JPH0243093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a cooking appliance equipped with a gas sensor.

(Prior Art) Conventionally, there is a cooking appliance of this type, such as a microwave oven, as shown in FIG. In FIG. 1, a heating chamber 1 is provided with a rotating shelf 2 for placing objects to be heated, that is, food to be cooked, and a high frequency generator such as a magnetron 3.
An antenna 3a is introduced. Furthermore, heating chamber 1
A gas sensor 4 is disposed near the ceiling surface of the heating chamber 1, and various gases (hereinafter referred to as gases) in the heating chamber 1 are detected by the gas sensor 4. After the output of the gas sensor 4 is signal-processed by the gas concentration detection circuit 5, it is supplied to the microcomputer 6, which is the main control section. The microcomputer 6 controls the power supply from the power source 8 to the magnetron 3 by controlling the relay 7 on and off in accordance with the gas concentration based on the output of the gas concentration detection circuit 5.

Therefore, when cooking is started with the food to be cooked 9 placed on the shelf 2, gas is generated from the food 9 as the cooking progresses, and the gas is detected by the gas sensor 4. Then, the microcomputer 6
The output of the magnetron 3 is controlled according to the gas concentration in the heating chamber 1 based on the output of the sensor circuit 5. In other words, as shown in Figure 2, the gas concentration is at the set value.
The magnetron 3 is operated at full power for the ta time until reaching D ₀ , and when the gas concentration reaches the set value D ₀ , the output of the magnetron 3 is reduced to about half to perform additional heating, and this additional heating is continued for the βta time. It is something to do.

(Problems to be Solved by the Invention) However, in such a microwave oven, the amount of gas generated varies depending on the amount of food 9, which causes the following problems.
For example, when heating alcohol (kotup sake) as shown in Figure 3, the gas concentration for one kottupu sake changes as follows, and the main heating is performed at point P (time tp) where the gas concentration reaches the set value _D1 . is completed, after which additional heating for βtp time is performed. On the other hand, when there are 2 to 3 pieces of Kotsupu sake, the gas concentration changes as follows.
The main heating ends at point Q (time tq) when the gas concentration reaches the set value _D1 , and then additional heating is performed for a time βtq. In this way, the relationship between the total heating time Tp for one piece of Kotup sake and the total heating time TQ for two to three pieces of Kotup sake is Tp = tp + βtp > TQ = tq + βtq
Therefore, if there are only 2 or 3 pieces of koppu sake, the temperature will be low. According to actual experiments, Kotsupu sake has 4
The temperature when one piece is about 10% higher than the temperature when one piece
It will be about ℃ lower.

Furthermore, the electric field distribution inside the heating chamber 1 is as shown in Figure 4, so when root vegetables are wrapped and cooked, only a portion of them is heated and gas is generated. There is a problem in that the quality of the cooking deteriorates. In other words, as shown in Figure 3, the main heating time for one root vegetable is tr, whereas the main heating time for four root vegetables is only ts, which is slightly longer than tr, and the finished product is This will make a big difference in temperature.

This invention was made in view of the above-mentioned circumstances, and its purpose is to eliminate unevenness in the finished temperature caused by differences in the weight of objects to be heated, and to improve the reliability of gas detection cooking. The purpose of this invention is to provide an excellent cooking device that can serve the purpose of cooking.

[Structure of the Invention] (Means for Solving the Problems) The cooking appliance of the present invention includes a heating chamber, a high frequency generator that supplies high frequency waves into the heating chamber, a gas sensor that detects gas in the heating chamber, and a gas sensor that detects gas in the heating chamber. a first control means for controlling the operation of the high frequency generator by comparing the detection result of the gas sensor with a set value; a weight sensor for detecting the weight of the object to be heated in the heating chamber; A second method for correcting the detection result of the gas sensor so as to eliminate unevenness in finished temperature caused by differences in the weight of the heated object.
The device is equipped with a control means.

(Function) During cooking, the weight of the object to be heated in the heating chamber is detected by a weight sensor, and depending on the detected weight,
The second control means corrects the detection result of the gas sensor so as to eliminate unevenness in finished temperature caused by differences in the weight of the heated object. Thereby, it is possible to eliminate unevenness in the finished temperature caused by differences in the weight of the objects to be heated.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In this case, the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 5, weight sensors 10a and 10b are provided between the bottom surface of the heating chamber 1 and the back surface of the rotary shelf 2. As shown in FIG. These weight sensors 10a and 10b are connected to the food 9
It is a pressure sensor that converts a mechanical quantity (strain) based on the weight of the body into an electrical quantity (resistance), and uses the so-called piezo effect. However, the weight sensor 10a,
The output of 10b is subjected to signal processing by the weight detection circuit 11, and is supplied to the microcomputer 6. The microcomputer 6 includes a first control means that controls the operation of the magnetron 3 by controlling a relay 7 on and off based on a comparison between the detection result of the gas sensor 4, that is, the gas concentration detected by the gas concentration detection circuit 5, and a set value; It functions as a second control means for correcting the gas concentration detected by the gas concentration detection circuit 5 in accordance with the detected weight of the food 9 based on the detection results of the weight sensors 10a and 10b, that is, the output of the weight detection circuit 11.

