JPH0730921B2 - Cooking device - Google Patents

Description

TECHNICAL FIELD The present invention detects the concentration of water vapor or combustible gas emitted from a food according to the heating state of the food, and detects the weight of the food to heat the food. The present invention relates to a cooker that realizes automatic heating cooking that changes the conditions to be performed and finishes the food in the most desirable heating state.

Conventional technology Regarding automatic heating and cooking of foods
Stop heating or change the heating means by detecting the state of water vapor or combustible gas that comes out from the food according to the heating condition of the food and comparing it with the state before heating or the state after a certain time after starting heating (Japanese Patent Laid-Open No. 55-841
21 and JP-A-58-18035). These cookers have the following problems.

Problems to be solved by the invention As a reference value of the heating state to be compared with the heating state of the food detected by the atmosphere sensor during heating, the state before heating or the state after a certain time from the start of heating are stored and compared. Used when doing. Since the reference value is fixed in this way, the heating menu selection keys are provided according to the type of food, or automatic heating is performed for specific menus only when the atmospheric conditions such as the initial environmental conditions are stable. I realized cooking.

However, in such an automatic heating cooker, if the number of menus for automatic cooking is increased, the number of heating menu keys on the operation section will only increase, and it is easy to make a mistake when using it, the area of the operation section will increase, and the environmental initial conditions will increase. There is a problem that there is a restriction on the condition and that atmospheric conditions are stable.

For example, Japanese Patent Laid-Open No. 55-84121 discloses a cooking device that can automatically adjust the temperature of the sake liquor by using a gas sensor that detects alcohol, and is limited to a heating menu called sake liquor. It can be adopted.
Further, in Japanese Patent Laid-Open No. 58-18035, heating control for discriminating the type of food is performed only when grill heating is performed, and can be used only when the menu is grill heating. That is, there is a problem that a selection menu key for limiting the heating menu is provided. Furthermore, since these patent publications use the sensor signal before heating or the sensor output after a fixed time after heating as a reference for comparison, the food is stored under limited environmental initial conditions or stable atmospheric conditions. There was a problem that had to be heated.

The present invention is to solve the above problems, using an atmosphere sensor for detecting the water vapor concentration and the combustible gas concentration and a weight sensor for detecting the food weight, and finely detecting and determining the heating state of the food, Determine the type and quantity,
The present invention provides a cooking device that realizes a small number of heating menu selection keys for a large number of foods and quantities by controlling the timing of stopping heating and switching the heating capacity.

Means for Solving the Problems The cooking device of the present invention is a heating chamber for storing food, a heating means for heating the food, and a steam output and a combustible gas concentration in the heating chamber. The atmosphere sensor to be replaced with, the weight sensor for detecting the weight of the food placed in the heating chamber and replacing it with an electric output signal, and the electric output signal obtained by the atmosphere sensor and the weight sensor sequentially from the start of heating the food are stored. Based on the type or quantity of food, the storage means, the first computing means for sequentially calculating the rate of change of the electrical output signal, the second computing means for calculating the differential value which is the rate of change of the rate of change. Comparison means for comparing the reference value of the predetermined change rate and differential value with the change rate and differential value calculated by the first and second calculating means, and the result of comparison and determination by the comparing means. And a control means for controlling the heating means based on the above, and an electric output signal of an atmosphere sensor according to the concentration of water vapor or heating gas emitted from the food heated by the heating means, and according to a change in the weight of the food. The electrical output signal of the weight sensor, the rate of change of the two types of electrical output signals, and the differential value that is the rate of change of the rate of change, based on the result of comparison with a reference value, The control means is configured to control the heating means.

Action The cooker of the present invention starts heating the food by heating means for performing heating such as microwave heating, radiant heating, or convection heating, and the electricity of the atmosphere sensor obtained according to the concentration of water vapor or combustible gas emitted from the food. Output signal voltage and its change rate and differential value (change rate of change rate) change, and the electric output signal of the weight sensor obtained according to the weight of the food placed in the heating chamber changes It is configured to determine the content of food by comparing the situation etc. with a preset reference value, and stop heating by the control means or switch the heating capacity, and what kind of food is food after starting heating of cooking. It is possible to automatically set the heating method and the heating time to determine whether the food is suitable, and to perform the heating suitable for the food. Realize the reason.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, the atmosphere sensor used in the present invention will be described. As shown in FIGS. 2 and 3, the atmosphere sensor shown here has a characteristic that the resistance value decreases as the water vapor concentration increases, and the resistance value increases as the combustible gas concentration increases. The increase and decrease change in the opposite direction as the change in the resistance value of the sensor.

