JP7818331B2 - Cooking device, method for controlling cooking device, and control program - Google Patents

Description

The present invention relates to a cooking device, a control method for a cooking device, and a control program.

A cooking appliance is required to heat food evenly to a target temperature in a short time.
Patent Document 1 discloses a high-frequency heating device that stops the antenna so that it maintains a predetermined initial antenna angle for a certain period of time after heating begins, in order to eliminate uneven heating, and then rotates the antenna after the certain period of time has passed based on information about the temperature rise rate of the heating chamber that has been obtained in advance.
Patent document 2 discloses a device that predefines the placement of the food items to eliminate uneven heating of two foods, measures the operating efficiency using anode current and voltage, and alternately concentrates heating on low-temperature and high-temperature areas.

Japanese Patent Application Laid-Open No. 2008-190752 JP 2012-174470 A

In Patent Document 1, information on the temperature rise rate of the heating chamber is used, but this is under no load and there is a problem that it does not take into account what happens when food is actually placed in the heating chamber. For example, even with the same antenna rotation angle, the temperature distribution changes depending on the type and placement of the food.
In Patent Document 2, the anode current and voltage are used to determine the temperature efficiency, but when two items are very close to each other, they cannot be distinguished from each other, which poses the problem of having to set them in advance.

The objective of this invention is to automatically set the antenna to an optimal angle so that food can be heated to the target temperature in a short amount of time depending on the type of food and its placement.

In order to solve the above-mentioned problems, the heating cooker of the present invention is characterized by comprising a heating chamber that contains food, an antenna that is arranged to rotate freely and that emits microwaves to heat the food, a motor that rotates the antenna, temperature detection means that can detect the temperature of the food contained in the heating chamber by distinguishing between at least two regions of the food, and control means that, while the food is contained in the heating chamber, the antenna that emits microwaves is rotated by the motor, the temperature detection means is used to detect the temperature of the region and calculate a temperature rise rate of the region, and after correlating the temperature rise rate of the region with the angle of the antenna, a first process is performed in which the antenna is rotated by the motor to an angle at which the temperature rise rate of the region is higher than a predetermined value and then stopped, followed by a second process in which the food is heated for a predetermined time , and the first process and the second process are repeated.

The control method for a cooking device of the present invention is a control method for a cooking device comprising a heating chamber that accommodates food, an antenna that is rotatably arranged and that emits microwaves to heat the food, a motor that rotates the antenna, a temperature detection means, and a control means, wherein the control means comprises the steps of: using the temperature detection means to distinguish between at least two regions of the food accommodated in the heating chamber and detect the temperature of the food; using the temperature detection means to detect the temperature of the region while rotating the antenna that emits microwaves with the motor while the food is accommodated in the heating chamber; calculating a temperature rise rate of the region based on a change in temperature of the region over time; correlating the temperature rise rate of the region with the angle of the antenna; a first step of rotating the antenna with the motor to an angle at which the temperature rise rate of the region becomes higher than a predetermined value and then stopping the antenna; and a second step of heating the food for a predetermined time after the first step , and repeating the execution of the first step and the second step .

The control program of the present invention causes the control means of a cooking device comprising a heating chamber that accommodates food, an antenna that is rotatably arranged and emits microwaves to heat the food, a motor that rotates the antenna, a temperature detection means, and a control means to execute the following steps: using the temperature detection means to distinguish between at least two regions of the food accommodated in the heating chamber and detect the temperature of the food; using the temperature detection means to detect the temperature of the region while rotating the antenna that emits microwaves with the motor while the food is accommodated in the heating chamber; calculating the rate of temperature rise of the region based on changes in the temperature of the region over time; correlating the rate of temperature rise of the region with the angle of the antenna; a first step of rotating the antenna with the motor to an angle at which the rate of temperature rise of the region becomes higher than a predetermined value and then stopping the rotation; a second step of heating the food for a predetermined period of time after the first step, and repeating the first and second steps .
Other means will be described in the detailed description of the invention.

This invention makes it possible to automatically set the antenna to an optimal angle so that food can be heated to the target temperature in a short amount of time depending on the type and placement of the food.

