JP2012247074A - Heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating cooker capable of determining a cooking time according to a loading quantity.SOLUTION: The heating cooker has a microwave generating means 1, a heating chamber 2 housing a load, an infrared sensor 3 measuring the temperature the load in noncontact manner, a moisture sensor 5 measuring a vapor quantity generated from the load, a control means 6 controlling the output of the microwave generating means 1, a boiling detecting means 7 detecting the boiling of the load from a detected value from the moisture sensor 5, and a load quantity determining means 8 determining the load quantity, the load quantity determining means 8 carries out compensation by the detected value of the infrared sensor 3 when starting the measurement of an integral power when determining the load quantity from the integral power till the boiling detecting means 7 determines the boiling, thereby there is no need for a user to input the load quantity, and it becomes possible to accurately detecting a temperature of the load, consequently it becomes possible to determine the precise load quantity, the heating time can be decided according to the load quantity.

Description

  The present invention relates to a cooking device used in general homes, restaurants, offices, and the like.

  Conventionally, in this type of heating cooker, a method for determining the heating time from the input load amount and correcting the heating time based on the load temperature, which is the detection result of the infrared sensor that measures the temperature in a non-contact manner, is disclosed. (For example, refer to Patent Document 1).

  In addition, a method is disclosed in which a load is measured using a weight sensor, and heating is performed by adjusting the output of the microwave in accordance with the load (see, for example, Patent Document 2).

JP 2002-181332 A JP-A-7-181074

  However, the conventional configuration has a problem that the operation becomes complicated because the user needs to input the amount of load. Moreover, when the load amount input by the user is different from the actual amount, the load is overheated even if the heating time is corrected by the load temperature measured by the infrared sensor.

  Further, the conventional configuration for measuring the weight has a problem that the configuration becomes complicated.

  The present invention determines a load amount by accurately detecting the temperature of the load, determines a heating time according to the load amount, eliminates overheating, and further heats the load to an appropriate temperature. The purpose is to provide.

  The heating cooker of the present invention measures microwave generation means, a heating chamber for storing a load heated by microwaves, an infrared sensor for measuring the temperature of the load in a non-contact manner, and the amount of steam generated from the load. A humidity sensor; a control means for controlling the output of the microwave generation means based on the detection value of the infrared sensor or the humidity sensor; a boiling detection means for detecting boiling of the load from the detection value of the humidity sensor; and a load Load amount determination means for determining the amount of the load, and when the load amount determination means determines the load amount from the integrated power until the boiling detection means detects boiling, the load amount determination means starts the measurement of the integrated power Correction was made with the detection value of the infrared sensor.

  According to the heating cooker of the present invention, it is not necessary for the user to input the amount of load, and the temperature of the load can be accurately detected. Therefore, it is possible to provide a heating cooker capable of performing automatic heating cooking with a good finish in order to determine the heating time according to the above.

Sectional drawing which shows the heating cooker in Embodiment 1 of this invention. The characteristic view showing the change of load temperature and electric power of the heating cooker in Embodiment 1 of the present invention The characteristic view showing the detection value of the humidity sensor of the heating cooker in Embodiment 1 of this invention The characteristic view which showed the relationship between the detection temperature of the infrared sensor of the heating cooker in Embodiment 1 of this invention, and load temperature

  The first invention is a microwave generating means, a heating chamber for storing a load heated by microwaves, an infrared sensor for measuring the temperature of the load in a non-contact manner, and a humidity sensor for measuring the amount of steam generated from the load. A control means for controlling the output of the microwave generation means based on a detection value of the infrared sensor or the humidity sensor, a boiling detection means for detecting boiling of the load from the detection value of the humidity sensor, and an amount of the load Load amount determining means for determining the load amount, and when the load amount determining means determines the load amount from the integrated power until the boiling detection means detects the boiling, the infrared sensor when starting the measurement of the integrated power By using a heating cooker that is corrected with the detected value, it is not necessary for the user to input the amount of load, and the finish is determined automatically to determine the load amount and determine the heating time. It is possible to provide a good automatic cooking capable cooker.

  The second invention has load temperature estimation means for estimating the temperature of the load from the detection value of the infrared sensor when the boiling detection means detects boiling, particularly in the cooking device of the first invention, and the load It is necessary to have a complicated configuration by determining the amount of load in the heating chamber from the integrated power required when the temperature estimated by the temperature estimation means rises from the first predetermined temperature to the second predetermined temperature. It is possible to detect an accurate load amount even if there is no heat, and to realize a heating cooker that can be cooked automatically without underheating or overheating to determine the heating time according to the load amount Can do.

