JPS6347968B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic heating device that uses sensors to automate heating.

BACKGROUND ART In recent years, significant advances in semiconductor technology have led to the realization of heating devices that are equipped with various sensors, detect the heating state of an object to be heated, and automatically terminate heating.

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 heated with fewer failures.

As such prior art, there is
There is a publication number 134951. This detects the change in humidity generated from the object to be heated, and determines the point at which steam is generated when it reaches a certain set value. 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.

Problems to be Solved by the Invention However, this prior art had the following difficulties.

That is, if the amount of the object to be heated differs greatly, the amount of water vapor, alcohol, carbon dioxide, etc. generated from the object to be heated will also vary, making it difficult to obtain sufficient sensitivity especially when the amount is small.

FIG. 3 is an example clearly showing such a situation. Conventionally, when a menu is selected from a keyboard, a certain threshold value a corresponding to the object to be heated is preset in the control section. Since this value was constant regardless of the quantity, as shown in the figure, even if 1 provides reliable sensitivity when the heated object is large, 2 has little margin for the total amount of change when it is small. , there is a high risk of sensor failure. However, if a is set to a small value in consideration of the small amount 2, sensor insensitivity can be saved, but in the case of a large amount 2, an early minute amount of steam due to partial evaporation is detected, resulting in a premature cut-off phenomenon.

Means for Solving the Problems In order to solve the above problems, the present invention includes a plurality of auto keys provided on an operation panel etc. that instructs to automatically end heating depending on the type of the object to be heated, etc. It consists of a sensor that detects water vapor, alcohol, carbon dioxide gas, etc. emitted by the object to be heated, and a control section that controls power supply to the heating source, and the control section further includes a counter that counts the elapsed time from the start of heating. means for detecting water vapor or the like emitted by the object to be heated by the sensor; comparison means for comparing the output of the detection means with a certain reference level; It has threshold setting means for giving an initial value of the reference level, and threshold updating means for updating this threshold with the passage of time.

Effect: In the automatic heating device equipped with the sensor of the present invention, when the comparing means detects that the output of the detecting means exceeds the threshold that is updated over time, the counter means performs counting. The heating source is configured to control the point in time when the power supply to the heating source is terminated based on the elapse of time.

Embodiment Hereinafter, an automatic heating device equipped with a sensor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of the main body of the automatic heating device according to the present invention. A door body 2 is attached to the front surface of the main body 1 so as to be openable and closable, and an operation panel 3 is arranged. On the operation panel 3, there are provided at least a keyboard 4 for selecting a heating sequence depending on the object to be heated, and a display section 5 for making various notifications.

FIG. 2 shows a control block diagram of such a heating device. A heated object 7 is placed in the heating chamber 6, and a magnetron 8 is connected as a heating source. Power supply to the magnetron 8 is controlled by a control unit 9.
The detailed configuration of the control section 9 will be described later. 10
is a humidity sensor or a gas sensor, and the water vapor from the heated object 7 exhausted by the fan 11,
Gas 12 such as alcohol and carbon dioxide gas is detected. Based on the detected data, the control unit 9 controls the power supply to the magnetron 8, displays various data on the display unit 5, and outputs the speaker or buzzer 13.
Depending on the system, various notification warnings can be issued using synthesized voices or buzzer sounds.

Now, how the control section 9 operates in this configuration will be described below.

FIG. 4 is a graph showing a method for detecting steam generation points according to the present invention. The control unit 9 changes the threshold value a over time. Therefore, in the case of heating a large amount of material to be heated, the threshold value _a1 is set large, and the early minute amount of steam due to partial evaporation is ignored, so the premature cut-off phenomenon does not occur. . On the other hand, in the case of 2, in which a small amount of the object to be heated is heated, the threshold value a ₂ is still small, so steam can be detected with high sensitivity and sensor insensibility can be prevented.

FIG. 5 is a graph showing changes in the threshold value a over time. When the type of object to be heated is first selected using a key on the keyboard 4, the control section 9 sets an initial value α ₀ suitable for that key. When heating is started, this threshold value a is updated at intervals of time t. Of course, the time t and the amount of change Δa need not be linear as in the key A example. Of course, it is also possible to make non-linear changes as shown in key B based on experiments. The amount dependence could be significantly improved by simply switching to at least two stages.

Note that the threshold value a may be an absolute value as in this embodiment, or may be a relative value such as the voltage ratio between points _P1 and _P2 .

Both Figures 3 and 4 showed the change in relative humidity during heating, which shows that it decreases for a while after heating starts, and as the temperature of the heated object rises and begins to emit water vapor, the relative humidity also increases. . In the case of carbon dioxide gas or alcohol, the relative humidity does not normally drop temporarily after heating starts, but rises as heating progresses. However, when heating is repeated, the gas generated from the previous heating increases. Since it remains in the heating chamber, it temporarily decreases or recovers like relative humidity. Therefore, when detecting carbon dioxide gas or alcohol, the minimum point P ₁ is used as in this example.
An effective method is to detect this and calculate the increase from there.

