JPS63204029A - Cooking device - Google Patents

Abstract

PURPOSE:To permit the cooking of various kinds and weights of food with a few heating menu selecting keys, by a method wherein an atmosphere sensor, discriminating and detecting the concentration of water vapor and the concentration of combustible gas, is employed to detect and decide the heating condition of the food delicately. CONSTITUTION:A control unit 3 starts the heating of a food 12 or a substance to be heated, which is put on a turn table 11 in a heating chamber 10. Heating is effected by a microwave generating means 7 or a magnetron through a driver 4. The control unit 3 is provided with a memory means, an operating means and a comparing means to store, operate, and, compare a signal from an atmosphere sensor 9 during heating. Airflow, generated by a ventilating fan 6 during heating a food, cools electric applicances such as the magnetron 7, a turn table motor 13 or the like, thereafter, passes through the inside of the heating chamber 10 and is discharged through an exhaust passageway 8 while entraining water vapor or combustible gas, coming out of the food. The atmosphere sensor 9, provided in the exhaust passageway 8, discriminates and detects the concentrations of water vapor and combustible gas and transmits a sensor signal to the control unit 3 through a detecting circuit 5.

Description

Detailed Description of the Invention: Industrial Application Field The present invention detects the concentration of water vapor or combustible gas emitted from the food according to the heating state of the food, changes the conditions for heating the food, and detects the most desirable heating state. The present invention relates to a cooking device that realizes automatic heating and cooking.

Conventional technology Regarding the conventional automatic cooking of food,
It detects the state of water vapor and combustible gas coming out of the food depending on the heating condition of the food, and compares the state before heating and the state after a certain period of time after the start of heating. (Tokuko Sho 55-)
84121, Japanese Patent Publication No. 58-18035).

These cookers have the following problems.

Problems to be Solved by the Invention The heating state of the food detected by an atmosphere sensor during heating is compared with the heating state. The state before heating or the state after a certain period of time from the start of heating is stored and compared as a reference value for the heating state. It is used on occasion. Since the reference value is set as a fixed condition in this way, when the initial environmental conditions or stable atmospheric conditions are present, a heating menu selection key may be provided depending on the type of food, or a heating method may be used only for a specific menu. This enabled automatic heating and cooking.

However, with the number of heating menu keys on the operation panel increasing, it is easy to make mistakes when using it.
There are problems such as the area of the operating section becoming larger and the number of operational steps required before starting cooking, and problems such as restrictions on the initial environmental conditions and the requirement that the atmospheric conditions be stable.

For example, in Japanese Patent Publication No. 55-84121, a gas sensor that detects alcohol is used to realize a cooker that can automatically adjust the temperature of sake sake, and can be used only for the heating menu of sake sake. It is something. Further, in Japanese Patent Publication No. 68-18035, heating control is performed to discriminate the type of food only when grill heating is performed, and it can be adopted only when the menu is grill heating. There was a problem in that a selection menu key was provided to limit the selection menu for heating the tabs.

Furthermore, these patents use sensor signals before heating or sensor output after a certain period of time from the start of heating as standards for comparison; The problem was that it had to be heated.

The present invention is intended to solve the above-mentioned problems, and uses an atmosphere sensor that distinguishes and detects water vapor concentration and combustible gas concentration to finely detect and judge the degree of heating of food, and to determine the type and amount of food. To provide a cooking device that controls the timing of stopping heating, switching heating capacity, switching heating means, etc., and realizes a large number of foods and quantities with a small number of heating menu selection keys.

Means for Solving the Problems In order to achieve the above object, the cooking device of the present invention distinguishes and detects at least the water vapor concentration and the combustible gas concentration in the heating chamber that are generated when food is heated, and outputs an electrical output signal. An atmosphere sensor to be replaced, a storage means for storing electrical output signals such as water vapor concentration and combustible gas concentration in the heat chamber obtained by the atmosphere sensor sequentially from the start of heating food, and a storage means for storing electrical output signals such as water vapor concentration and combustible gas concentration in the heat chamber, and a change rate of the electrical signal of the atmosphere sensor sequentially. a first calculation means for calculating a differential value, which is a rate of change of the rate of change; It has a comparison means for comparing the rate of change calculated by the second calculation means and the differential value, and a control means for stopping the heating of the food or switching the heating capacity or the heating means as a result of the determination by the comparison means.

