JPS5828500B2 - High frequency heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency heating device for heating an object using radio wave energy, and more particularly to a means for controlling the heating of an object to be heated by the device.

It is well known that radio energy in the microwave band is used to heat objects.

A common configuration of such high-frequency heating devices is to supply radio waves emitted from a radio wave generation source such as a magnetron directly or through a waveguide to the inside of a cavity called an oven in which the object to be heated is housed. It is of composition.

In the apparatus having such a configuration, the heating time of the heated object is usually controlled by timer means or the like.

In this case, it is necessary to adjust the heating time appropriately depending on the type of the object to be heated, that is, the difference in dielectric loss coefficient, the weight, and the rice grain temperature, that is, the temperature of the object to be heated before heating.

If the time adjustment is inappropriate, the result will be that the object to be heated is under-heated or over-heated.

Conventionally, as a solution to this problem, a temperature sensing element is inserted into the object to be heated, the temperature of the object to be heated is directly detected, and the oscillation of the magnetron is controlled to control the heating of the object to be heated. methods are being used.

In the device having such a means, the object to be heated loses its shape,
This may cause damage by interfering with cooking.

SUMMARY OF THE INVENTION Therefore, the present invention aims to provide a means for controlling the heating of an object to be heated, regardless of the type, weight, and temperature of the heated object, and which does not cause deformation of the object.

More specifically, it is desired to detect a physical change in the air flow passing through the cavity and control a radio wave generation source using the signal to control the heating of the object to be heated, and to reliably configure such a means. There is an aim of the present invention.

Examples will now be described with reference to the accompanying drawings.

In FIG. 1, 1 is the main body of the device, and 2 is a door attached to the main body 1 so as to be openable and closable.

The main body 1 has a cavity 3 as shown in FIG. 2, and a door 2 is disposed to close an entrance/exit (not shown) of the cavity 3 for the object to be heated.

In FIGS. 2 and 3, 4 is a magnetron that is a radio wave generation source.

Reference numeral 5 denotes a blower for cooling the magnetron 4. The blower 5 is surrounded by an air guide 7, and the air guide 7 is provided with a blower intake port 6.

8 is an exhaust air guide for the wind that cools the magnetron 4, and 9 is an antenna cover that surrounds the antenna section of the magnetron 4.

The antenna cover 9 is made of a dielectric material with low loss at high frequencies.

Reference numeral 10 denotes a rotating saucer, on which the object to be heated 13 is placed, the rotating saucer drive motor 11 is the driving source, and the driving force of the rotating saucer drive motor 11 is transmitted through the coupling piece 120. The rotation receiving tray 10 is rotated around the rotation axis o.
-o' is the center of rotation.

14 is an intake duct, and 15 is an intake opening formed in the cavity 3.

The wind entering the cavity 3 passes through the intake duct 14 to the intake opening 1
5 into the cavity 3.

Reference numeral 16 denotes an exhaust opening formed in the cavity 3, and the exhaust opening is made of a metal pipe to prevent radio waves from being emitted.

17 is an exhaust duct.

The air leaving the cavity 3 is exhausted through the exhaust opening 16 and through the exhaust duct 17 .

One end of the exhaust duct 17 is disposed near the blower intake port 6 so that the intake force of the blower 5 acts on the exhaust duct 17.

Reference numeral 18 denotes a detection element for detecting physical changes in the wind, that is, airflow, and in this embodiment, an element such as a thermistor that is sensitive to temperature changes in the airflow is used.

19 is an amplification means for amplifying the signal of the detection element 18;
20 is operated by the output generated from the amplification means 19;
This is a control means for controlling the oscillation of the magnetron 4.

Reference numeral 22 denotes a control valve that is a means for adjusting the flow rate of the airflow passing through the sensing element 18. The control valve 22 is operated by the valve 1 driving section 23, and adjusts the flow rate of the airflow according to the setting conditions of the operation section 24.

Reference numeral 25 denotes an output variable means of the magnetron, which is a radio wave generation source, and changes the output of the magnetron according to the setting conditions of the operating section 24.

At this time, a means for adjusting the flow rate of the airflow is activated in response to the output variable means, so that an appropriate flow rate of the airflow passes through the detection element 18.

Next, the operation of the above embodiment and the effects of each part will be explained.

Radio waves generated by the magnetron 4 are radiated into the cavity 3 and heat the object 13 to be heated.

The object to be heated 13 rotates together with the rotating tray 10 and is uniformly heated.

As the heating of the heated object 13 progresses, the heated object 1
Radiant heat radiated from 3 increases.

This heat is transferred to the sensing element 18 by the wind passing through the cavity 3.

The detection element 18 generates a signal in response to a change in the radiant heat of the object 13 to be heated.

The signal generated from the sensing element 18 is amplified by the amplification means 19 and transmitted to the control means 20.

Therefore, when the object to be heated reaches a desired temperature, the control means 20 is activated, the oscillation of the magnetron 4 is controlled, and Kerr control of the object to be heated is performed.

The present embodiment operates as described above.

Incidentally, the first feature of this embodiment is that the heating of the object to be heated is not controlled by a timer.

Therefore, since it is not necessary to adjust the heating time, it becomes possible to control the heating of the object to be heated to a desired temperature regardless of the type, weight, and temperature of the rice to be heated.

The second feature is that the detection element 18 is not directly inserted into the heated object to detect the temperature change of the heated object, which is a so-called indirect detection method, so the heated object does not lose its shape. .

The third characteristic is the uniqueness of the wind path.

That is, as described above, the means for adjusting the flow rate of the airflow passing through the detection element 18 and the means for varying the output of the radio wave generation source are made to respond in response.

The effect of this is that the relationship between the heating progress of the heated object and the detection element 18 can be maintained stably even if the output changes.

This is because, for example, when the radio wave generation source has a weak output, if the flow rate of airflow passing through the sensing element 18 is large, the amount of heat generated per unit time of the heated object is small, so the sensing element 18 detects the heated object. This means ensuring that there is no possibility that a signal sufficient for control cannot be obtained.

In addition, in the case of strong output, if the flow rate is small, it becomes sensitive to disturbances, which means that it is necessary to prevent premature or malfunctioning.

'As described above, according to the present invention, the type, weight,
It is possible to provide a high-frequency heating device that can control the heating of an object to be heated without causing the object to be heated to lose its shape regardless of the rice grain temperature, and that can reliably configure the means therefor.

In addition, in the embodiment, a configuration was presented in which the oscillation of the magnetron is controlled by capturing the temperature change of the airflow passing through the cavity, but the configuration is not necessarily limited to such a configuration.
For example, the idea of the present invention can also be applied to a structure in which the heating of the object to be heated is controlled by controlling the oscillation of a magnetron using other physical changes such as changes in the humidity of airflow due to water vapor generated from the object to be heated. Needless to say, it can be done.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a high-frequency heating device according to the present invention,
FIG. 2 is a schematic vertical cross-sectional view of the main part, and FIG. 3 is a schematic cross-sectional view of the main part. 3...Cavity, 4...Magnetron, 5
...Blower, 18...Detection element.

Claims (1)

[Claims] 1 It has a cavity 3 for storing the object to be heated, the cavity 3 has an opening through which the airflow passes, and a detection element 1B that detects a physical change in the airflow is located near the exit side of the airflow of the opening. 1. A high-frequency heating device characterized in that the high-frequency heating device is equipped with a means for controlling the flow rate of airflow passing through the detection element 18, and the means is responsive to an output variable means of a radio wave generating source.