  According to a third aspect of the present invention, in particular, in the cooking device of the second aspect, the load temperature estimating means is effective from the time when the temperature increase of the infrared sensor after the start of heating becomes constant, so that By ignoring information during periods when the load temperature and the measured temperature of the infrared sensor are not proportional, it is possible to more accurately determine the load amount, and underheating or overheating to determine the heating time according to the load amount It is possible to realize a heating cooker that can cook automatically without becoming.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
In FIG. 1, sectional drawing of the heating cooker of Embodiment 1 of this invention is shown. The cooking device of the present embodiment includes a microwave generating means 1, a heating chamber 2 that stores a load heated by microwaves, an infrared sensor 3 that measures the temperature of the load in a non-contact manner, and steam generated from the load. The humidity sensor 5 for measuring the amount, the control means 6 for controlling the output of the microwave generating means 1 based on the detection value of the infrared sensor 3 or the humidity sensor 5, and the boiling of the load is detected from the detection value of the humidity sensor 5. It has boiling detection means 7 and load amount determination means 8 for determining the amount of load.

  The microwave generating means 1 usually uses a magnetron in many cases, but may be a semiconductor type. The microwave generation means 1 generates microwaves by supplying power from an inverter circuit (not shown) based on an instruction from the control means 6. The microwave to be generated is normally 2450 MHz, but is not limited thereto.

  Microwaves are introduced into the heating chamber 2 via an antenna, and a structure in which a turntable is provided so that the antenna is fixed and the load is rotated, and the load is placed at the same position so that the antenna is rotated. There are cases where it is configured.

  The heating chamber 2 is made of metal such as aluminum or SUS, and the load is heated by placing the load in the heating chamber 2 and introducing the microwave generated by the microwave generating means 1 into the heating chamber 2. The Although microwaves exist in the heating chamber 2, it is ideal that only the load is heated by the microwaves. Therefore, when the heating chamber 2 is made of, for example, glass, the glass generates heat due to microwaves, resulting in a heating loss. Therefore, in order to reduce the heating loss, it is desirable to use a metal that does not generate heat by the microwave and reflects the microwave. However, since it is necessary to introduce the microwave generated from the microwave generating means 1 into the heating chamber 2, only that portion is usually changed to another material.

  The infrared sensor 3 detects the temperature in a non-contact manner, and includes a thermal type thermopile and a bolometer, a quantum type photodiode, and a phototransistor, but any type may be used. In particular, some thermopiles have a plurality of elements in one package, and each element can detect a temperature at a different position. Usually, in such an element, the temperature of each element is often taken out and used in many cases, but is not limited thereto. The infrared sensor 3 is connected to the control means 6 and the load amount determination means 8 and is used to control the microwave generation means 1 and to determine the load amount.

  The movable part 4 is provided with the infrared sensor 3 and allows the infrared sensor 3 to measure different positions in the heating chamber 2 by moving the movable part 4. The use of a stepping motor is suitable for the movable portion 4 because the measurement position is determined, but a linear motor or the like may be used. A rotary encoder may be used for positioning. The movable part 4 may move the infrared sensor 3 in a one-dimensional manner or in a two-dimensional manner.

  The humidity sensor 5 detects steam (humidity) generated from the load. When the humidity sensor 5 is installed in the heating chamber 2, problems such as heat resistance and noise generation occur, and thus the humidity sensor 5 is installed in the exhaust port 10. The humidity sensor 5 includes a relative humidity sensor and an absolute humidity sensor, but either one may be used.

  In the embodiment of the present invention, the humidity sensor 5 is used for detecting the boiling of the load. However, if the application is limited to the detection of boiling, the humidity sensor 5 may be replaced with a temperature sensor with good response. . That is, when the load boils, steam is generated, and the steam touches the temperature sensor, and the temperature detected by the temperature sensor starts to rise. Therefore, the boiling of the load can be detected from the temperature rise. In this case, a temperature sensor used as a substitute for the humidity sensor 5 is preferably disposed in the heating chamber 2, and the upper part is more preferable than the lower part because it is easier to detect steam.