Function: The cooking device of the present invention starts heating the food by microwave heating, radiant heating, convection heating, etc., and generates an electrical output signal from the atmosphere sensor according to the concentration of water vapor or combustible gas coming out of the food. Determine whether the rate of change and the differential value of the voltage (rate of change of the rate of change) increase or decrease, when the rate of change becomes smaller, and when the sensor output signal becomes the same as the initial sensor output signal. The system uses a comparison means to determine the type of food, and a control means to stop the heating or change the heating capacity or heating means.After starting cooking, it determines what type of food the food is and automatically selects the heating method and heating time. By setting the , it is possible to perform heating suitable for the food and realize automatic heating cooking that achieves the temperature at which it is ready to eat or when it is cooked.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings.

First, the atmosphere sensor used in the present invention will be explained. As shown in Figures 2 and 3, the atmosphere sensor shown here has the characteristic that the resistance II decreases as the water vapor concentration increases, and the resistance value increases as the flammable gas concentration increases. The increases and decreases in the resistance value of the sensor change in opposite directions as changes in the resistance value of the sensor. In this way, a single atmosphere sensor can determine whether the flammable gas concentration is increasing or the water vapor temperature is increasing based on the increase or decrease in resistance value, so such an atmosphere sensor can distinguish between water vapor concentration and combustible gas concentration. It's called an atmosphere sensor.

By the way, in Figures 2 and 3, the parameters are graphs observed with the concentrations of combustible gas and water vapor constant. It does not have to be given by a functional expression as shown in FIGS. 2 and 3, and it is sufficient that each element has mutually opposite positive or negative correlation characteristics.

Furthermore, here we have shown discrimination detection in which the resistance value changes in opposite directions using one atmosphere sensor, but if water vapor and combustible gas are detected individually with two atmosphere sensors and the resistance values change in opposite directions, this The atmosphere sensor used in the present invention can be realized by connecting two atmosphere sensors in series.

For example, if the sensor is not limited to water vapor and combustible gases, a PTC thermistor or NTC thermistor that senses temperature can also be connected in series or in parallel to realize an atmosphere sensor that can detect a wide range of discrimination.

Now, the cooking device of the present invention will be explained.

FIG. 4 is a perspective view of the microwave cooking device according to the present invention. A door body is pivotally supported on the front side of the main body 16 so that it can be opened and closed freely.
An operation panel 1 is arranged. Several automatic heating cooking selection keys 2 are provided on the operation panel 1.

FIG. 1 is a block diagram showing the configuration of the present invention. Commands inputted from the automatic heating cooking selection key 2 on the operation panel 1 are decoded by the control section 3. As shown in FIG.

Then, the control unit 3 starts heating the food 12, which is the object to be heated, placed on the rotary mounting table 11 in the heating chamber 1o. Heating is performed by driving a magnetron, which is a microwave generating means 7, via a driver 4. Further, the control section 3 is provided with storage means, calculation means, comparison means, etc. to store, calculate, compare, etc. the signals from the atmosphere sensor during heating.

In addition, during the heating of food, the air generated by 1/6 of the air blower cools electrical components such as the magnetron 7 and the turntable motor 13, and passes through the heating chamber 10 and exhausts water vapor and flammable gases coming out of the food. Exit the aircraft via Route 8. An atmosphere sensor 9 provided in the exhaust path 8 discriminately detects water vapor transport and combustible gas concentration, and transmits a sensor signal to the control section 3 via the detection circuit 5.

In this way, we observed how the alcohol concentration changes as a combustible gas concentration and how the water vapor concentration changes when sake is heated, and we also observed how the signal voltage of the atmosphere sensor changes. Figure 6 shows the observed changes. In Figure 5, the presence or absence of heating indicates continuous microwave heating, and the flammable gas concentration indicates that the flammable gas concentration (alcohol) increases rapidly at the beginning of heating and reaches a certain degree of saturation. It shows. Water vapor concentration: H)9occ, (b)180CC1
(c) It shows how the water vapor concentration changes when three types of sake are heated in amounts of 360CC1. and,
For the C/S signal voltage, (a) 9ocC1 (b) 180c
Either the change in combustible gas concentration or the change in water vapor concentration with the amount of three types of alcohol (C1fJ360cc) is influenced by a variable element that has a large effect on the change in resistance value of the atmosphere sensor.