In this way, whether the resistance value increases or decreases with one atmosphere sensor, whether the combustible gas concentration is increasing or the water vapor concentration is increasing,
Therefore, such an atmosphere sensor is called an atmosphere sensor capable of distinguishing and detecting the water vapor concentration and the combustible gas concentration.
Incidentally, FIGS. 2 and 3 are graphs observed with the concentrations of the combustible gas and water vapor, which are the parameter elements, kept constant. Further, a sensor for discriminating and detecting water vapor or heatable gas does not have to be given by a functional expression as shown in FIG. 2 and FIG. It suffices to have a correlation characteristic that

Furthermore, here, the identification detection in which the resistance value changes in the opposite direction as one atmosphere sensor was shown, but if the two atmosphere sensors detect water vapor and combustible gas individually and the resistance changes in the opposite direction, this The atmosphere sensor used in the present invention can be realized by connecting two atmosphere sensors in series.

Now, the cooking device of the present invention will be described. FIG. 4 is a perspective view of the microwave heating cooker according to the present invention. A door 16 is pivotally supported on the front surface of the main body 15 so as to be openable and closable, and an operation panel 1 is arranged. On the operation panel 1, several automatic heating cooker selection keys 2 are provided.

FIG. 1 is a block diagram showing the configuration of the present invention. The command input from the automatic cooking selection key 2 on the operation panel 1 is decoded by the control unit 3. Then, the control unit 3 controls the food to be heated placed on the rotary mounting table 11 in the heating chamber 10.
Start heating 12 The heating is performed by driving a magnetron, which is the microwave generation means 7, through a driver. or,
The control unit 3 includes a control unit, a storage unit, a first calculation unit, a second calculation unit, and a comparison unit, and the atmosphere sensor 9 in the middle of heating stores a signal from the weight sensor 14. , Calculation, comparison, etc.

In addition, the wind generated by the blower fan 6 while the food is being heated is the magnetron 7, the turntable motor 13 or the weight sensor.
Electric components such as 14 are cooled, and steam and combustible gas that come out of foods through the heating chamber are included and go out of the machine through the exhaust passage 8. The atmosphere sensor 9 provided in the exhaust passage 8 discriminates and detects the water vapor concentration and the heatable gas concentration and detects the detection circuit 5.
The sensor signal is transmitted to the control unit 3 via. On the other hand, the weight of the food 12 is transmitted to the weight sensor 14 on the rotary shaft of the rotary mounting table 11 and converted into an electric signal voltage, which passes through the detection circuit 5 and the control unit 3
The sensor signal to.

In this way, observe how the alcohol concentration as the combustible gas concentration changes and the water vapor concentration changes when the sake is smoked, and check how the signal voltage of the atmosphere sensor changes. It is FIG. 5 that was observed whether it changed. FIG. 5 (A) shows the case of continuous heating with microwaves. (B) shows that the combustible gas concentration (alcohol) sharply increases at the beginning of heating and becomes saturated with the lapse of time. (C) shows the change of the water vapor concentration when (i) 90cc (b) 180cc (c) 360cc of three kinds of liquor was smoked.
(D) shows the output change of the sensor signal voltage when the sake is smoked with the above three kinds of sake. In the early stages of burning the concentration of combustible gas has a greater influence on the atmosphere sensor than the concentration of water vapor, so the sensor signal voltage increases, but over time, the influence of water vapor concentration becomes higher and the sensor signal voltage increases. It will start to decrease.

The change in the sensor signal voltage when the sake is smoked is sequentially stored in the storage unit of the control unit 3 as the sensor signal voltage,
The change rate of the sensor signal voltage is sequentially calculated by the first calculation means and stored in the storage means, and the change rate (differential value) of the change rate is sequentially calculated by the second calculation means and stored in the storage means. The comparison means compares the stored value of the sensor signal voltage value, the rate of change, or the rate of change (differential value) of the rate of change with the reference value for determining the food type or the food item menu type according to the quantity.

For these, in FIG. 6, the sensor signal voltage when the sake is smoked obtained in FIG. 5 is shown in (B). Then, from the state of the voltage change of the sensor signal voltage (B),
Whether the amount of change in the sensor signal voltage per unit time is increasing or decreasing as the sensor signal change rate is sequentially calculated by the first calculating means and stored in the storage means, and the content thereof is changed as the sensor signal change rate with time. The state of change with time is shown in (C). Further, whether or not the change amount per unit time in the sensor signal change rate of (C) is increasing or decreasing as the sensor signal change rate (differential value) is sequentially calculated by the second calculating means and stored in the storage means. The state of change that is stored and the sensor signal change rate (differential value) over time is shown in (D).