1 is a schematic diagram of a cooking device according to an embodiment of the present invention; FIG. 2 is a functional block diagram of the cooking device. 10 is a flowchart of a cooking process. 10 is a graph showing an example of temperature changes of three loads in an angle search process. 10 is a graph showing changes in the antenna angle in the angle search process. 1 is a graph showing temperature changes in two regions during cooking. 10 is a graph showing an example of a temperature increase rate in two types of water cooking. 10 is a graph showing an example of the rate of temperature increase in cooking two types of rice.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic diagram of a cooking device 5 according to this embodiment.
A thermoviewer 56 for detecting the surface temperature of the food 1 to be heated is provided at the upper end of the innermost part of the heating chamber 58. The thermoviewer 56 is a temperature detection means for detecting the temperature of the food 1 separately in the areas 11 and 12.

Heating chamber 58 is a space surrounded by housing 501 and door 502, and is a space for storing food and heating the food.
An antenna 54, a motor 53, and a magnetron 52 are provided below the heating chamber 58. The magnetron 52 supplies microwaves to the inside of the heating chamber 58 via the antenna 54. The motor 53 rotates the rotatable antenna 54 to a desired angle.

In cooking appliances, non-contact temperature measurement devices, such as thermoviewers, are most commonly installed on the upper part of the interior wall. This has the advantage of increasing the distance to the center of the interior, making most of the bottom surface of the heating chamber 58 the detection range. In this embodiment, the thermoviewer 56 is installed at the rear of the upper interior surface of the cooking appliance 5, solving the problem of making most of the bottom surface of the heating chamber 58 the detection range.

FIG. 2 is a functional block diagram of the cooking device 5.
The cooking appliance 5 includes a control unit 51, a magnetron 52, a motor 53, an antenna 54, a touch panel display 55, a thermoviewer 56, a storage unit 57, and a heating chamber 58. The storage unit 57 stores a program 571.

The heating chamber 58 is a portion where food is stored and heated.
The control means 51 is, for example, a combination of a CPU (Central Processing Unit) and RAM (Random Access Memory), and receives input signals from the touch panel display 55, an input signal from a start switch (not shown), a detection signal from the thermo viewer 56, etc. By executing a program 571, the control means 51 controls the magnetron 52, controls the angle of the antenna 54 by the motor 53, and controls the touch panel display 55, etc., based on the input signals and the detection signals.

With food placed in the heating chamber 58, the control means 51 rotates the antenna 54 emitting microwaves using the motor 53, detects the temperature of areas 11 and 12 using the thermoviewer 56, calculates the temperature rise of areas 11 and 12, and correlates the temperature rise rate of areas 11 and 12 with the angle of the antenna 54. After that, the control means 51 rotates the antenna 54 using the motor 53 to an angle where the temperature rise rate of areas 11 and 12 exceeds a predetermined value, and then stops the rotation. Based on the temperature of the food 1 detected by the thermoviewer 56, the control means 51 calculates either the average value, maximum value, or minimum value of the temperature distribution of the food 1. This allows the control means 51 to use appropriate values according to the heating method.

The magnetron 52 supplies microwaves to the interior of the heating chamber 58 via the antenna 54. The motor 53 rotates the rotatable antenna 54 to the desired angle. The touch panel display 55 is a transparent touch panel superimposed on a display, and functions as an operation and display means that accepts operation input and displays the current process.

A thermoviewer 56 is provided at the upper end of the innermost part of heating chamber 58 to detect the temperature distribution in heating chamber 58. This thermoviewer 56 simultaneously detects the temperature of a predetermined area where food to be heated is placed, and can detect the temperature distribution of the food by distinguishing between at least two areas.
The storage unit 57 is configured by, for example, a flash memory or a ROM (Read Only Memory), and stores a program 571. The processing when the control means 51 executes the program 571 is shown, for example, in the flowchart of FIG.

FIG. 3 is a flowchart of the cooking process.
After rotating and stopping the antenna 54 by a predetermined angle (step S10), the control means 51 detects the temperature change in the food areas 11 and 12 by detecting the food temperature distribution on-the-fly for a predetermined period of time (step S11). The control means 51 then calculates a temperature rise value (heating rate) based on the temporal change in the temperature of the food areas 11 and 12 (step S12). In this manner, the control means 51 detects the uneven temperature rise in the food areas 11 and 12 due to differences in the electric field strength distribution depending on the angle of the antenna 54 by the temperature rise. In this embodiment, the temperature rise value is sometimes referred to as the temperature rise rate. The control means may calculate the temperature rise value (heating rate) based on the temporal change in the temperature of at least two or more points on the food, and is not limited to two points.

