JPS6347969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cooking device that controls the operation of a heating source by detecting the cooking state of an object to be heated using a sensor.

Conventional configurations and their problems In recent years, significant advances in semiconductor technology have enabled control circuits to become more sophisticated, more compact due to higher integration, and lowered in price due to mass production. has come to be widely used.

Intelligent technology based on electronic control has rapidly progressed in various heating devices such as electric ovens, microwave ovens, gas ovens, and combination cookers. A particularly noticeable trend in heating devices is that automatic heating devices, which detect the heating state of objects to be heated using various sensors and automatically control heating, have rapidly become popular.

This system uses a sensor to automatically terminate heating without the user having to manually set the heating time, output, heating temperature, etc., as in the case of conventional methods. Microwave ovens and other devices that require consideration of temperature and other factors have become much easier to operate and can be used to cook food with fewer mistakes.

As such prior art, there is
There is number 134951. This detects changes in humidity based on the steam generated from the heated object, and determines the point in time when the humidity reaches a certain set value as the steam generation point. The total heating time is the sum of the heating time T ₁ to reach that point and the product RT ₁ of a separately determined coefficient R specific to the heated object.

This is an example of automatic heating control using a so-called humidity sensor, but it is also an extremely effective control method for a so-called gas sensor that reacts with steam, alcohol, and carbon dioxide.

However, this method also had the following problems.

In other words, since the sensor element is exposed to oil vapor, soy sauce, and other organic vapors, and dew condensation occurs, the moisture-sensitive surface area of the sensor element decreases due to contamination of the crystal particles of the sensor element, and the sensitivity to humidity becomes dull.
Therefore, conventionally, the sensor element was connected at the same time as cooking started.
A cleaning operation was carried out in which dirt adhering to the sensor element was decomposed into CO ₂ and H ₂ O by heating it to over 400°C. Therefore, a rise time for the sensor element to reach 400° C. and a fall time for the sensor element to cool to the initial temperature are required.

By the way, relative humidity has a property that even if the same amount of water vapor is contained in the air, it changes depending on the temperature. For example, if there is air containing 10g/Kg of water vapor, if the temperature is 20℃, the relative humidity will be 70%, but if the temperature rises to 40℃, the relative humidity will be 20%.
%. This shows that temperature is deeply involved when trying to detect relative humidity. In order to accurately detect relative humidity from this point of view, the temperature of the sensor element itself must be sufficiently cooled down to the initial temperature. After the temperature has cooled down sufficiently, start power supply to the heating source, calculate the time T ₁ until the humidity change from this point reaches the predetermined set value, and then calculate the time T 1 required for the change in humidity to reach the predetermined set value. Additional heating was performed by the product RT ₁ to make up the total heating time.

As described above, in the conventional method, since the sensor element is cleaned immediately after the start of cooking, it is necessary to wait for power to be supplied to the heating source, which has the disadvantage that it takes a long time to complete cooking.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and aims to shorten the cooking time by eliminating the need to clean the sensor element immediately after the start of cooking.Moreover, by using the sensor element that is cleaned at the time of cooking, it is possible to adjust the cooking time according to the menu. The object of the present invention is to provide a heating cooker that realizes automatic heating.

Structure of the Invention In order to achieve the above object, the heating cooker of the present invention cleans the sensor that detects steam or gas generated from the object to be heated and controls the operation of the heating source, instead of cleaning it based on the time when cooking starts. , the cleaning is performed after a predetermined period of time, and the sensor element is normally in a state where it can detect the generation of steam or gas when cooking starts, so the cleaning time of the sensor element can be omitted and the cooking time can be shortened. This has the effect of making it possible.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 4.

In FIG. 1, reference numeral 1 denotes a heating chamber that houses an object 2 to be heated, and the object 2 in the heating chamber 1 is dielectrically heated by high frequency energy oscillated from a magnetron 3, which is a heating source. A fan motor 4 cools the magnetron 3 and the like and blows ventilation air 7 into the heating chamber 1 through an air duct 5 and an air outlet 6. Exhaust air 9 containing water vapor 8 emitted from the object to be heated 2 is discharged into an exhaust duct 11 through an exhaust port 10. Reference numeral 12 denotes a relative humidity detection sensor (hereinafter simply referred to as a sensor), which controls the operation of the magnetron 3 in response to the relative humidity of the exhaust air 9.

In FIG. 2, 13 is a sensor element constituting the sensor 12, and 14 is a coil heater provided near the periphery of the sensor element 13 to clean the sensor element 13. 15 is a support portion that supports the coil heater 14 and the sensor element 13.