The sensor signal voltage is sequentially stored in the storage means of the control unit 3, and the change in the sensor signal voltage when the sake is heated in this manner.
The first calculation means successively calculates the rate of change in the sensor signal voltage and stores it in the storage means, and the second calculation means successively calculates the rate of change (differential value) of the change rate and stores it in the storage means. The stored values of these sensor signal voltage values, rate of change, and rate of change (differential value) of the rate of change are compared with reference values that are already used to distinguish one type of food menu based on food ingredients and quantities. do. Regarding these, FIG. 6 shows the sensor signal change rate and the change rate (differential value) of the sensor signal change rate when the sake obtained in FIG. 5 is heated.

On the other hand, when food that has been heated once is reheated, what happens to the sensor signal voltage, how does the rate of change of the sensor signal change, and what does the rate of change (differential value) of the rate of change of the sensor signal change? Figure 7 shows what we observed for miso soup. Foods like miso soup that have been cooked once do not contain flammable gas components like the alcohol in sake. Even if the atmosphere sensor has a function to detect combustible gas components, what appears as a change in the sensor signal voltage is a change in the sensor signal voltage that follows a change in the concentration of water vapor coming out of a food such as miso soup. As a result, the rate of change of the sensor signal and the rate of change (differential value) of the sensor signal change rate are significantly different from those when warming sake (
Comparison of Figures 7 and 6).

In this way, when food that is not likely to contain alcohol combustible gas components or food that has been warmed by cooking is reheated, most of the water vapor that comes out from the food is similar to when warming sake. Even if continuous heating is performed, the changes in the sensor signal voltage, the rate of change in the sensor signal, and the rate of change (differential value) of the rate of change in the sensor signal differ. Therefore, even if continuous microwave heating is performed using the same selection menu key to heat the food on the reheating menu and the food on the reheating menu, whether the food is on the reheating menu or the reheating menu can be determined based on the change in the sensor signal voltage. The rate of change and the rate of change (differential value) of the sensor signal change rate can be determined based on preset reference values.

Here, a reference value for distinguishing between a reheated menu and a warmed sake will be explained.

Explanation will be given by comparing the contents of the above table with FIGS. 6 and 7. First of all, the difference in the change in sensor signal voltage between the sake warming and reheating menus is that the signal voltage goes in the opposite direction (+ and -) for sake warming and reheating, respectively, compared to the state when food heating starts. The second method of discrimination is to check whether the value is larger than a predetermined value (Δh).The second method of discrimination is to determine whether the initial polarity of the sensor signal change rate (+: increase, -: decrease) is positive or negative. The third method is to check whether the polarity of the sensor signal change rate changes from positive to negative, and whether or not the change rate sometimes becomes zero. The determination is made by checking whether the time interval when the polarity of the rate of change (differential value) of the signal change rate changes is within a predetermined time (a≦T≦b).

In this way, the reason why food is discriminated based on multiple items is that the first sensor signal voltage is compared. Regarding polarity, the presence or absence of combustible gas (alcohol) is determined by the ability of the atmosphere sensor to identify and detect it.The third step is to check whether the rate of change becomes zero or not until the sensor signal voltage does not show any sequential changes. This shows that the combustible gas concentration and the water vapor concentration are in a balanced state in terms of their influence on changing the resistance value of the atmosphere sensor, and in the allowable range where the fourth TaO value is obtained, the senna signal Even when microwaves, electromagnetic waves from relay contacts, or semiconductor elements are superimposed on the voltage, it is possible to identify changes in signal voltage due to combustible gas. This is because the microwaves leaking from the heating chamber tend to leak in synchronization with the rotation period of the rotating mounting table, radio wave stirring blades, and rotating waveguides that improve the radio wave distribution in the heating chamber, so the sensor signal voltage changes every few seconds. This is because even if a change occurs, it is an instantaneous signal voltage change and appears as a change in the sensor signal change rate, but the change is not visible as a change rate (differential value) of the sensor signal change rate. A similar explanation can also be given to electromagnetic wave noise from relays and semiconductor devices, as they are instantaneous signal changes. As described above, even if sake is warmed and reheated using a single heating menu selection key, it is possible to determine whether the sake is hot or reheated during the heating process, in order to make determinations regarding a plurality of items. Therefore, there is no need to provide a heating menu selection key (warm sake) that restricts the foods called hot sake, and the number of complicated heating menu selection keys on the operation unit is reduced, which has the effect of reducing the chance of erroneous operation. In addition, since the type of food is determined based on two types of factors in addition to the atmosphere sensor signal voltage, there are variations in the initial value of the sensor signal voltage determined by the environmental atmosphere at the initial stage of heating, and variations in the sensor signal voltage over a certain period of time after the start of heating. etc., the type of food will not be mistakenly determined.