Then, in step S13, control means 51 determines whether or not the angle search has ended. If the angle search has not ended (No), control means 51 returns to step S10, and if the angle search has ended (Yes), control means 51 proceeds to step S14. Here, control means 51 detects the relationship between the rotation angle of antenna 54 and the temperature rise at each point on the food during one rotation immediately after the start of heating. The processing from steps S11 to S13 is called the angle search process.
The control means 51 searches for the optimum angle of the antenna 54 for each point on the food based on the temperature rise value at each point on the food at each angle of the antenna 54. By repeatedly rotating and stopping the antenna 54 intermittently, it is possible to reduce the amount of data relating to the relationship between the angle of the antenna 54 and the rate of temperature rise, and it is possible to simplify the processing by the control means 51.

Based on the detection result, the control means 51 then controls the rotation angle of the antenna 54 during the remaining heating process so as to make the temperature of each point on the food uniform.
Specifically, the control means 51 calculates the solution of simultaneous linear equations relating to the heating of each point of the food (step S14).

The control means 51 selects a combination of time and angle that constitutes a solution to the simultaneous linear equations, and repeats the processes from steps S15 to S20.
Then, the control means 51 rotates the antenna 54 to the angle related to the selected solution and stops it (step S16), and waits for the time related to the selected solution (step S17).The control means 51 then determines whether the food temperature is equal to or higher than a predetermined value (step S18).

In step S18, if the food temperature is equal to or higher than the predetermined value (Yes), the control means 51 temporarily stops output from the antenna 54. If the food temperature is lower than the predetermined value (No), the control means 51 proceeds to step S20.

In step S20, if there are any combinations of time and angle that constitute solutions to the simultaneous linear equations that have not been selected, the control means 51 returns to step S15. Once the control means 51 has selected all combinations of time and angle that constitute solutions to the simultaneous linear equations, the processing of FIG. 3 ends. In this embodiment, directional heating control is performed in this manner to improve heating efficiency and reduce uneven heating.

The control means 51 may further terminate heating by the antenna 54 during the loop of steps S15 to S20 if the difference between the target temperature of the food 1 and the temperature of each area of the food detected using the thermoviewer 56 is equal to or less than a predetermined value. This allows the cooking appliance 5 to prevent overheating of the food 1 even if there is an error in the temperature rise rate measured (detected) in the angle search process.

Figure 4A is a graph showing an example of the temperature changes of three loads during the angle search process. The vertical axis of the graph shows the temperatures of loads a to c. The solid line shows the temperature of load a. The dotted line shows the temperature of load b. The dashed line shows the temperature of load c. The horizontal axis of the graph shows the elapsed time. Here, loads a to c refer to the various areas of food contained in the heating chamber 58.

Figure 4B is a graph showing changes in the angle of the antenna 54 during the angle search process. The vertical axis of the graph represents the angle of the antenna 54. The horizontal axis of the graph represents the elapsed time, which is the same as the horizontal axis of the graph in Figure 4A. The angle search process refers to the processing from steps S11 to S13 in the flowchart in Figure 3. The control means 51 rotates the antenna 54 by 45 degrees intermittently and associates the angle of the antenna 54 with the temperature rise value of each load, thereby calculating the combination of angle and time that will optimally heat each load.

In the angle search process, the heat quantity Q _in is dominant compared to _{the heat dissipation quantity Q out ,} which can be approximated to 0 as expressed by equation (1).

The amount of heat Q _in is calculated from the mass, specific heat, and temperature change of the food using equation (2), where m is the mass of the food, c is the specific heat of the food, and ΔT is the temperature change.

Using the graphs in Figures 4A and 4B, the amount of temperature rise can be estimated from the product of the temperature rise per unit time and time, ignoring the amount of heat dissipation. This is expressed by equation (3). Equation (3) is the temperature rise matrix per unit time [°C/s]. Each row of the matrix represents loads a to c, and each column of the matrix represents an angle. The element α _a1 in row 1, column 1 is the temperature rise value of load a when the antenna 54 is heated at the first angle. The element α _cβ in row 3, column β is the temperature rise value of load c when the antenna 54 is heated at the β angle.

