JPH0620004Y2 - microwave - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a microwave oven having a function of detecting a finished condition of an object to be heated by a sensor provided in a heating chamber.

<Prior art> When reheating a drink, milk, coffee, etc. (hereinafter,
In the case of milk, etc., the finishing temperature is 80 ° C or higher, but in the case of drinking sake, the finishing temperature is about 55 ° C. Therefore, in the conventional microwave oven, various sensors are provided in the heating chamber, the type is discriminated from the characteristics of the object to be heated, and the optimum finishing temperature is automatically controlled.

That is, in the case of sake liquor, as shown in FIG. 6, after the start of heating, the first set time T1 has elapsed and the finishing temperature (about 55 ° C.)
When it comes close, the detection result of the gas sensor rapidly rises, but the detection result of the humidity sensor has a characteristic that it hardly rises. On the other hand, in the case of milk or the like, as shown in FIG. 7, the detection result of the gas sensor hardly increases and the detection result of the humidity sensor 5b also almost increases even after the same first set time T1 as in the case of drinking sake. There is a characteristic that does not.

Therefore, the control circuit uses the difference between the detection results of the gas sensor, and if the detection result of the gas sensor after the first set time T1 has elapsed after the start of heating is a constant value G1 or more, the object to be heated is liquor. Judge and finish heating. If the detection result of the gas sensor is less than the constant value G1, it is determined that the object to be heated is milk or the like, and heating is continued until the detection result of the humidity sensor sharply rises (about 80 ° C. or higher).

<Problems to be Solved by the Invention> In the above-mentioned conventional technique, when sake is sake with a narrow mouth, after the start of heating, the first set time T1 elapses and the finish temperature (about 55 ° C) is reached. However, as shown in FIG. 9, there is a problem that the detection result of the gas sensor does not sufficiently rise, the object to be heated is discriminated as milk or the like, and the object is overheated.

Therefore, the present invention provides a microwave oven that can surely determine the type of object to be heated even if heating is performed in a state where it is difficult to determine the type of object to be heated, such as drinking sake with a narrow mouth. With the goal.

<Means for Solving Problems> The means for solving problems according to the present invention is, as shown in FIGS. 1 to 5, a fan 4 for blowing air into the magnetron 2 and the heating chamber 3 when the object 1 to be heated is heated. And the exhaust port 16 of the heating chamber 3
A plurality of types of sensors 5 for detecting the environment inside the heating chamber 3 and a control circuit 6 for controlling the magnetron 2 and the blower fan 4 are provided. The heating means 6a for driving the magnetron 2 and the blower fan 4 for a time T1, and the driving of the blower fan 4 for a second set time T2 after the first set time T1 has elapsed, and the second set time T2 has elapsed. After that, the blower means 6b for re-driving the blower fan 4 for the third set time T3.
After the first set time T1, the magnetron stop means 6c for stopping the driving of the magnetron 2 for the second set time T2 and the third set time T3, and the third set time T3 from the re-driving of the blower fan 4. After the elapse, the type of the article to be heated 1 is discriminated based on the detection result of the sensor 5 and the discrimination means 6d for controlling the blower fan 4 and the magnetron 2 based on the discrimination result.

<Operation> In the above problem solving means, when the first set time T1 elapses after the start of heating, the heating means 6a of the control circuit 6 stops the magnetron 2 and the blower fan 4. Then, the heating chamber 3 is filled with gas or the like generated from the object to be heated 1,
The gas concentration in the heating chamber 3 increases.

And after stopping the magnetron 2 and the blower fan 4,
When the second set time T2 has elapsed by the blower 6b, the blower fan 4 is driven. Then, the gas filled in the heating chamber 3 is discharged from the exhaust port 16, contacts the sensor 5, and the detection result thereof rises. When the third set time T3 elapses after the blowing fan 4 is re-driven, the discriminating means 6d discriminates the type of the article to be heated 1 by examining the detection result of the sensor 5. During this time, the magnetron 2 remains stopped.

