JPS58124121A - Heating cooker - Google Patents

Abstract

PURPOSE:To improve the operation of the heating cooker which can perform heating by heater and heating by high frequency by a method wherein a cooking chamber cooling time is operated and displayed by a microcomputer based on an initial temperature of the cooking chamber being heated, a desired temperature of the cooking chamber and a heat time constant necessary for cooling the inside of the cooking chamber. CONSTITUTION:In the heating by high frequency after the heating by heater, a microcomputer 26 stores the cooking chamber temperature T1 at the completion of the heater heating inputted from a heat sensitive element 17 and also the desired cooking chamber temperature inputted from a keyboard 20. The microcomputer 26 operates the cooling time of the inside of the cooking chamber along a particular program on the base of said inputs from the element 17 and keyboard 20 as well as the heat time constant K necessary for cooling the chamber inside which is preliminarily stored therein and displays the result in a display tube 21. Then, maintaining the stop condition of signal outputs to various electric parts, discounting the cooling time, the microcomputer 26 informs, when the time is discounted up, of this effect. Such an arrangement makes the heating cooker to be easy to use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present application relates to a cooking device having two heating means, a heater and a high frequency oscillator.

Conventionally, when using a heating cooker for this type of food, such as an open range, continuously, if the internal temperature set for the previously completed heating cooking is higher than the internal temperature for the next heating cooking, the actual Because the temperature inside the refrigerator is higher than the desired temperature, cooking cannot be performed immediately, and it is necessary to wait until the temperature inside the refrigerator drops to the desired temperature. However, in conventional heating cookers, there is no means to notify the current temperature inside the refrigerator, and there is also a means to inform the user of the cooling time required for the internal temperature to drop to the next desired temperature. There was no. For this reason, operators rely on intuition and experience and wait for the temperature inside the refrigerator to drop, but when the actual temperature inside the refrigerator is not suitable for the food to be heated, they may start cooking. This often resulted in poor final results. Furthermore, when cooking is performed using high-frequency energy after heating with a heater, the air in the heating chamber and the exhaust guide is extremely hot. Generally, the humidity of high temperature air is lower than that of low temperature air. When cooking with a heater, the air has a high temperature of 100 to 250 degrees Celsius, so the humidity is almost 0%. In this state, when the heated object absorbs high frequency energy and steam is generated from the heated object, the change in the humidity of the air in the exhaust guide is extremely small and does not appear as a change in the resistance value of the humidity sensing element. cases are often seen. Therefore, in this case as well, it was necessary to wait until the temperature inside the refrigerator came down. However, in the past, there was no way to notify the cooling time required for the internal temperature to drop to the desired temperature, and cooking often started when the internal temperature was high, making it impossible to detect the generation of steam from the heated items. However, I often failed to cook.

The present invention solves the above-mentioned conventional drawbacks, and aims to improve usability by displaying the time required for the temperature inside the refrigerator to cool down to a predetermined temperature.

In order to achieve the above object, the heating cooker of the present invention has the following basic configuration.

In FIG. 4, T1 is the internal temperature of the heating cooker that was used first, and T2 is the internal temperature of the next heating cooker, or the humidity sensing element when cooking using high frequency energy is subsequently performed. This is the humidity inside the refrigerator where changes in steam can be detected. Further, τC is originally a time not required for cooling. Further T
c' is the cooling time during which the operator relied on his experience and waited for the temperature inside the refrigerator to drop. The end of the drawing (, Tc/ ) Ta 0
In other words, when heating is started from the time when the temperature inside the refrigerator is higher than the desired temperature inside the refrigerator, the object to be heated is heated in the refrigerator at a high temperature for the time Tmu τS, and the final Finishing 6 The page finish is far from the desired finish. Furthermore, in the case of cooking using high frequency energy, steam from the object to be heated cannot be detected, resulting in failure of cooking.

Therefore, the present invention incorporates a microcomputer (hereinafter abbreviated as "microcomputer") and controls the system through its functions. This microcomputer plays a central role in the control circuit, and further controls the external circuit based on information obtained from the external circuit and by analyzing the information. It also has the ability to convert input information into other information or data.