Equation (4) is a simultaneous linear equation for calculating the temperature rise matrix up to the target temperature in the control process. The left side of equation (4) is the temperature rise matrix [°C] up to the target temperature. In this temperature rise matrix, T _{a_end} is the target temperature of load a, and T _{a_start} is the initial temperature of load a. T _{b_end} is the target temperature of load b, and T _{b_start} is the initial temperature of load b. _{T c_end} is the target temperature of load c, and T _{c_start} is the initial temperature of load c.
The first matrix on the right side of equation (4) is a temperature rise matrix per unit time [°C/s]. The second matrix on the right side of equation (4) is an antenna stop time matrix [s]. The control means 51 solves the simultaneous linear equations of equation (4) and controls the antenna based on the calculated antenna stop time that allows each load to reach the target temperature at the same time.

FIG. 5 is a graph showing temperature changes in two regions during cooking.
The vertical axis of the graph represents temperature, and the horizontal axis of the graph represents elapsed time. The solid line of the graph represents the temperature of region 11 in Figure 1. The dashed line of the graph represents the temperature of region 12 in Figure 1. The dashed line of the graph represents the temperature of food 1 when antenna 54 continues to rotate at a predetermined rotation speed.

The period from time T0 to T1 immediately after the start of heating is the angle search process. During this angle search process, the control means 51 scans the rotation angle of the antenna 54 and the food temperature distribution at at least two points in real time, and detects uneven temperature rise due to differences in the electric field strength distribution from the temperature rise in the food.

The heating process takes place from time T1 to time T4. Based on the detection results, the control means 51 controls the antenna rotation angle for the remaining heating to equalize the temperature of the food. At time T1, the temperature of area 11 is lower than the temperature of area 12. Therefore, the control means 51 rotates the antenna 54 to a first fixed angle at which the temperature rise rate of area 11 is higher than the temperature rise rate of area 12, and then stops it. At this first fixed angle, the average temperature rise rate of areas 11 and 12 is better than at other angles.

At time T1, the antenna 54 stops at a first fixed angle, then starts rotating again at time T2, and at time T3, the antenna 54 stops at a second fixed angle.
At time T2, the temperature of region 12 is lower than the temperature of region 11. Therefore, the control means 51 rotates the antenna 54 to a second fixed angle at which the temperature rise rate of region 12 becomes higher than the temperature rise rate of region 11, and then stops the rotation. At this second fixed angle, the average value of the temperature rise rates of regions 11 and 12 is better than at other angles.
This makes it possible to reduce the temperature difference between the two points compared to the conventional case where the antenna 54 is constantly rotating. Also, by controlling the angle of the antenna 54, the temperature can be increased efficiently, so the food can be heated to the target temperature Tt in a shorter time than in the conventional case. In the conventional case, the food reaches the target temperature Tt at time T5.

FIG. 6 is a graph showing two examples of the rate of temperature increase in heating water.
The vertical axis of the graph indicates the rate of temperature rise in the heating of the two water bodies, and the horizontal axis of the graph indicates the angle of the antenna 54. Note that this graph plots data collected at 45° intervals. The dashed line indicates the rate of temperature rise of the water on the left side. The solid line indicates the rate of temperature rise of the water on the right side. The dashed-dotted line is the average of the rates of temperature rise of the two water bodies.

When heating these two bodies of water, it is possible to first heat them by positioning the antenna 54 at the most efficient angle of 225°, and then heat the water on the right at a relatively efficient angle of 135°, which will suppress the temperature rise of the water on the right.

FIG. 7 is a graph showing an example of the rate of temperature increase in two types of cooked rice.
The vertical axis of the graph indicates the rate of temperature rise when the two rice dishes are heated, and the horizontal axis of the graph indicates the angle of the antenna 54. Note that this graph plots data collected at 45° intervals. The dashed line indicates the rate of temperature rise for the rice dish on the left. The solid line indicates the rate of temperature rise for the rice dish on the right. The dashed-dotted line is the average of the rate of temperature rise for the two rice dishes.

When heating these two bowls of rice, it is conceivable to first heat them with the antenna 54 at the most efficient angle of 180°, and then heat them at a relatively efficient angle of 270°, which can suppress the temperature rise of the water on the left side. It is also conceivable to heat them only at an angle of 270° from the beginning.

This embodiment allows for optimal control of the heating method in accordance with the type of food and its actual placement. This embodiment also reduces uneven heating of food, improves energy efficiency, and shortens heating time.

(Modification)
The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. It is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

The above-mentioned configurations, functions, processing units, processing means, etc. may be implemented in part or in whole by hardware such as an integrated circuit. The above-mentioned configurations, functions, etc. may also be implemented by software, with a processor interpreting and executing a program that implements each function. Information such as the programs, tables, and files that implement each function can be stored in a storage device such as memory, a hard disk, or an SSD (Solid State Drive), or on a storage medium such as a flash memory card or DVD (Digital Versatile Disk).