On the other hand, what happens to the sensor signal voltage, what is the sensor signal change rate, and what is the change rate (differential value) of the sensor signal change rate when the food that has been heated once is reheated? Fig. 7 shows the observation of miso soup. Foods that have been cooked once, such as miso soup, do not contain combustible gas components such as alcohol in sake, so even if the atmosphere sensor has a function to detect combustible gas components, the sensor signal voltage will change. What appears is a change in the sensor signal voltage that follows the change in the concentration of water vapor that comes out from food such as miso soup. As a result, the state of the sensor signal change rate or the change rate (differential value) of the sensor signal change rate is significantly different from that when drinking sake (comparison between FIG. 7 and FIG. 6).

In this way, when reheating foods that do not contain alcohol combustible gas components or foods that have been heated by cooking once, most of the water vapor comes out of the foods, as is the case when burning sake. Even with continuous heating, the changes in the sensor signal voltage, the sensor signal change rate, and the change rate (differential value) in the sensor signal change rate are different. Therefore, even in the case of microwave continuous heating in which food and sake liquor in the reheat menu are heated with the same selection menu key, it is determined whether the liquor liquor or the reheat menu is changed by changing the sensor signal voltage and the sensor. The signal change rate and the sensor signal change rate change rate (differential value) can be determined based on a preset reference value.

Here, the reference value for distinguishing between the reheating menu and the sake liquor will be described.

Description will be made by comparing the contents of the above table with FIGS. 6 and 7. First of all, the difference in the sensor signal voltage between the first liquor and the reheating menu is that the signal is different between when liquor is heated and when it is reheated compared to when the food is heated. The voltage is applied in the opposite direction (+ and-) to the specified value (Δ
h) The judgment is made by confirming whether the value is larger than that. For example, in FIG. 6 (B), (a) cannot accurately determine whether or not the sake is smoked because the value of Δh is not exceeded. Since (b) and (c) are exceeded, it is determined to be a sake liquor. Δh is determined in advance at the design stage, taking into consideration variations in the initial environment, variations in the sensor, and variations in mechanical vibration when the turntable starts rotating. It is a value. The second determination method is the first polarity (+;
The third method is to check whether the change rate is zero or not when the polarity of the sensor signal change rate changes from positive to negative. Further, as a fourth method, it is determined whether or not the time interval when the polarity of the change rate (differential value) of the signal change rate changes is within a predetermined time (a ≦ Ta ≦ b). That is, FIG. 6 (D) shows a case where the above-mentioned time interval Ta determined on the design stage based on the experimental result is within the predetermined time periods a and b. On the other hand, in FIG. 7, no change in polarity can be seen no matter where Ta is used.

As described above, the reason why the food type is discriminated by paying attention to a plurality of items is that the presence or absence of the heating gas (alcohol) is used by first using the ability of the atmosphere sensor to detect the discrimination by comparing the sensor signal voltages. The second reason is to check whether the polarity of the sensor signal change rate is positive or negative, because the presence or absence of combustible gas can be reconfirmed by this, and the third is that the value of the sensor signal change rate is zero. What it means to see is to see that the sensor signal voltage does not show a sequential change, and the flammable gas concentration and the water vapor concentration change the influence value of the resistance value of the atmosphere sensor. This is because it is possible to confirm that they are in a balanced state. Fourth, at the time interval Ta, even when microwaves or electromagnetic waves from relay contacts or semiconductor elements are superimposed on the sensor signal voltage. It is possible to identify that it is a change in the signal voltage due to combustion gas.

This is because the microwave leaking from the heating chamber is likely to leak in synchronization with the rotation stage of the rotary mounting table, the radio wave agitating blade, or the rotating waveguide for improving the radio wave distribution in the heating chamber. And appears as an instantaneous change in signal voltage. It also appears in the sensor signal change rate and the change rate (differential value) of the sensor signal change rate. The appearance of the rate of change of the sensor signal change rate appears as pulses at intervals of a few tens of seconds, and its shape appears continuously (one cycle) over both polarities of + and-. Therefore, it is possible to easily remove from the detection signal in consideration of these conditions. Also, electromagnetic wave noise from a relay or a semiconductor element can be similarly explained because it is an instantaneous signal change. As described above, since a plurality of items are discriminated, it is possible to discriminate whether the liquor is hot or reheated during heating even if the liquor is hot and reheated with one heating menu selection key. Therefore, it is not necessary to provide a heating menu selection key (liquor soup) for limiting foods called sake liquor, and the number of complicated heating menu selection keys of the operation unit can be reduced, which has the effect of reducing erroneous operation machines. In addition to the atmosphere sensor signal voltage, the rate of change in the atmosphere sensor signal voltage and the rate of change in this rate of change determine the type of food. There is no possibility of making a mistake in determining the type of food due to variations or variations in the sensor signal voltage after a lapse of a certain time after the start of heating. That is, these variations do not appear in the rate of change of the sensor signal voltage and the rate of change of the rate of change because they are constant terms.