That is, since the air blower fan 4 is once stopped and the heating chamber 3 is sufficiently filled with gas, air is blown again to detect the gas concentration, so that the type of the article to be heated 1 can be reliably determined.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 1 is a functional block diagram showing the microwave oven of the present invention, FIG. 2 is the same flow chart, FIG. 3 is the same electric circuit diagram, FIG. 4 is the same vertical side view of the heating chamber, and FIG. 5 is the same magnetron and It is a diagram which shows the drive state of a ventilation fan, and the detection result of a sensor.

Then, as shown in the drawing, the microwave oven of the present invention includes the object 1 to be heated.
When heated, the magnetron 2, a fan 4 for blowing air into the heating chamber 3, a plurality of types of sensors 5 arranged at the exhaust port 16 of the heating chamber 3 for detecting the environment inside the heating chamber 3, the magnetron 2 and A control circuit 6 for controlling the blower fan 4 is provided, and the control circuit 6 controls the magnetron 2 and the blower fan 4 for a first set time T1 from the start of heating.
The heating means 6a for driving the air blower 4 and the driving of the blower fan 4 are stopped for a second set time T2 after the first set time T1 has passed, and the blower for the third set time T3 after the second set time T2 has passed. The blower means 6b for re-driving the fan 4 and the second set time T2 and the third set time T after the first set time T1 has elapsed.
The magnetron stopping means 6c for stopping the driving of the magnetron 2 during 3 and the type of the heated object 1 is discriminated based on the detection result of the sensor 5 after the elapse of the third set time T3 from the re-driving of the blower fan 4. It has a discrimination means 6d for controlling the blower fan 4 and the magnetron 2 based on the discrimination result.

The magnetron 2 is of a general type used in a microwave oven, and is driven by a high voltage transformer 8 connected to a commercial AC current 7 as shown in FIG. And the third
As shown in the drawing, the first relay 10 connected to the first output terminal 9 of the control circuit 6 is operated or stopped when the first relay 10 is opened or closed. 1
Reference numeral 1 is a driving transistor of the first relay 10.

As shown in FIG. 4, the blower fan 4 is arranged outside the ventilation port 12 provided on the side surface of the heating chamber 3 and is connected to the second output terminal 13 of the control circuit 6 as shown in FIG. (2) The relay 14 is operated or stopped when the relay 14 is opened or closed. Reference numeral 15 is a driving transistor for the second relay 14.

As shown in FIG. 4, the sensor 5 has an exhaust port 16 of the heating chamber 3.
Are a gas sensor 5a and a humidity sensor 5b arranged outside the room. The gas sensor 5a is a gas (alcohol, etc.) in the heating chamber 3.
The humidity sensor 5b detects the humidity inside the heating chamber 3.

The control circuit 6 is a general one-chip type microcomputer, and has a central processing unit (CPU) 17,
It has a read-only storage device (ROM) 18, a readable / writable storage device (RAM) 19, an input / output device (I / O) 20, and the like. Then, the output terminals 9 and 13 of the I / O 20
The first relay 10 and the second relay 14 are connected to the through relays 11 and 15 for driving. Further, the gas sensor 5a and the humidity sensor 5b are connected to an input terminal of the I / O 20 by an analog / digital converter (A / D).
In addition to being connected via the converters 21 and 22, an operation unit 23 for operating various functions of the microwave oven is connected.

The heating means 6a, the blowing means 6b, the magnetron stopping means 6c and the discriminating means 6d are composed of a micro computer.

In FIG. 3, 24 is a high-voltage capacitor, 25 is a high-voltage diode, and 26 is a turntable on which the object to be heated 1 is placed.

A case where the "drinks" key 23a of the operation unit 23 is pressed and automatic heating of the drinks is selected in the above configuration will be described with reference to FIGS. 2 and 5.

When the first set time T1 elapses after the start of heating, the control circuit 6 turns off the first relay 10 and the second relay 14, and stops the magnetron 2 and the blower fan 4.
Then, the heating chamber 3 is filled with gas or the like generated from the object to be heated 1, and the gas concentration in the heating chamber 3 increases. But,
Since the blower fan 4 is stopped, the air in the heating chamber 3 is not sent to the vicinity of the gas sensor 5a, and the detection result of the gas sensor 5a slightly decreases as shown in FIG.