In each embodiment, the control lines and information lines shown are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are interconnected.
As modified examples of the present invention, for example, the following (a) to (f) are available.

(a) The rotation direction of the antenna is not limited to one direction, but may be bidirectional. This reduces the time it takes for the temperature to rise to a high angle, thereby saving time.
(b) A learning function may be provided for the antenna rotation angle. This makes it possible to find an optimal solution more quickly, thereby saving time.
(c) In this embodiment, the temperature distribution is measured at two points, but the number of measurement points may be three or more.

(d) In the embodiment of FIG. 5, two fixed angles of the antenna are combined, but the fixed angles of the antenna may be only one pattern, or three or more patterns of fixed angles may be combined, and this is not limited thereto.
(e) In the angle search process, the antenna is not limited to being stopped and rotated intermittently, but may be rotated slowly and continuously.
(f) When the temperature of any of the multiple areas of the food is higher than a predetermined value and overheating due to uneven heating is detected, the cooking device may not only temporarily suspend output but also reduce output, thereby preventing overheating of the heated object (food).

1 Food 11, 12 Area 5 Cooker 501 Housing 502 Door 51 Control means 52 Magnetron 53 Motor 54 Antenna 55 Touch panel display 56 Thermoviewer (temperature detection means)
57 Memory unit 571 Program 58 Heating chamber

Claims (4)

a heating chamber containing food;
a rotatably disposed antenna that emits microwaves to heat the food;
a motor that rotates the antenna;
a temperature detection means for detecting the temperature of the food contained in the heating chamber by distinguishing between at least two regions;
With the food placed in the heating chamber, the antenna emitting microwaves is rotated by the motor, the temperature of the region is detected using the temperature detection means, a temperature rise rate of the region is calculated, and the temperature rise rate of the region is associated with an angle of the antenna,
a control means for performing a first process of rotating the antenna by the motor until the angle at which the temperature rise rate of the region becomes higher than a predetermined value and then stopping the rotation, and then performing a second process of heating the food for a predetermined time , and repeating the first process and the second process ;
A heating cooker comprising: The control means, while the food is placed in the heating chamber, rotates the antenna emitting microwaves, uses the temperature detection means to associate a temperature rise rate and an angle of the antenna from the temperatures of at least two regions of the food, and then performs a first process of rotating the antenna with the motor until an angle at which the temperature rise rate of at least the lower temperature region of the two regions is higher than the temperature rise rate of the higher temperature region, and then stops the rotation. Thereafter , the control means performs a second process of heating the food for a predetermined time , and repeats the first process and the second process .
The cooking device according to claim 1 . a heating chamber containing food;
a rotatably disposed antenna that emits microwaves to heat the food;
a motor that rotates the antenna;
A temperature detection means;
A control method for a cooking device including a control means,
a step in which the control means detects the temperature of the food contained in the heating chamber by the temperature detection means, distinguishing between at least two regions of the food;
a step of detecting the temperature of the region using the temperature detection means while rotating the antenna emitting microwaves with the motor while food is placed in the heating chamber;
calculating a temperature rise rate of the region based on a change in temperature of the region over time;
Correlating the temperature rise rate of the region with the angle of the antenna;
a first step of rotating the antenna by the motor to an angle at which a temperature rise rate in the region becomes higher than a predetermined value, and then stopping the rotation;
a step of performing a second step of heating the food for a predetermined time after the first step , and repeating the first step and the second step;
A method for controlling a cooking appliance, comprising: a heating chamber containing food;
a rotatably disposed antenna that emits microwaves to heat the food;
a motor that rotates the antenna;
A temperature detection means;
A control means for a cooking device including:
a step of detecting the temperature of the food contained in the heating chamber by the temperature detection means, distinguishing between at least two regions of the food;
a step of detecting the temperature of the region using the temperature detection means while rotating the antenna emitting microwaves with the motor while food is placed in the heating chamber;
calculating a temperature rise rate of the region based on a change in temperature of the region over time;
Correlating the temperature rise rate of the region with the angle of the antenna;
a first step of rotating the antenna by the motor to an angle at which a temperature rise rate in the region becomes higher than a predetermined value, and then stopping the rotation;
a step of executing a second step of heating the food for a predetermined time after the first step , and repeating the execution of the first step and the second step ;
A control program for executing the above.