JPS6121327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called automatic cooking device that detects gas, steam, etc. generated from an object to be cooked and automatically shuts off the power to a heating device when the cooking of the object is completed. The purpose of the present invention is to provide a heating device that is easy to use.

Recently, this type of automatic cooker has been released,
If you inadvertently open the door during cooking or season the food, odors, smoke, gas, and steam from the heating process will escape outside the heating chamber, so it is best to stop the heating device when you open the door. It was getting worse. As a result, once the heated object has reached this state, if it is heated again automatically, it will be overheated, and even if it is heated with a manual timer, the heating time will be short until the door is opened. Not knowing this led to either overcooking or undercooking, which became extremely troublesome.

The present invention solves the above-mentioned conventional drawbacks, and will be explained below with reference to the drawings.

FIG. 1 is a side cross-sectional view of a so-called oven range that integrates high-frequency heating and heater heating as a typical example of a heating cooker. A door 3 and a heating chamber 2 are installed in the front opening of the heating chamber 2.
There is a rotary mounting table 6 supported by rollers 4 and rotated by a motor 5 at the bottom. On the rotary mounting table 6 is a wire mesh 8 on which the object to be heated 7 is placed. Heating chamber 2
A heater device 10 with a reflector 9 is attached to the front of the upper part, and a power supply port 11 for high-frequency heating is formed in the center of the upper part, and a power supply port 11 for high-frequency heating is connected to a high-frequency generator (not shown) through a waveguide 12. High frequency is supplied to the heating chamber 2. Note that 13 is a partition plate. A punching hole 14 is provided in the upper part of the rear wall of the heating chamber, and steam gas generated in the heating chamber 2 is exhausted to the outside via an exhaust guide 15. A spacer 1 is installed to prevent the exhaust guide 15 from being blocked by a wall or the like when a heating device is installed in a portion facing the exhaust guide 15.
I am wearing 6. A gas sensor 17 for detecting gas discharged from the heating chamber 2 is installed in the exhaust guide 15 .

FIG. 2 is a diagram showing a change in the resistance value of the gas sensor during cooking. There are various types of gas sensors, but here we will explain an example using an N-type semiconductor whose resistance value decreases by adsorbing gas. In FIG. 2a, up to t ₁ is the heating cleaning time for purifying the gas sensor, and the resistance value changes from R ₁ to R ₂ due to so-called semiconductor characteristics. The period from t ₁ to t ₂ is a cooling period in which the sensor, which has become hot due to heating cleaning, is returned to room temperature. t ₂ - _{t 3} and t ₄ - _{t 5} are heating times as shown in figure b, and during this period t ₃ - t ₄ indicate the time during which the door was opened carelessly. Here, if we look at how the resistance value of the sensor changes during the time t ₃ - _{t 4} of door opening, it differs depending on the type of sensor. That is, curve 1 is a gas sensor used at room temperature, and curve 2 is a type of gas sensor that constantly maintains the sensor temperature at a high temperature. With high-temperature type sensors, when the gas concentration drops when the door is opened, it is oxidized by heat.
The resistance value returns to its original value by αR. If you close the door and continue heating again, the resistance value will continue to decrease and the reference value stored in the heating device, for example curve 1, will continue to decrease.
Then, when R ₁ /3 is reached, the power to the heating device is turned off and cooking is completed.