  The control means 6 is connected to the microwave generation means 1, the infrared sensor 3, the movable part 4, and the like. When the user sets a heating pattern, time, or the like by an operation unit (not shown), the control unit 6 operates an inverter circuit (not shown) to supply power to the microwave generation unit 1, and the microwave generation unit 1 Generate microwaves. The control means 6 moves the movable part 4, measures the temperature of the load placed in the heating chamber 2 by the infrared sensor 3, changes the operating state of the microwave generation means 1 according to the result, and uses the load Control is performed such as stopping the operation of the microwave generating means 1 after heating to a temperature desired by the person. The control means 6 is often a microcomputer, a DSP, a custom IC, or the like, but is not limited thereto.

The boiling detection means 7 is connected to the humidity sensor 5 and detects the boiling of the load from the detected value. The detection result of the boiling detection means 7 is sent to the control means 6, and the control means 6 changes the power supplied to the microwave generation means 1 according to the result.

  The load amount determination means 8 determines the amount of load in the heating chamber 2, the result is transmitted to the control means 6, and the control means 6 changes the control method according to the load amount. The load amount determination means 8 and the control means 6 may be the same.

  About the cooking-by-heating machine comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The user opens a door (not shown) and places a load in the heating chamber 2. In FIG. 1, the microwave generated by the microwave generating means 1 is introduced into the heating chamber 2 from a rotating antenna. Since the antenna rotates, the distribution of the microwave in the heating chamber 2 changes every moment, and the microwave is heated no matter where the load is placed in the heating chamber 2. Therefore, in the cooking device having such a configuration, the user may place the load anywhere in the heating chamber 2, but when the antenna is fixed and the load is rotated, the rotation for rotating the load is performed. Since the platform exists, the user needs to place the load on the turntable, but either configuration may be used.

  The user determines a heating method by an operation unit (not shown). Usually, in the case of such a heating cooker, several heating methods, such as microwave heating, heater heating, oven heating, and steam heating, can be selected. In this embodiment, the case of heating with microwaves will be described. In addition, there are a manual mode in which the user sets the output and time for heating, and an automatic mode in which the heating is automatically controlled if the cooking content is selected. When the user selects them and the door is closed, heating can be started.

  When heating is started, the control means 6 supplies power to the microwave generation means 1, and the control means 6 moves the infrared sensor 3 by the movable part 4, and the infrared sensor 3 measures the temperature in the heating chamber 2. The control means 6 receives the temperature information and changes the control content.

  For example, when a course for automatically heating a drink is selected, heating is continued until the set temperature is reached, and when the set temperature is reached, the operation of the microwave generating means 1 is stopped and the heating is ended. To do.

  Since heating by microwaves directly heats the load, the amount of heating is proportional to the amount of load. In order to determine the heating amount according to the amount of load, there are a method in which the user inputs the load amount using an input means, or a method using a weight sensor.

  In that case, since it is necessary for the user to input the amount of load, there is a problem that the operation becomes complicated. Moreover, when the load amount input by the user is different from the actual amount, the load is overheated or the heating is insufficient.

  In addition, the configuration for measuring the weight has a problem that the configuration becomes complicated. In particular, in the case of a configuration that does not have a turntable for placing a load, a configuration in which a placement table is provided on the weight sensor is conceivable. It had the problem of increasing time and effort. Moreover, since the food which is a load is normally put into a container and heated, unless the weight of a container is registered beforehand, the temperature of the load which is originally required cannot be measured. Therefore, it was necessary to register the weight of the container, and the cooking device was inconvenient to use.

  As other methods for determining the load amount, there are a method for determining from the amount of electric power used to increase the temperature of the load and a method for determining from the gradient of the temperature increase of the load.

  As a method of measuring the temperature of the load, the infrared sensor 3 is often used. However, since it is difficult to provide the infrared sensor 3 on the ceiling of the heating chamber 2 due to dirt and the like, it is often attached to the upper portion of the wall surface of the heating chamber 2. In this case, when the bottom of the container into which the load is placed is deep, the load becomes a blind spot of the container. Therefore, the infrared sensor 3 detects the temperature of the container, and the temperature of the load cannot be measured. . Therefore, the load amount is determined from the temperature rise of the container, and there is a problem that the error is large.

  In addition, when the determination is made from the amount of electric power used to increase the temperature of the load, it largely depends on the initial temperature of the load. Therefore, if the initial temperature of the load cannot be corrected, a large load amount determination error occurs. There is a problem that the initial temperature of the load cannot be measured when the load is a blind spot of the infrared sensor 3 as described above.