Furthermore, the cooling time required for the temperature inside the cooking device to reach a desired temperature corresponds one-to-one to the difference between the current temperature inside the refrigerator and the desired temperature inside the refrigerator.

That is, the relationship between the previous or current internal temperature T1 and the desired internal temperature T2 and cooling time Tc is Tc=
It is given by the relational expression =K (TI-T2).

Here, K is a constant, which is a unique thermal time constant of the cooking device, and is determined by experiment. That is, page 6 shows that the cooling time Tc can be determined by the difference between the internal temperature of each of the fixed thermal time constants x1, TI, and T2. Therefore, the above-mentioned cooling time relational expression is stored in the microcomputer, furthermore, the current internal temperature T1 is inputted to the microcomputer via the heat-sensitive element and stored as data, and further,
The desired internal temperature τ2 is input into the microcomputer by operating the keyboard and is stored as data. If the subsequent cooking is heating using a heater, the internal temperature T2 can be determined by directly setting the internal temperature on the keyboard. Further, in the case of cooking using high frequency energy, the internal temperature at which humidity can be selectively detected in the cooking mode is determined in advance through experiments. The temperature inside the refrigerator can be converted into data and stored in the microcomputer. By inputting the above data, the microcomputer calculates the cooling time Tc in the central processing section, outputs the result to the display tube, and stops the device from shifting to cooking operation during the cooling period.

That is, when the operator presses the setting key on the keyboard to set the desired temperature inside the refrigerator, the microcomputer memorizes the temperature inside the refrigerator, and then the operator gives a command to start heating to the microcomputer. At the same time as the page internal temperature is input as data via the heat-sensitive element, the microcomputer calculates the cooling time based on the given data using the above-mentioned relational expression. The calculated cooling time is displayed on the display tube and counted down every second or every unit time.

Further, when this command to start heating is given to the microcomputer, the microcomputer holds the output of the output signal from the output terminal to each electric component in a stopped state.

When the cooling time displayed on the display tube reaches 0, the microcomputer notifies the operator that the cooling time has ended. The notification means may be a buzzer or other means. With this configuration, the operator can cool down the cooking device without relying on intuition or experience, and can also know the cooling time, making it possible to obtain a more stable final finish for the heated object. .

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a heater serving as a heat source of the cooking device. The input terminal 6 of the heater 1 protrudes outside the heating chamber 3 through a small hole 5 which is fixed to the lower part of the heating chamber 3 with a fixture 2 made of a heat-resistant material. When power is supplied to this input terminal 6, the heater 1 becomes high temperature, raising the temperature inside the heating chamber 3 and cooking the object 7 placed inside the heating chamber 3 at the high temperature. .

Also, 8 shown in Fig. 1 is a high frequency oscillator, which has a 2450M
Oscillates H2O high frequency energy. The high frequency energy oscillated by the high frequency oscillator 8 is radiated from the antenna 9 of the high frequency oscillator 8 into the waveguide 1o. The high frequency energy radiated into the waveguide 1o propagates through the waveguide 1o and is radiated into the heating chamber 3 through an opening 11 provided in the upper plate 14 of the heating chamber 3. The high frequency energy radiated from the opening 11 is absorbed by the object to be heated 7 placed in the heating chamber 3 and heats the object to be heated 7 from inside the object to be heated 7 .

In addition, the high frequency oscillator 8 has self-heating due to internal loss.
During oscillation, it is cooled by a proa fan 12 to prevent damage. After cooling the high-frequency oscillator 8, the air sent out through the proafan 12 is sent to the heating chamber 3 through a small hole group 13 provided in the rear plate 4 of the heating chamber 3. The air sent to the heating chamber 3 passes through the upper plate 14 of the heating chamber 3 along with steam generated from the object to be heated 7.
It passes through the small hole group B15 provided in the heating chamber 3 and the exhaust guide 16 connecting the heating chamber 3 and the outside of the cooking device, and is exhausted to the outside of the cooking device.