In FIG. 3, reference numeral 16 denotes a power relay that controls power supply to the magnetron 3, and is driven by an output signal from a total heating time control section 17 that controls heating time. 18 is a cleaning completion detection section of the sensor 12, which processes the signal from the sensor element 13;
After cleaning is completed and humidity is detected, R-
A cleaning end signal (Se) is output to the flip-flop 19, and a humidity detection signal (Sh) is output to the total heating time control circuit 17. Reference numeral 20 denotes an input detection unit that detects the input of commercial power, and outputs a pulse when the power is connected. Reference numeral 21 denotes a time measuring section, which outputs pulses at predetermined time intervals when the power is input. Outputs from the input detection section 20 and time measurement section 21 are input to an OR circuit 22, and the output thereof is input to an R-S flip-flop 19.
23 is a power supply unit for cleaning. A power relay 24 controls power supply to the coil heater 14 and is driven by a signal from the R-S flip-flop 19.

The operation of the above configuration will be explained below.
First, when the input of the heating cooker is connected to a commercial power source, a pulse is generated from the input detection section 20, and the time measurement section 21 starts the time measurement operation.
A signal is output to the R-S flip-flop 19, and the R
The output signal from the -S flip-flop 19 drives the power relay 24, and the coil heater 14 cleans the sensor element 13. When the cleaning of the sensor element 13 is completed, the Se signal is inputted from the cleaning end detection section 18 to the reset side of the R-S flip-flop 19, and the R-S flip-flop 19 is reset.
The output of the S flip-flop 19 is set to 0 to turn off the power relay 24.

Note that the time measurement section 21 starts measurement based on the input detection signal of the power supply, generates a pulse at predetermined time intervals, and outputs the signal to the set side of the R-S flip-flop 19, in the same manner as when the input power supply is connected. The cleaning operation is performed.

FIG. 4 shows another embodiment in which a time measuring section 25 is provided in place of the time measuring section 21 shown in FIG. A pulse is output to the S flip-flop 19, and the output signal from the R-S flip-flop 19 drives the power relay 24, and the coil heater 14 cleans the sensor element 13. Then, a pulse is output from the time measuring section 25 to the R-S flip-flop 19 at a preprogrammed time, and cleaning of the sensor element 13 is performed at a predetermined time in the same way as when the commercial power source is connected.

As described above, according to the heating cooker of the present embodiment, since the sensor element 13 is cleaned by the coil heater 14 at predetermined intervals or predetermined times, cleaning is not necessary during cooking unless a cooking start operation is performed during cleaning. There is no need for cooking, and the cooking time can be reduced accordingly.

In addition, since the time measurement unit 21 operates according to the output signal from the input detection unit 20 and starts time measurement,
Cleaning by detecting input power and cleaning by time measurement are always performed at a predetermined time interval, so cleaning is not performed continuously by the output signals from the input detection section 20 and the time measurement section 21. Overheating of the sensor element 13 can be prevented.

Furthermore, be sure to clean the sensor element 13 before preparation time at breakfast and lunch, when it is frequently used.
Since the cleaning can be configured so as not to be performed at night when the cooking frequency is low, the sensitivity of the sensor element 13 is always high, and good cooking can be performed according to the cooking menu.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) By cleaning the sensor element at predetermined intervals, it is possible to keep the sensor clean at all times, and the heating operation can be started at the same time as cooking starts, reducing cooking time and cleaning the sensor element. It is possible to achieve a longer lifespan.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a heating cooker according to an embodiment of the present invention, Fig. 2 is a perspective view showing the sensor of Fig. 1, Fig. 3 is a control circuit diagram of the same, and Fig. 4 is a diagram of the sensor of the present invention. It is a control circuit diagram of the heating cooker which shows another Example. 1... Heating chamber, 3... Magnetron (heating source),
13... Sensor element, 14... Coil heater (cleaning means), 17... Total heating time control section (control section), 21... Time measuring section (control section).

Claims (1)

[Claims] 1. A heating chamber that accommodates an object to be heated, a heating source that heats the object that is housed in this heating chamber, a control unit that controls power supply to this heating source, and steam or gas generated within the heating chamber. a sensor consisting of a sensor element for detecting a sensor element and a means for cleaning the sensor element, and a control section for measuring an operation time of the cleaning means and controlling the cleaning operation, the cleaning means being controlled by the control section. A heating cooker configured to start cleaning when a predetermined time has elapsed after cleaning.