Further, by practicing the present invention, the food will not be overheated and ignited. The reason will be described with reference to FIG. This is when the food is put into the heating chamber for manual heating and continuous heating is performed, and the cooking setting time is too long for the amount of food, and the user took his eyes off after heating the food. It's time. First, after Tc time from the start of heating, steam of food comes out and the sensor signal voltage starts to change. After that, when heating progresses up to Td time, steam disappears. When the food is dried and the heating is continued, the signal voltage changes in the opposite direction to that when the concentration of water vapor increases due to the increase of combustible gas from around Te. Then, this change is the value of ΔF (value determined in advance at the design stage)
Even if some charring is made by stopping the heating at the time Tf, it is possible to prevent the food from catching fire.

The above is the effect of the atmosphere sensor. On the other hand, the function of the weight sensor will be described below with reference to FIG.

There are stewed dishes, dishes such as curry stew, and cooked dishes such as cooked rice as menus for cooking in the microwave oven, but these menus have individual heating and cooking selection keys, and there are many I was cooking by selecting from the menu keys. However, by carrying out the present invention, it is possible to obtain good heating finish by heating with the same cooking selection key as for reheating food or drinking sake.

As a concrete means, first of all, since the total weight of the food including the container is much heavier than stewed / curry / rice cooked or reheated or sake liquor, the weight sensor 14 indicates the weight of the food at the same time as the heating. Is detected and goes through the detection circuit 5 to the control unit 3
It is transmitted to the memory means and stored in the storage means, and at the same time, the comparison means determines whether it is larger or smaller than the value W ₀ previously stored as a weight value for distinguishing the stewed / curry / cooked rice.・ Proceed with heating as cooked rice, and when it is small, proceed with reheating or heating as sake liquor. The reason why this total weight is extremely large is that a container weighing 2000 grams called a special casserole is used. (Refer to Fig. 9D) Also, the change in the humidity sensor signal voltage is different between reheating and simmering / curry / cooking, and simmering / curry / cooking can be discriminated and separated from reheating based on the value of the humidity detection time T _1. Since it is so large, the food material can be identified not only by the weight of the food at the start of heating but also by the change in humidity during heating. That is, in FIG. 9, (b)
It is the humidity sensor signal voltage when 1 cup of miso soup, 1 cup of rice and yakisoba is heated, and (c) is the humidity sensor signal voltage in the case of simmering, curry and cooking rice,
There is a clear difference in the elapsed time of the humidity sensor signal voltage between the food of the group (b) and the food of the group (c). This difference is consistent with the group difference when foods are classified according to the food weight in (d).

When it is a food material such as stew, curry, and rice, heating in the boiling state is continued as a heating procedure, and it is switched from high-heat heating to low-heat heating in anticipation of deterioration or deformation of the food itself. By applying this low heat, the food becomes soft and mellow in taste, and a good heating condition can be realized.

In this way, when boiling, currying, or cooking rice, it is necessary to keep the boiling state for a while, but as a result of investigating how long it should be heated, when using a dedicated casserole, It was found that this can be achieved by heating on high heat until the water evaporates.

Utilizing this fact, the present invention realizes automatic heating cooking such as simmering, curry, and rice cooking. This will be described with reference to FIGS. 10 and 1.

When the ingredients for cooking, curry, and rice are put in a special casserole and heated on high heat, the gross weight of the food is detected and judged at the beginning of heating, and then the humidity sensor indicates the time when heating on high heat is continued.
Humidity is detected at T ₁ . At this time, it can be judged that the food has started to boil.

Further, the weight sensor 14 detects a change in the weight of the food as a weight sensor signal voltage, and obtains a time T ₂ when the water evaporates after T _{1 at the} start of boiling and the weight becomes β times the initial weight B.
The heating output is switched at the time of T ₂ as the timing for switching the heating output. Then, low power heating is performed for a time K times as long as T ₂ .

By heating this additional heating for K * T ₂ time, the food is softened and the taste is soaked, and the quality of the food material is altered to increase the mellowness and flavor.

