drive motor for driving the rotary mounting table;
The heating cooker characterized in that the drive motor is a motor that can be controlled by a rotation speed, a rotation direction, a rotation angle, or a combination thereof.   The cooking device according to claim 1 or 2, further comprising temperature detection means for detecting the temperature of the object to be heated.   The cooking device according to any one of claims 1 to 3, further comprising an electric field strength measuring unit capable of measuring electric field strength and reflected waves in the heating chamber or a waveguide between the microwave oscillator and the heating chamber.   The cooking device according to any one of claims 1 to 4, wherein the driving motor is a stepping motor.

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