Further, a heat-sensitive element 17 is attached near the heater 1 of the heating chamber 3 to detect the internal temperature of the heating chamber 3 and to control the internal temperature. This heat-sensitive element 7 is an element whose electric resistance value changes in response to changes in the temperature inside the refrigerator, and a thermistor is generally well known. The internal temperature of the heating chamber 3 is controlled to a temperature suitable for cooking by the function of the heat-sensitive element 17 and a control circuit described later.

Further, a moisture sensing element 18 is attached to the exhaust guide 16 to detect changes in the steam discharged from the heating chamber 3. The function of this moisture sensing element 18 is that when the object to be heated 71o reaches a temperature of nearly 10°C during cooking using high frequency energy, from that point on, the object to be heated 7
This is to detect the steam coming out. Due to the function of this moisture sensing element 18 and the control circuit described later,
It is detected that the object to be heated 7 has been heated and cooked to the optimum state during heating by high frequency energy. Further, reference numeral 19 shown in FIG. 1 is a door attached to be openable and closable, and is provided to allow the object to be heated 7 to be taken in and taken out from the heating chamber 3.

Next, according to FIG. 2, the configuration of the control panel section of the heating cooker will be explained in detail.

17) 41 in the figure is a control panel that includes a keyboard 2o and a cooking mode for setting the internal temperature of the heating cooker, selecting the cooking mode of high-frequency energy cooking, setting the output of high-frequency energy, and setting the heating time; Internal temperature,
It is comprised of a display tube 21 for informing the operator of heating time and the like. As mentioned above, the keyboard 2o contains keys for setting the internal temperature, keys for selecting the cooking mode, keys for setting the heating time, cooking mode that was incorrectly entered, internal temperature, heating time, etc. It consists of multiple keys for inputting commands and information necessary to operate the device to the microcontroller, such as a cancel key to cancel commands and information, and a start key to command cooking + 7) Iafi. , is connected to the microcontroller as described below.

Next, the circuit configuration of the heating cooker will be explained according to FIG. Reference numeral 22 in FIG. 3 is a power plug connected to a household power outlet, which supplies power to the cooking device. A fuse 23 is connected in series to this power supply plug to protect the device when an electrical component in the cooking device is short-circuited. Furthermore, a door switch 24 is connected in series to the fuse 23 for stopping power supply to the heater 1 and the high frequency oscillator 8 when the door 19 described above is opened or closed. Furthermore, a power relay 26 is connected in series to the door switch U for opening and closing the power supply line, which is controlled by a control circuit. The opening and closing of this power relay 25 is controlled by a microcomputer 26 as described later, and the heater 1 and high voltage transformer n are connected in parallel after the Mar relay 26, which supplies and stops power to the heater and high frequency oscillator 8. . Furthermore, the heater 1 has a heating chamber 3.
In order to keep the internal temperature constant, a control relay 28 that is controlled by a microcomputer and operates the heater 1 intermittently is connected in series. This control relay 28, when a control pulse is given to its coil by the microcomputer 26,
It becomes an on state, and becomes an off state when the supply of control pulses stops.

This on/off control is performed by the microcomputer 26 detecting a change in the characteristics of the heat sensitive element 17 provided near the heater 1. Further, a control relay B29 is connected to the high voltage transformer I to prevent the heater 1 and the high frequency oscillator 8 from being turned on at the same time. This control relay B
29+, is controlled by the microcomputer 2e, and when the operator selects heating cooking using the heater 1 using the keyboard 20, this control relay B29 is turned off, and when the operator selects cooking using high frequency energy, this control relay B29 is turned off. When the relay B2e is in the on state, power is supplied to the high voltage tractor 13 and paging 27. At this time, the control relay 28 is in an OFF state, and the power supply to the heater 1 is stopped. The power supplied to the high voltage transformer 27 via the control relay B29 is stepped up by the high voltage transformer 27 to become high voltage power, and further converted to high voltage double voltage DC voltage by a voltage doubler rectifier circuit including a high voltage diode 30 and a high voltage capacitor 31. be done. This high-voltage doubler voltage DC voltage is supplied to the high-frequency oscillator 8 , is converted into high-frequency energy of 2450 MH2 inside the high-frequency oscillator 8 , and is radiated from the antenna 9 of the high-frequency oscillator 8 . The high frequency energy radiated from the antenna 9 heats the object to be heated 7 through the process described above.

