JPS6350835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is an automatic cooking method that automatically controls the heating of food by detecting the surface temperature of the food and the water vapor released from the food in high-frequency heating, etc. The purpose is to improve the quality of heating by having the operator input information about the size of the food.

Conventional Structure and Problems In conventional automatic microwave ovens, for example, when heating food, the heating state of the food is detected by detecting the surface temperature of the food and the water vapor released from the food. Therefore, the heating state of the surface of the food is detected, and in the case of a large food, only the surface is heated and the center is not heated, and only the surface state is detected. If the food is small, the difference in temperature between the surface and the center is small and has little effect on the quality of cooking, but when the food is large, the difference in temperature between the surface and the center is large and has a large effect on the quality of cooking.

Conventionally, as shown in Fig. 7, a constant K unique to each type of food is stored in a storage means such as a microcomputer, and when a sensor detects the heating state of the food, the constant K is stored from the start of heating until the sensor detects it. time of
Next, determine the time T ₂ until the end of heating from T ₁ and the constant K specific to the above-mentioned food, and calculate the total heating time.
A system has been developed that automatically controls the heating sequence as shown in FIG. 7 as T ₁ +T ₂ . This is shown in Figure 8, where the constant K was constant regardless of the size of the food. This method has the advantage of being extremely easy to use because it can automatically control heating, but the temperature difference between the center and surface of the food varies depending on the size of the food, resulting in variations in the finished product.

Further, as disclosed in, for example, Japanese Patent Application Laid-open No. 13692/1983, the K constant is determined by estimating the size of the food based on the time T ₁ it takes for the sensor to detect the heating state of the food. something is being developed. This type has the following drawbacks. The reason is that the time it takes for the sensor to detect food varies greatly depending on the initial temperature of the food. The initial temperature of food varies by about 20°C when it is heated immediately after being taken out of the refrigerator, and when it is left indoors. Therefore, the variation in the initial temperature of the food makes accurate cooking difficult. Furthermore, T ₁ hour varies depending on the freshness and moisture content of the food.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and includes a function for the operator to input information regarding the size of the food and a sensor for detecting the heating state of the food. The purpose is to stabilize the Furthermore, the relationship between information regarding the size of the food provided by the operator and the maximum time from the start of heating until the food reaches a predetermined heating state is memorized, and if the food is not detected within the maximum time, the food is placed in the heating chamber. Another purpose is to ensure safety by stopping heating if an abnormality occurs, such as if the sensor is not being heated or if an abnormality has occurred, such as a sensor failure.

Structure of the Invention In order to achieve the above object, the automatic cooking device of the present invention has a function for the operator to input information regarding the size of the food, and a function to detect the surface temperature of the food and water vapor generated from the food to determine the heating state. A sensor to detect and
Count the time T ₁ from the start of heating until the sensor detects a predetermined heating state of the food, select K from the input information regarding the size of the food, and use the constant K and the counted T ₁ . , which calculates the remaining heating time _T2 , which has the effect of calculating the cooking time more accurately, eliminating variations in cooking doneness depending on the size of the food, and enabling even cooking. It is. Further, the relationship between the information regarding the size of the food input from the setting section and the maximum time from the start of heating until the food reaches a predetermined heated state is stored. If the sensor does not detect the predetermined heating state of the food even after this maximum time has elapsed from the start of heating, it is assumed that heating was started without food being added, or that an abnormality such as a sensor malfunction has occurred. It also has the effect of stopping the traffic and ensuring safety.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a perspective view of a microwave oven as an example of an automatic cooking device. 1 is a display section that displays heating output and heating time; 2 is a setting section that has information about the type of cooking, heating output, and food size; and a key for starting cooking; 3 is a heating chamber 4. This is a door that can be opened and closed to take food in and out. 5 is the body.

In FIG. 2, 6 is a magnetron that supplies high frequency waves to the heating chamber 4, and 7 is food as an object to be heated. 8 is a humidity sensor for detecting water vapor generated from food.

In place of the humidity sensor 8, 9 in FIG. 3 is an infrared sensor that detects the surface temperature of the food.

FIG. 4 is an enlarged view of the display section 1 and setting section 2. 1 is a display section. 2 is a setting section.

Menu keys 21 to 23 are used to input the type of food to be heated, and weight keys 24 to 26 are used to input the weight as information related to the size of the food. 27 is a cooking start key for starting heating. 28 is a cancel key for canceling the set menu and weight or stopping heating. 29 is a timer setting knob for setting the heating time.

FIG. 5 shows an electronic circuit for controlling a microwave oven as an embodiment of the present invention. 10 is a microcomputer having functions such as memory, judgment, calculation, and input/output of signals, and A/D ₁ and A/D ₂ are input terminals for A/D conversion. Relays 11 and 12 control power supply to the magnetron 6 in order to control high frequency output. 13 is a fan motor for cooling the magnetron. Although FIG. 5 shows an embodiment in which a humidity sensor 8 is used as a means for detecting the heating state of food, an infrared sensor may be used instead.

FIG. 6 is a diagram showing differences in heating conditions depending on the size of food. In B, the food is large, so the high frequencies are absorbed near the surface of the food and do not reach the center. Therefore, although the surface is heated, the center is not easily heated. A humidity sensor detects water vapor generated from the surface of food. Additionally, the infrared sensor detects the surface temperature of the food. Even if these sensors detect the heating state of the food, it is only the surface heating state, and the center is not heated as much as the surface.
In B, since the food is small, the whole absorbs high frequency waves and the temperature difference is small.