Furthermore, by implementing the present invention, food products will not be overheated and ignited. The reason for this is explained by looking at Figure 8. This happens when food is placed in the heating chamber and heated continuously during manual cooking, and the cooking time setting is too long for the amount of food. This is the time when the user takes his eyes off the food after heating has started.Tc time after heating starts, water vapor from the food starts to come out and the sensor signal voltage starts to change, and then the heating starts at Td waiting time. As the temperature progresses, no more water vapor comes out, and as the food continues to dry and heating continues, flammable gas gradually comes out from around To.
Due to this increase in combustible gas, the sensor signal voltage changes in the opposite direction to that when the water vapor concentration increases, and when this change reaches the value of ΔF, heating is stopped at Tf to prevent some charring. Although it is possible, it is effective in preventing food from igniting.

Effects of the Invention As described above, the cooking appliance of the present invention includes an atmosphere sensor for identifying and detecting the concentration of combustible gas and water vapor, a storage means for storing the signals of the atmosphere sensor, and a first calculation for producing the rate of change of the sensor signal. an atmosphere sensor that can be obtained sequentially from the start of heating the food, comprising a means for calculating the rate of change, a second calculation means for calculating the rate of change of the rate of change, a comparison means for determining the type of food, and a control means for stopping the heating of the food. Control is performed by comparing the signal, the rate of change of the sensor signal, the rate of change of this sensor signal rate of change, and a predetermined reference value to determine the content of the food, apply heating appropriate to the food, and then stop heating. In addition, there is no limited menu key for sake warming, and satisfactory heating can be obtained with the same heating menu selection key as the reheating menu, which has the effect of reducing the number of selection keys. This method has the effect of eliminating mistakes in determining food menus even if the environmental atmosphere conditions at the initial stage of heating cooking vary slightly.Furthermore, it is possible to heat food not only in automatic heating cooking but also in manual heating. This has the effect of preventing food from igniting by detecting that a small amount of flammable gas is coming out of the food and stopping the heating.

[Brief explanation of the drawing]

FIG. 1 is a groove diagram showing the configuration of a cooking device in an embodiment of the present invention, FIG. 2 is a water vapor detection characteristic diagram of the same atmosphere sensor,
Figure 3 is a combustible gas detection characteristic diagram of the same atmosphere sensor, Figure 4 is a perspective view of the same exterior, Figure 5 is a characteristic diagram showing changes in sensor signal voltage as the same layer is heated, and Figure 6 is the same. A characteristic diagram showing the changes over time when the rate of change and the rate of change of the change rate are calculated from successive changes in the sensor signal voltage. Figure 7 shows the changes over time when the same miso soup is reheated. FIG. 8 is a characteristic diagram showing how the sensor signal voltage changes over time, and FIG. 8 is a characteristic diagram showing how the sensor signal changes over time when the same food is overheated and begins to burn. 2... Automatic heating cooking selection key, 3...
Control unit, 9... Atmosphere sensor, 7...
Magnetron, 12... Food. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Diagram (H) yI< aKaku & (XI(XX) P
PMW) Figure 3 (8) ffi 27)” deep and shallow (XIα seconds PPMW)
Figure 4 Figure 5 Figure 6 Figure 7 Figure 81!

Claims (1)

[Claims] an atmosphere sensor that distinguishes and detects the water vapor concentration and combustible gas concentration in the heating chamber and converts it into an electrical output signal; a storage means that stores the electrical output signals obtained by the atmosphere sensor sequentially from the start of heating the food; A first calculating means for sequentially calculating the rate of change of the electrical signal, a second calculating means for calculating a differential value which is the rate of change of the said rate of change, and a rate of change and differential value predetermined according to the type or amount of food. a comparison means for comparing the reference value of the value and the rate of change and the differential value calculated by the first and second calculation means; and a comparison means for stopping the heating of the food or determining the heating capacity or heating as a result determined by the comparison means. an electrical output signal of the atmosphere sensor, a change rate of the electrical output signal, and a change in the change rate according to the concentration of water vapor or combustible gas emitted from the food by the heating means; The cooking device is configured such that the comparison means determines whether the rate of change increases or decreases or when the rate of change becomes the smallest, and the control means stops heating or switches the heating capacity or heating means.