When the temperature of the heated object 7 heated by high-frequency energy reaches about 100° C., steam generation is observed. The steam passes through the exhaust guide 16 and is discharged to the outside of the machine together with the air sent to the heating chamber 3 from the above-mentioned proa fan 12. The exhaust guide 16 is provided with a humidity sensing element 18, which detects changes in the humidity within the heating chamber a due to the steam generated from the heated object 7 (page 14). This change in humidity within the heating chamber is finally transmitted to the microcomputer 26. The microcomputer 26 determines that the heating of the object 7 to be heated is completed, turns off the power relay 26, and finishes cooking.

As described above, key operations such as selecting the internal temperature of the heating chamber 3 and selecting the cooking mode by operating the keyboard 2o, the power relay 25, the control relays 28 and 29, the heat sensitive element, and the moisture sensitive element 18 The functions of the above are information to the microcomputer 26, or are driven by instructions from the microcomputer.

Here, the configuration of the microcomputer 26 and its control circuit will be explained with reference to FIG.

26 in the figure is a microcomputer, which is the center of control of the control circuit 32. This microcomputer 26 controls the external circuit, analyzes and calculates information obtained from the external circuit, and further controls the external circuit based on the results. Microcomputer 26
is an input terminal 33 for inputting the heating time of the keyboard 2o, setting information of the temperature inside the refrigerator, the state of the temperature inside the refrigerator of the heat-sensitive element 17, the state of humidity in the heating chamber s of the humidity-sensitive element 18, etc.
is provided. The information and instructions from the input terminal 33 are temporarily stored in an accumulator 34 for comparison with data stored in a ROM area, which will be described later, and for further transfer to the central processing unit. The microcomputer 2e also stores instructions, information, and data necessary for controlling the entire system (ROM area 36), and stores information and data transferred from the input terminal 33 (RAM area 26, Furthermore,
A central processing unit 37 performs analysis and calculation processing of various instructions, information, and data, and finally, based on the calculated data,
Output terminal 3 that outputs an output signal to control an external circuit
8.

The output terminal 38 of the microcomputer 26 supplies an output signal to the keyboard 2°, and when a desired key of the keyboard 20 is pressed by the operator, the output signal of the microcomputer 26 is input to the microcomputer 260 via the pressed key. The signal is transmitted to the terminal 33.

Signals transmitted to the input terminal 33 via the keys are transmitted to the microcomputer 26 as information on mode settings for the type of key pressed. The signal transmitted to the input terminal 33 is temporarily stored in the accumulator 34, and is compared with data in the ROM area 36, transferred to the RAM area 36, transferred to the central processing unit 37, and subjected to arithmetic processing. do.

Depending on the type of signal, the processed signal may be processed to drive an external circuit and then transmitted from the output terminal 38 of the microcomputer 26 to the external circuit. drive The processing of information regarding the keyboard has been described above, but the thermal element 17. Moisture sensing element 1
Information processing from No. 8 is also performed through exactly the same route. The information input to the input terminal 33 of the microcomputer 26 is as follows:
The keyboard 20 is used for drive signals output from the keyboard, the heat sensitive element 17, the humidity sensitive element 18, and the output terminal 38.
, power relay 25, control relay 26, control relay B
2a, etc., and is driven by information and instructions from the microcomputer 26.

Next, the operation in the above configuration will be explained 17
Page.

First, in the case where the heater 1 is used as a heat source, the temperature inside the refrigerator and the heating time are set by operating the keyboard 2o, and the information is transmitted to the microcomputer 26.

Based on the information, the microcomputer 26 opens and closes the power relay 25 according to the set heating time. In addition, the control relay 28 is turned on and off in accordance with the set temperature inside the refrigerator to maintain the temperature inside the refrigerator constant at a desired temperature for cooking.