And after stopping the magnetron 2 and the blower fan 4,
When the second set time T2 has elapsed, the control circuit 6 drives only the blower fan 4 while keeping the magnetron 2 stopped. Then, the gas filled in the heating chamber 3 is discharged from the exhaust port 16, and the detection result of the gas sensor 5a rises.

At this time, the detection result of the humidity sensor 5b hardly increases. This is because the first set time T1 is a heating time suitable for sake liquor, and in order to bring the object 1 to be heated to a temperature suitable for sake liquor (about 55 ° C.), steam is still sufficient from the object 1 to be heated. This is because it does not occur.

Then, the control circuit 6 checks the detection result of the gas sensor 5a at the time when the third set time T3 elapses after the blowing fan 4 is re-driven, and if the detection result is a predetermined value G1 or more, the object to be heated 1
Determines that it is sake and ends heating. If the detection result is less than the constant value G1, it is determined that the object to be heated 1 is milk or the like, the magnetron 2 is driven again, and the humidity sensor 5b
The object to be heated 1 is heated until the detection result of 1 rises.

That is, since the blower fan 4 is once stopped and the gas concentration is detected after the heating chamber 3 is sufficiently filled with gas, the heated object 1 is surely heated even when drinking sake with a sake bottle with a narrow mouth.
The type of can be determined.

It should be noted that the present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes are made to the above embodiment within the scope of the present invention.

For example, the sensor is not limited to the gas sensor and the humidity sensor as in the above embodiment, but other environment detection sensors (for example, temperature sensors) may be used according to the characteristics of the object to be heated.

<Effect of Device> As is clear from the above description, according to the present invention, the environment inside the heating chamber is kept in a steady state by heating for the first set time and stopping the magnetron and the fan for the second set time. Since the sensor detects this state by driving the blower fan during the third set time thereafter, the environment inside the heating chamber can be accurately known.

Therefore, even if heating is performed in a state where it is difficult to determine the type of object to be heated, such as sake drinking with a narrow mouth,
If the type of object to be heated can be surely discriminated, an excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the microwave oven of the present invention, and FIG.
The figure is also a flow chart, FIG. 3 is also an electric circuit diagram, FIG. 4 is also a vertical side view of the heating chamber, and FIG. 5 is a diagram showing the driving states of the magnetron and the blower fan and the detection results of the sensors. Fig. 6 is a diagram showing the detection results of a conventional sensor when drinking sake, Fig. 7 is a diagram showing the detection results of a sensor when heating milk or the like, and Fig. 8 is also a diagram showing detection results of a sensor when drinking milk or milk. FIG. 9 is a diagram comparing the detection results of the gas sensor at the time, and FIG. 9 is a diagram comparing the detection results of the gas sensor at the time of drinking sake at Sake sake with a narrow mouth. 1: Object to be heated, 2: Magnetron, 3: Heating chamber, 4: Fan fan, 5: Sensor, 5a: Gas sensor, 5b: Humidity sensor, 6: Control circuit, 6a: Fan driving means, 6b: Magnetron driving means, 6c: Discrimination means.

Claims (1)

[Scope of utility model registration request] 1. A magnetron for heating an object to be heated, a blowing fan for blowing air into a heating chamber, a plurality of types of sensors arranged at an exhaust port of the heating chamber for detecting an environment inside the heating chamber, the magnetron and A control circuit for controlling the blower fan is provided, and the control circuit includes heating means for driving the magnetron and the blower fan for a first set time from the start of heating, and a second set time after the first set time has elapsed. An air-blowing means for stopping the driving of the air-blowing fan for a third set time after the second set time has elapsed, and
After the first set time has elapsed, the magnetron stopping means for stopping the driving of the magnetron for the second set time and the third set time, and based on the detection result of the sensor after the third set time has elapsed from the re-driving of the blower fan. And a discrimination means for discriminating the kind of the object to be heated and controlling the blower fan and the magnetron based on the discrimination result.