  As a method for determining the load amount, a method for determining from the amount of power used to increase the temperature of the load will be described. FIG. 2 is a diagram showing the temperature rise of the load and the change in power. When the temperature of the load is A, heating is started with electric power α, the temperature of the load reaches B at time Ta, and further, heating is continued and the temperature of the load reaches C at time Tb. . At this time, for example, the electric power input during the time Ta to Tb is obtained by (Tb−Ta) * α. Since the temperature rise at that time is (C−B), the load amount can be determined from the relationship between the power and the temperature rise.

  The problem here is that the temperature of the load cannot be measured as described above. However, in the embodiment of the present invention, the humidity sensor 5 is provided. A method in which the boiling detection means 7 detects boiling using the detection value of the humidity sensor 5 will be described.

  FIG. 3 is a diagram illustrating the detection value of the humidity sensor. When the microwave generating means 1 is driven to heat the load, the moisture contained in the load is released as steam by heating. As the heating proceeds, the amount of the released steam increases and eventually reaches boiling at time Ta and releases a large amount of steam. That is, the increase rate (inclination) of the detection value of the humidity sensor 5 before reaching the time Ta is different from the increase rate of the detection value of the humidity sensor 5 after the time Ta, that is, after boiling. Therefore, the boiling detection means 7 can detect boiling from the change in the increase rate.

  At this time, the amount of steam generated varies depending on the load amount, but the timing at which the amount of steam increases is the time when it reaches boiling. In addition, no matter what vessel the load is placed in, there is no change in the amount of steam generated, so temperature information that the load has boiled can be detected without being affected by the load amount or the vessel. Further, since the generated steam is surely exhausted from the exhaust port 10 and is not affected by the shape of the container, it is possible to reliably obtain temperature information that the load has boiled.

  However, in order to determine the load amount, two temperatures of the load are necessary as described above. One has temperature information of boiling, but another temperature information is necessary. Next, the method will be described.

  FIG. 4 is a diagram showing the relationship between the detected temperature of the infrared sensor 3 and the load temperature. In FIG. 4, the solid line indicates the detection temperature of the infrared sensor 3, and the dotted line indicates the temperature of the load.

  In FIG. 4A, when electric power is supplied to the microwave generating means 1 and heating is started, the temperature of the load rises in proportion to time, and at time Tc, it boils and does not rise above that temperature. Therefore, the temperature E should be approximately 100 ° C. at normal atmospheric pressure. The detected temperature of the infrared sensor 3 at that time is the temperature D, which is different from the temperature E which is the boiling temperature of the load.

  This is because the infrared sensor 3 looks at the temperature of the container instead of the temperature of the load as described above. However, the fact that the temperature of the load is the temperature E indicating 100 ° C. is apparent from the fact that the boiling detection means 7 detects the boiling. Therefore, it can be determined that the detected temperature of the infrared sensor 3 in this case is lower by (ED) than the actual load temperature. That is, since the boiling detection means 7 detects boiling at time Tc, it can be understood that the difference between the detected temperature of the infrared sensor 3 and the boiling temperature of 100 ° C. is the error of the infrared sensor 3.

  FIG. 4B shows an example in which the container is put in a different container. In this case, it can be seen that the error is larger. Although not shown, depending on the container, the load may not enter the blind spot of the container, and the temperature of the load and the detection temperature of the infrared sensor 3 may be substantially the same.

  In this way, when the error between the detected temperature of the infrared sensor 3 and the actual load temperature is corrected, and the load amount determining means 8 determines the load amount using the corrected detected temperature of the infrared sensor 3. Therefore, it is possible to accurately determine the load amount.

  The load amount determined by the load amount determination unit 8 is sent to the control unit 6, and information on the load amount is used according to the load and the heating content. For example, when the load is frozen food and the user gives an instruction by an input means (not shown) to try thawing, the control means 6 calculates the optimum power amount from the load amount and inputs the power amount When the heating is finished, it is possible to control to stop heating.

  Furthermore, the load temperature estimation means 9 is provided, and by correcting the temperature detected by the infrared sensor 3, the load amount can be determined in any case.

  For example, an error when determining the load amount increases between a cold state immediately after the load before heating is taken out of the refrigerator and a warm state. Therefore, a load amount determination method that does not depend on the initial temperature is required.