Further, the output terminal 38 of the microcomputer 26 outputs an output signal to the display tube 21 to display the status of the internal temperature and heating time on the display tube. The content displayed on the display tube 21 is a display of the heating time set by the operator, or a display of the temperature inside the refrigerator. The above-mentioned control and display of the internal temperature is based on the function of the heat-sensitive element 1 connected to the output terminal 38 of the microcomputer 26. The heat sensitive element 1 is an element whose resistance value changes in response to changes in the temperature inside the refrigerator, and is connected in series with the dividing resistor 39. The output signal of the microcomputer 26 supplied to the heat-sensitive element 17 is divided by the heat-sensitive element 17 and the dividing resistor 18, and is then applied to the input terminal 33 of the microcomputer 26.
is transmitted as information on the temperature inside the refrigerator.

On the other hand, when operating as a heating cooker using high frequency energy as a heat source, a cooking mode is set by operating the keyboard 2o, and the information is transmitted to the microcomputer 26. Based on the information, the microcomputer 26 opens and closes the power relay 2ts+control+) relay 829. Also, depending on the set cooking mode, it starts taking in information from the moisture sensing element 18. Further, the output terminal 38 of the microcomputer 26 outputs an output signal to display the cooking mode on the display tube 21. As the cooking progresses and the heated object 7 reaches a temperature of about 100 degrees Celsius and steam is generated from the heated object, the humidity in the exhaust guide 16 decreases. The humidity sensing element 18 attached to the exhaust guide 16 detects this humidity change, and its own resistance value decreases. The output signal of the microcomputer 2e supplied to the humidity sensing element 18 is divided by a voltage dividing resistor 4o connected in series with the humidity sensing element 1B, and when the resistance value of the humidity sensing element 18 becomes low 1, the voltage is divided. The voltage from the microcomputer 26 increases and is transmitted to the input terminal 33 of the microcomputer 26. At this point, the microcomputer 26 determines that the cooking of the heated object 7 is completed, and the power relay 26 and control relay B29
Turn off.

As described above, the heating cooker of the present invention allows high-speed cooking using high-frequency energy and browning using the heater to be performed in the same heating chamber, and even when the heating cooker is used continuously, cooling is possible. By displaying and notifying the time, there is no cooking failure and it is extremely easy to use.

[Brief explanation of drawings]

Fig. 1 is a side cross-sectional view of a heating cooker which is an embodiment of the present invention, Fig. 2 is an external perspective view of the cooker, Fig. 3 is a control circuit diagram of the cooker, and Fig. 4 is the invention of the present invention. and a characteristic diagram showing the relationship between internal temperature and cooling time of a conventional heating cooker. 1... Heater, 3... Heating chamber, 7...
... Heated chamber, 8 ... High frequency oscillator, 1+
...Heat-sensitive element, 18... Moisture-sensitive element, 2
0...Keyboard, 21...Display L2
6...Microcomputer, 32...
・Name of patent attorney Toshio Nakao and one other person

Claims (1)

[Claims] (1) A heat-sensitive element is provided to detect the temperature inside the heating chamber,
The data of the initial chamber temperature detected by this heat-sensitive element and the data of the desired chamber temperature input via the keyboard are stored in the microcomputer, and the thermal time constant necessary for cooling the heating chamber is stored in the microcomputer. The cooking device is configured to calculate a cooling time in the heating chamber from the two data of the initial chamber temperature and the desired chamber temperature and the thermal time constant, and display the cooling time on a display tube. 2) The cooking device according to claim 1, wherein the cooking device is configured to count down the cooling time displayed on the display tube in units of time. (3) The microcomputer stores data on the desired internal temperature of the refrigerator 2, which is determined by the initial internal temperature detected by the heat-sensitive element and the selection of the cooking mode using the humidity sensor input via the keyboard. By storing the thermal time constant necessary for cooling the heating chamber in the micro combinator, the cooling time in the heating chamber is calculated from those two data and the thermal time constant, and the cooling time is displayed on the display. A heating cooker according to claim 1, having a configuration shown in .