The weight change coefficient β that gives the time T ₂ at which the heating output is switched is given as a function of the food weight W and the weight sensor signal change rate C. The rate of evaporation of water from food depends on the rate of change c of the weight sensor signal. Since the weight sensor signal change rate c is determined depending on the type of food, the weight change coefficient β and the weight sensor signal change rate c corresponding to each food such as stew, curry, and cooked rice can be obtained in advance. Therefore, by comparing these during heating, the heating time suitable for the food menu can be set.
[Β = G (w, c)] Effects of the Invention As described above, the cooking device of the present invention can detect the weight of food including the atmosphere sensor 9 and the container, which distinguishes and detects the steam concentration and the combustible gas concentration and replaces them with an electric output signal. A weight sensor 14 that detects and replaces with an electric output signal, a storage unit that stores the electric output signals obtained from the atmosphere sensor 9 and the weight sensor 14, and a first calculation that sequentially calculates the rate of change of these electric signals. Means, second calculating means for calculating a differential value which is the change rate of the change rate, differentiating the change rate calculated by the first and second calculating means with a predetermined reference value of the change rate and the differential value. The automatic heating and cooking selection key is provided with a comparison means for comparing the value with a value and a control means for determining the content of the food by the comparison means and stopping the heating of the food as a result, or switching the heating capacity. Just one It is possible to re-heating Toka stew, curry, rice, etc., such as Kang Toka rice, miso soup, fried noodles in a good heating finished state.

Therefore, in the conventional case, one for sake and one for reheat,
1 for stew, 1 for curry stew, 1 for cooked rice,
The above five automatic heating selection keys are combined into one, and the complicated automatic heating selection keys on the operation panel are simplified, and there is an effect that the chance of erroneous operation when selecting a desired operation key is reduced.

Further, even if the initial condition of the environmental atmosphere is not stable, it is possible to realize a good heating state without making a mistake in the food menu by checking the change rate of the sensor signal or the differential value.

Furthermore, since it has a heating gas detection function, it is not limited to automatic heating cooking, but even if manual heating by manual operation is detected, some heating gas comes out from the food and heating is stopped to overheat the food. It has the effect of preventing a situation that causes a fire.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a cooking device according to an embodiment of the present invention, and FIG. 2 is a water vapor detection characteristic diagram of the atmosphere sensor,
FIG. 3 is a characteristic diagram of flammable gas detection of the atmosphere sensor, FIG. 4 is an external perspective view of the cooking device, and FIG. 5 is a characteristic diagram showing a change in sensor signal voltage with the progress of heating the sake. The figure shows the characteristics of the rate of change and the rate of change of the rate of change from the sequential change of the sensor signal voltage, and the characteristics of the figure are shown in Fig. 7. Fig. 7 shows the time when the same miso soup was reheated. FIG. 9 is a characteristic diagram showing how the sensor signal voltage changes with time, and FIG. 8 is a characteristic diagram showing how the sensor signal changes with time when the food starts to be overheated and charred. figure the relationship between the humidity detection time T ₁ corresponding to the food weight shows how the aging of the sensor signal when the heating such as re-soluble heat food and stew curry rice such as the miso soup, rice, noodles The characteristic diagram shown in Fig. 10 is the time course when the same stewed food was heated. It is a characteristic view of the manner in which changes in Toka Toka differential value sensor signal voltage Toka signal change rate with. 2 ... Automatic cooking selection key, 3 ... Control part, 7 ... Magnetron, 9 ... Atmosphere sensor, 12 ... Food, 14 ...
Weight sensor.

Claims (1)

[Claims] 1. A heating chamber for containing food, a heating means for heating the food, an atmosphere sensor for discriminating and detecting a water vapor concentration and a combustible gas concentration in the heating chamber and replacing them with an electric output signal, and a heating chamber in the heating chamber. A weight sensor that detects the weight of the food to be placed and replaces it with an electrical output signal, a storage means that stores the electrical output signal obtained by the atmosphere sensor and the weight sensor sequentially from the start of heating the food, and the electrical output signal First calculation means for sequentially calculating the change rate, second calculation means for calculating a differential value which is the change rate of the change rate, and a reference for the change rate and the differential value predetermined based on the type or quantity of food. The heating means is controlled based on the comparison means for comparing the value with the change rate and the differential value calculated by the first and second calculation means, and the result of the comparison judgment by the comparison means. And an electric output signal of the atmosphere sensor according to the concentration of water vapor or combustible gas emitted from the food heated by the heating means, and an electric output signal of the weight sensor according to the weight change of the food. When,
The control means controls the heating means on the basis of the comparison result between the change rate of the two types of electrical output signals and the differential value which is the change rate of the change rate with respect to a reference value. Cooker.