Here, FIG. 6 specifically shows the main part of FIG. 5. That is, a DC voltage V is applied to the gas sensor 4 via resistors 21 and 22 in series. Then, the voltage obtained at the connection point between the gas sensor 4 and the resistor 22 is supplied to the gas concentration detection circuit 5 as the output of the gas sensor 4. The gas concentration detection circuit 5 includes a feedback amplifier circuit 23 and an analog-digital converter 24 that converts the output of the amplifier circuit 23 into a digital signal. In this case, the amplifier circuit 23 includes a plurality of feedback resistors 23a, 23b,
23c, and switching elements 25a, 25b, and 25c that respond to commands from the microcomputer 6 are connected in series to these feedback resistor circuits, respectively. In other words, the amplification degree of the amplifier circuit 23 is changed according to the command from the microcomputer 6. On the other hand, weight sensor 10
a and 10b constitute a bridge circuit together with resistors 31 and 32, and a voltage from a DC power supply 33 is applied to this bridge circuit. The voltages obtained at both output ends of this bridge circuit are supplied to the weight detection circuit 11, respectively. Weight detection circuit 11
is a differential amplifier circuit 41 to which voltages at both output terminals of the bridge circuit are respectively input;
The feedback amplifier circuit 42 amplifies the output of the amplifier circuit 42, and the analog-to-digital converter 43 converts the output of the amplifier circuit 42 into a digital signal.

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

Now, when the food 9 to be cooked is placed on the shelf 2, the weight of the food 9 is detected by the weight sensors 10a and 10b, and this detection signal is processed by the weight detection circuit 11 and supplied to the microcomputer 6.
When cooking starts, gas is generated from the food 9 as the cooking progresses, which is detected by the gas sensor 4. This detection signal is processed by the gas concentration detection circuit 5 and sent to the microcomputer 6. Supplied. At this time, the microcomputer 6
switches the amplification degree of the amplifier circuit 23 in the gas concentration detection circuit 5 according to the weight of the food 9, thereby correcting the detected gas concentration, and controls the output of the magnetron 3 according to the corrected gas concentration.

That is, the weight of one bottle of sake is taken as the standard weight, and as shown in FIG. 7, if the weight is the standard weight, the magnetron 3 is controlled according to the actual change in gas concentration. In other words, the gas concentration is set to
Main heating ends at point P (time tp), which is D ₁ , and then additional heating is performed for βtp time. Also,
In the case of two or three pieces of sake that are heavier than the standard weight, the amplification degree of the amplifier circuit 23 is reduced and the actual gas concentration change is corrected to ', and the magnetron 3 is controlled according to this corrected gas concentration change'. .
That is, the main heating ends at point Q' (time tq') where the correction gas concentration reaches the set value _D1 , and then additional heating is performed for time βtq'. Therefore, the relationship between the total heating time Tp for one Kotsupu sake and the total heating time TQ for two to three Kotsupu sake is Tp = tp + βtp < TQ
= tq'+βtq', and the temperature in the case of 2 to 3 pieces of kotsupu sake can be made approximately the same as in the case of 1 piece of kotsupu sake.

In this way, the weight of the food to be cooked is detected, the detected gas concentration is corrected according to the detected weight, and the operation of the magnetron 3 is controlled according to the corrected gas concentration. It is possible to eliminate unevenness in the finished temperature caused by differences in temperature, and it is possible to improve the reliability of gas detection cooking.

In the above embodiment, the detected gas concentration was corrected according to the detected weight, and the operation of the magnetron 3 was controlled according to the corrected gas concentration. As another method, the set value for the detected gas concentration may be changed depending on the detected weight. That is, as shown in Figure 8, when the food to be cooked is 2 to 3 pieces of sake that are heavier than the standard weight, the set value is increased from D ₁ to Da, and main heating is performed until the detected gas concentration reaches Da. It is something. Another method is to change the detection sensitivity of the gas sensor 4 depending on the detected weight.

Further, in the above embodiment, the main heating time is indirectly corrected by correcting the detected gas concentration, but the additional heating time may be corrected. Further, although the case where additional heating is performed after main heating has been described, the same can be applied to the case where only main heating is performed.

In addition, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without changing the gist.

[Effects of the Invention] As described above, according to the present invention, there is provided a heating chamber, a high frequency generator that supplies high frequency waves into the heating chamber, a gas sensor that detects gas in the heating chamber, and a detection result of the gas sensor. a first control means for controlling the operation of the high frequency generator by comparison with a set value; a weight sensor for detecting the weight of the object to be heated in the heating chamber; and a detection result of the gas sensor according to the detection result of the weight sensor. and a second control means for correcting the result to eliminate unevenness in the finished temperature caused by differences in the weight of the heated object.
It is possible to provide an excellent cooking device that can eliminate unevenness in finished temperature caused by differences in the weight of objects to be heated, and can improve reliability in gas detection cooking.

[Brief explanation of drawings]

Figure 1 is a conventional configuration diagram, Figures 2 and 3 are diagrams for explaining the operation of Figure 1, and Figure 4 is a diagram for explaining the operation of Figure 1.
5 is a diagram showing the electric field distribution state in the heating chamber, FIG. 5 is a configuration diagram showing an embodiment of the present invention, and FIG.
FIG. 7 is a diagram for explaining the operation of the same embodiment, and FIG. 8 is a diagram for explaining the operation of another embodiment of the present invention. 1... Heating chamber, 2... Rotating shelf, 3... High frequency generator (magnetron), 4... Gas sensor, 6
...Microcomputer (first control means, second control means)
control means), 10... weight sensor.

Claims (1)

[Claims] 1. A heating chamber, a high-frequency generator that supplies high-frequency waves into the heating chamber, a gas sensor that detects gas in the heating chamber, and controlling the operation of the high-frequency generator by comparing the detection result of this gas sensor with a set value. a first control means; a weight sensor for detecting the weight of the object to be heated in the heating chamber; A cooking appliance characterized by comprising a second control means for correcting so as to eliminate the problem.