Now, how to realize the above control method, the specific configuration of the control section will be described in detail below. FIG. 6 is a block diagram showing the functional configuration of the control section 9. As shown in FIG. The analog quantity detected by the sensor 10 is converted into a digital quantity by the A/D converter 14, which is a detection means, and is inputted to a _V1 detector 15 and a level comparator 16, which is a comparison means. The V ₁ detector 15 is a block that detects the level of the P ₁ point, and stores this in the V ₁ holding register 17 . Specifically, V ₁ detector 15 is V ₁ register 1
First read the value of 7 and compare it with the new data.
Controls updating of the _V1 value to the _V1 holding register 17. _P1
The advantages of point detection have already been discussed.

On the other hand, the threshold value a _o which is the reference level of the comparison means is the initial value a ₀ corresponding to the auto key pressed from the keyboard 4, and the a selector 1 which is the threshold value updating means.
8, a register 19 serving as a threshold value setting means.
The level comparator 16 is then preset. This threshold a _o is updated by the a selector 18, which is threshold updating means, as shown in FIG. 5, in response to the timing signal T output from the up counter 20, which is countering means.

The level comparator 16 compares the sensor information input from the A/D converter with the above-mentioned _V1 value,
It is determined whether the threshold value _ao inputted from the a selector 18 has been exceeded. In other words, _two points P are detected. When the _P2 point is reached, the EDT signal is output.

When the HDT signal is output, clock counting by the up counter 20, which is a counter means, stops. And counted by up counter 2
T ₁ hour is input to multiplier 21 and additional heat time
R _n ·T ₁ is calculated and preset into the down counter 22. The constant R _n is a value corresponding to the menu selected by the keyboard 4, which is set by the R selector 2.
3 is read out from the R register 24 and input to the multiplier 21.

On the other hand, power supply to the magnetron 8 is started by the flip-flop 25 immediately after the start key is pressed. 26 is a drive circuit that operates the magnetron 8. The flip-flop 25 shifts to overheating mode and is reset by the ZERO signal when the decoder 27 detects that the contents of the down counter 22 have become zero, that is, when R _n ·T ₁ hour has passed from point P ₂ . to finish heating.

As described above, the present invention can be realized by the control section shown in FIG. In addition, each functional block in Figure 6 can be replaced with software logic based on a program.
Naturally, most of this can be realized by a storage logic controller such as a microcomputer.

Effects of the Invention As explained above, according to the present invention, when a key is pressed to command automatic heating of a certain object to be heated, an initial detection threshold suitable for the object to be heated is set. Therefore, if the amount of the object to be heated is small, the heating ends at a small detection threshold value, and if the amount of the object to be heated is large, the detection threshold value is automatically set to a large value. Therefore, even if the quantity changes, stable automatic heating without premature cutting or overheating can be achieved. In addition, since a threshold value appropriate to the amount is selected, it is possible to avoid a dangerous situation in which the amount of steam or gas generated does not reach the threshold value and the sensor is unable to finish heating forever.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main body of the automatic heating device according to the present invention, Fig. 2 is a block diagram of the same configuration, Fig. 3 is a diagram showing the conventional humidity detection method, and Fig. 4 is a diagram showing the humidity detection method according to the present invention. FIG. 5 is a diagram showing a method of controlling the threshold value, and FIG. 6 is a functional block diagram of the control section. 4...Keyboard, 6...Heating chamber, 7...Heated object, 8...Heat source, 9...Control unit, 10...Sensor, 14...Detection means, 16...Comparison means, 1
8... Threshold updating means, 19... Threshold setting means, 20... Counter means.

Claims (1)

[Claims] 1. A heating chamber in which the object to be heated is placed, a heating source connected to this heating chamber, and a plurality of devices installed on the operation panel etc. that instruct the heating to be automatically terminated depending on the type of the object to be heated, etc. It consists of an auto key, a sensor that detects water vapor, alcohol, carbon dioxide, etc. emitted by the object to be heated, and a control section that controls the power supply to the heating source, and the control section controls the elapsed time from the start of heating. a counter means for counting, a detection means for detecting water vapor etc. emitted by the object to be heated by the sensor, a comparison means for comparing the output of the detection means with a certain reference level, and a comparison means for comparing the output of the detection means with a certain reference level in response to the pressing of the auto key. The controller includes threshold setting means for providing an initial value of the reference level to the means, and threshold updating means for updating the threshold value over time, and the control section uses the comparing means to determine the value of the detecting means. When detecting that the output exceeds the temporally updated threshold, determining a point in time to end power supply to the heating source based on the elapse of time counted by the counter means; An automatic heating device comprising a sensor configured to power said heating source up to that point.