As mentioned above, as the size of the food increases, the temperature at the center becomes lower.To raise this to an appropriate temperature, the heating time _T2 after the sensor detects the temperature increases as the size of the food increases. It is necessary. This includes a constant K as the size of the food increases.
The goal is to increase the As an example, FIG. 9 shows the relationship between food size and constant K for meat M, root vegetables R, and leafy vegetables B as cooking types. By doing so, it is intended to eliminate differences in food quality caused by the size of food and improve the performance of automatic cooking. 10th
The figure shows a method of processing by the microcomputer 10. The microcomputer 10 has a central role in the entire control circuit as shown in FIG. It has functions such as display output, input of key information for the setting section, analysis and calculation of sensor information, and storage. In this embodiment, information on the type and size of food inputted from the setting section 2 is taken. A constant K is determined based on this input information. Then, the food is stored in the heating chamber and the cooking start key 27 of the setting section 2 is pressed.
starts heating the food. Then, for example, the humidity sensor 8 detects the heating state of the food. The humidity sensor 8 is attached near the exhaust port of the heating chamber 4, and detects changes in the humidity of the air discharged from the heating chamber. The humidity sensor 8 is a type of resistor, and its resistance value changes depending on surrounding moisture. It is generally well known that the humidity sensor 8 has a characteristic that the resistance value is small when the surrounding humidity is high, and the resistance value is large when the humidity is low. By detecting this change in resistance value, the microcomputer detects that the food has reached a predetermined heating state. Then, the time T ₁ from the start of heating to the detection is counted, and the remaining heating time T ₂ is calculated from the previously determined constant K and this T ₁ . The method for calculating T ₂ is to multiply the constant K by T ₁ . Then, heating is performed while counting the remaining heating time _T2 , and when the heating is completed, heating is stopped. By determining the constant K and obtaining T ₂ based on the information on the type and size of the food input by the operator in this way, stable and accurate cooking becomes possible. Furthermore, since the K constant is determined based on information regarding the size of the food, the determination of the K constant is not affected by the initial temperature of the food. That is, in the conventional patent application disclosed in Japanese Patent Application Laid-Open No. 56-13692, the constant K is determined based on the time _T1 from the start of heating to the detection by the sensor.
In this case, if the initial temperature of the food is different, T ₁ will be different,
The determination of the constant K becomes inaccurate. In this respect, in the case of the present invention, the constant K is not affected by the initial temperature.
In addition, the relationship between the information regarding the size of the food inputted from the setting section and the maximum time from the start of heating to the specified heating state is memorized, so that even after this maximum time, the sensor does not reach the specified heating state of the food. If the heating state is not detected, it is assumed that an abnormality has occurred and the heating is stopped.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) There is no difference in the finished product depending on the size of the food. Therefore, stable and accurate automatic cooking is possible.

(2) Since the sensor memorizes the maximum time until detection for each size of food, detailed abnormality detection is possible.

(3) Since the setting section 2 is used as the means for inputting information regarding the size of the food, it can be realized at a very low cost.

[Brief explanation of drawings]

Fig. 1 is an external perspective view of a microwave oven according to an embodiment of the present invention, Figs. 2 and 3 are side sectional views of the microwave oven, and Fig. 4 is an enlarged perspective view of the display section and setting section of the microwave oven. Figure 5 is a circuit diagram of the same microwave oven, Figure 6 is a sectional view of main parts showing differences in heating conditions depending on the size of food, Figure 7 is heating time T ₁ ,
_FIG . 8 is a diagram showing the relationship between the conventional food type and food size and the constant K, and FIG. 9 is a diagram showing the relationship between the food type and food size and the constant K in the present invention. FIG. 10 is a flowchart showing the internal processing of the microcomputer. 1...Display section, 2...Setting section, 3...Door, 4
... Heating chamber, 5 ... Main body, 6 ... Magnetron, 7 ... Food (object to be heated), 8 ... Humidity sensor, 9 ... Infrared sensor, 10 ... Microcomputer (microcomputer), 11, 12 ……relay,
13...Fan motor, 21, 22, 23...Menu key, 24, 25, 26...Weight key, 2
7...Cooking start key, 28...Cancel key, 29...
...Timer setting knob.

Claims (1)

[Scope of Claims] 1. A heating chamber that stores an object to be heated, a high-frequency oscillator that supplies high-frequency energy to the heating chamber, a sensor that detects the heating state of the object to be heated, and a setting section that includes the object to be heated. a function of inputting information regarding the size of the sensor, a means for determining a heating time, and a means for controlling heating according to the determined heating time, and the means for determining the heating means controls the sensor from the start of heating. means for counting the time _T1 until it detects that the object to be heated has reached a predetermined heating state; and a means for storing the relationship between the information regarding the size of the food inputted from the setting section and the constant K. a storage means for storing a constant K; a means for selecting a constant K from the storage means based on information regarding the size of the food inputted from the setting section;
Means for calculating a heating time _T2 after the sensor detects that the object to be heated reaches a predetermined state from the counted _T1 hour, and information regarding the size of the food input from the setting section. and the maximum time until the heated object reaches a predetermined heating state, and if the sensor does not detect the predetermined heating state even after the maximum time elapses after heating starts, heating is stopped. Automatic cooking device. 2. The automatic cooking device according to claim 1, wherein the sensor has a function of detecting the surface temperature of the object to be heated. 3. The automatic cooking device according to claim 1, wherein the sensor is configured to detect water vapor released from the heated object as a function of detecting the heating state of the heated object. 4. The automatic cooking device according to claim 2, wherein the sensor is configured to detect infrared rays emitted from the surface of the heated object as a function of detecting the heating state of the heated object. 5. The automatic cooking device according to claim 1, wherein the constant K increases as the size of the object to be heated increases.