Here, in the conventional heating cooker, cooking was stopped at the time t ₃ when the door was opened during heating, but in the present invention, cooking is continued if the time t ₃ - _{t 4} is within a certain period of time. . In other words, the heating device starts operating from time t ₄ when the door is closed and the button on the cooking switch is pressed, and with a normal temperature type sensor, the reference value reaches R ₁ /3 as shown in curve 1, and the heating device turns off at time t ₅ . .
On the other hand, for high temperature type sensors, the standard value is R ₁ /3+
Since only αR is corrected, the point at which this value is reached
At _t5 , the heating device is shut off and cooking is complete. Furthermore, αR
is determined by the sensor and heating device, and if the angle at which it returns to its original state is also θ, then αR=(t ₄ −t ₃ ) tan.
Note that the heating device is turned off when t ₃ −t ₄ becomes a certain time or more. According to the experimental results, although it varies depending on the type of heating device, the type of outlet heated object, the heat capacity, etc., it has become clear that if it is about 1/20 of the total heating time, it will not have much effect on the cooking results. In other words, for salt-grilled mackerel, grilled chicken thighs, etc., it takes about 10 to 15 minutes with a normal heating device, but with this, if you open the door for about 30 to 45 seconds, the temperature of the heated item will drop in the early stages of cooking. When the temperature has completely decreased, the browned area becomes a little thinner, and after the temperature inside the heating chamber reaches a sufficiently high temperature, the heating progresses with the heat accumulated in the heating chamber, and the browned area becomes a little thicker.

Next, a circuit for operating the heating pattern described above will be explained with reference to the block diagram of FIG. When the door is closed, the door switch 18 is turned on, and when a cooking button (not shown) is pressed, a signal is input to the operation input circuit 19, the refresh circuit 20 is activated, and cleaning of the sensor 17 begins. When cleaning is completed (t ₂ o'clock in Figure 2)
The resistance value of the sensor 17 is converted into a voltage by the voltage converter 21 and stored in a part of the determiner 22, and the driver 23 operates the thyristor 24 to energize the heating device 10. If you continue to cook without opening the door, the sensor resistance will change as shown in curve 3 in Figure 2.
The reference value 25 (initial resistance R ₁
When the driver 2 reaches 1/3), the judge 22
3 to turn off the heating device 10 using the thyristor 24. On the other hand, if the time that the door is open during cooking is measured using 26, and the door is closed again and the cooking button is pressed, the judgment device 22 will judge based on the signals from the time measuring device 26 and the operation input circuit 19, and the time will be within a certain amount of time. If so, the heating device 10 is operated, and if the temperature exceeds this, a signal is sent to the operating section to inform that cooking is not possible. Note that in the case of a high temperature type sensor, correction is required as shown in curve 2 in FIG. 2, and a corrector 27 corrects the reference value 25 at the end of cooking. Further, 28 is a power supply circuit for driving each of the above-mentioned circuits.

In the above description, a case has been described in which the gas generated during browning is detected, but it goes without saying that the humidity sensor may detect steam generated from the object to be heated instead of the gas. The same applies to the method of cutting off the power to the heating device after a certain period of time after detecting steam with a sensor.

As is clear from the above explanation, automatic heating devices measure the time the door is open, continue cooking within a certain amount of time, and shut off the power to the heating device when a certain amount of time has elapsed. Therefore, even if you accidentally open the door during cooking, you can immediately press the adjustment button to continue automatic cooking, and you can also add flavor or check the doneness during cooking, which is extremely convenient.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a heating cooker showing an embodiment of the present invention, Fig. 2 is a diagram showing changes in resistance values of sensors in the main parts, and Fig. 3 is a block diagram showing the control system of the cooker. be. 2... Heating chamber, 3... Door, 10... Heater device, 11... Power supply port, 15... Exhaust guide, 17
...Sensor.

Claims (1)

[Scope of Claims] 1. A heating chamber that stores an object to be heated, a heating device that heats the object to be heated in the heating chamber, a door that opens and closes an opening of the heating chamber, and steam generated from the object to be heated; A detection element that detects gas, etc., a device that shuts off the power to the heating device when the amount detected by the detection element reaches a certain level or a certain period of time after reaching a certain level, and a measuring device that measures the heating time. and a device that measures the time the door is open when the door is opened while heating the object to be heated, and continues the cooking operation if the door opening time is within a preset certain time, A cooking device characterized in that the power to the heating device is cut off when the door is opened for a certain period of time or more. 2. The cooking device according to claim 1, further comprising a circuit that measures the opening time of the door and changes in the amount detected by the detection element to correct the heating time.