  The load temperature estimation means 9 detects the difference between the load temperature and the load temperature from the difference between the detected temperature of the infrared sensor 3 and the boiling temperature of 100 ° C. when the boiling detection means 7 detects boiling as described above. Since the detected temperature of the infrared sensor 3 and the temperature of the load have a substantially proportional relationship as shown in FIG. 4, the difference between the detected temperature of the infrared sensor 3 and the temperature of the load is substantially constant. Therefore, if the detected temperature of the infrared sensor 3 is known, the load temperature can be estimated.

  For example, in FIG. 4, power integration is started from the time (Tb) when the detected temperature of the infrared sensor 3 reaches the temperature B. At time Tc, the boiling detection means 7 detects boiling. The detected temperature of the infrared sensor 3 at that time is the temperature D. However, since the actual load temperature is 100 ° C., the difference between the temperature detected by the infrared sensor 3 and the load temperature is (100−D). The accumulated electric power is accumulated between (Tc−Tb), and the initial temperature is (B + 100−D) obtained by adding an error (100−D) to the temperature B to obtain the load amount. The determination means 8 determines the load amount.

  Further, since the load temperature can be estimated as described above, the period during which the integrated power is calculated may be any temperature period. Therefore, the load amount determination unit 8 uses the first predetermined temperature as the temperature estimated by the load temperature estimation unit 9. The load amount in the heating chamber 2 can be determined from the integrated power required when the temperature rises to the second predetermined temperature.

Conversely, if there is no load temperature estimating means 9, for example, the detected temperature of the infrared sensor 3 is B.
Even if an attempt is made to determine the amount of load from the integrated power until the temperature rises by 30 ° C., it cannot be calculated if the load boils before reaching that temperature. Therefore, the load temperature estimating means 9 can estimate the temperature of the load, thereby making a determination in an arbitrary temperature period.

  However, as can be seen from FIG. 4, the detected temperature of the infrared sensor 3 is not proportional to the load temperature in the initial stage of heating. The detected temperature of the infrared sensor 3 is proportional to the load temperature after the rising gradient of the detected temperature of the infrared sensor 3 becomes constant. Therefore, the load temperature estimating means 9 determines the detected temperature of the infrared sensor 3 thereafter. By estimating the load temperature, it is possible to accurately estimate the load temperature.

  The control means 6, the boiling detection means 7, the load amount determination means 8, and the load temperature estimation means 9 may be independent, or some or all of them may be one. In many cases, a microcomputer, a DSP, a custom IC, or the like is used, but the present invention is not limited thereto.

  As described above, the configuration as in the embodiment of the present invention eliminates the need for the user to input the amount of load and enables accurate detection of the temperature of the load. A load amount can be determined, and a cooking device capable of automatic cooking with good finish can be provided to determine the heating time according to the load amount.

  As described above, the heating cooker according to the present invention does not require the user to input the amount of load, and can accurately detect the temperature of the load, thereby enabling accurate load amount determination. The heating time is determined in accordance with the load amount, so that automatic cooking with a good finish can be performed, which is useful for cooking appliances used in general households and business use.

DESCRIPTION OF SYMBOLS 1 Microwave generation means 2 Heating chamber 3 Infrared sensor 4 Movable part 5 Humidity sensor 6 Control means 7 Boiling detection means 8 Load amount determination means 9 Load temperature estimation means 10 Exhaust port

Claims (3)

Microwave generation means;
A heating chamber for storing a load heated by microwaves;
An infrared sensor that measures the temperature of the load without contact;
A humidity sensor that measures the amount of steam generated from the load;
Control means for controlling the output of the microwave generation means based on the detection value of the infrared sensor or the humidity sensor;
Boiling detection means for detecting the boiling of the load from the detection value of the humidity sensor;
Load amount determination means for determining the amount of load,
When the load amount determination means determines the load amount from the integrated power until the boiling detection means detects the boiling, heating cooking is performed such that the detection value of the infrared sensor at the start of measurement of the integrated power is corrected. vessel. Load temperature estimating means for estimating the temperature of the load from the detection value of the infrared sensor when the boiling detecting means detects boiling, and the temperature estimated by the load temperature estimating means is changed from the first predetermined temperature to the second temperature. The heating cooker according to claim 1, wherein the amount of load in the heating chamber is determined from the integrated power required when the temperature rises to a predetermined temperature. The cooking device according to claim 2, wherein the load temperature estimating means is effective from the time when the temperature rise of the infrared sensor after the start of heating becomes constant.