JPS598723B2 - 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 the 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 a configuration in which radio waves emitted from a radio wave generation source such as a magnetron are supplied directly or through a waveguide to the inside of a cavity called an open cavity in which the object to be heated is housed. belongs to.

In the apparatus having such a configuration, the heating time of the object to be heated is usually controlled by a timer such as a timer.

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 initial temperature, that is, the temperature K of the object before heating.

If the time adjustment is inadequate, the heated object will suffer the consequences.

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, it is an object of the present invention to provide a means for controlling the heating of an object to be heated, regardless of the type, weight, or initial temperature of the object, and which does not cause the object to lose its shape.

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 be described below 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 FIG. 2, 4 is a magnetron which is a radio wave generation source.

5 is a blower for cooling the magnetron 4, and the blower 5 communicates with an air guide 6.

7 is an exhaust air guide for cooling the magnetron 4, and 8 is an antenna cover that surrounds the antenna section of the magnetron 4.

The antenna cover 8 is made of a dielectric material with low loss at high frequencies.

9 is a rotating saucer. An object to be heated 12 is placed on the rotating saucer 9, and a rotating saucer driving motor 10 is used as a driving source, and the driving force of the rotating saucer driving motor 10 is transmitted through the coupling piece 11. It is configured to perform rotational movement.

13 is a fan motor for passing airflow into the cavity 3, and 14 is an intake duct.

Reference numeral 15 denotes an intake opening formed in the cavity 3.

The wind entering the cavity 3 is introduced into the cavity 3 via the intake duct 14 and through the intake opening 15 .

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 fan motor intake port 6 and is configured to act on the intake side air duct 17 of the fan motor 13.

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.

20 is a duct for discharging the airflow passing through the cavity 3 to the outside of the main body 1.

21 is an amplification means for amplifying the signal of the detection element 18;
22 is operated by the output generated from the thousand stages of amplification 21,
This is a control means for controlling the oscillation of the magnetron 4.

23 is a means for controlling the rotation speed of the fan motor 130 that passes airflow into the cavity 3, and 24 is an operating means thereof.

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 12 to be heated.

The object to be heated 12 rotates together with the rotating tray 9 and is uniformly heated.

As the heating of the object to be heated 12 progresses, the radiant heat radiated from the object to be heated 12 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 changes in the radiant heat of the object 12 to be heated.

The signal generated from the sensing element 18 is amplified by the amplification means 21 and transmitted to the control means 22.

At this point, when the object to be heated reaches a desired temperature, the control stage 22 is activated, the oscillation of the magnetron 4 is controlled, and the object to be heated cW4 is controlled.

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.

Since the heating time does not need to be adjusted, the heating of the object can be controlled to a desired temperature regardless of the type, weight, or initial temperature of the object.

The second feature is that it is a so-called indirect detection method that detects the temperature change of the heated object without directly pushing the sensing element 18 into the heated object, 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 number of rotations of the fan motor 130 that generates the airflow passing through the detection element 18 can be controlled from the outside.

The function and utility of being able to control the fan motor 130 rotation speed is to accurately grasp the heating progress of the heated object.
It is possible to change the flow rate of airflow.

This means that when the flow rate is increased, the response tends to be delayed, and when the flow rate is decreased, the response tends to be faster.
The number of revolutions was changed to 30.

For example, if you want to heat rice in bulk, you can increase the rotation speed to delay the response of the detection element 18, and if you want to finish heating with a low degree of saturation, such as when heating a sake pot, you can lower the rotation speed. , - The flow rate of the airflow may be reduced to speed up the response of the sensing element 18 and shorten the heating time.

As described above, according to the present invention, it is possible to control the heating of an object to be heated without causing the object to be heated to deform, regardless of the type of the object to be heated, its initial weight or initial temperature, and the means for doing so can be reliably configured. Can you provide high frequency heating equipment?

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 the magnetron using other physical changes such as changes in the humidity of airflow due to water vapor generated from the object to be heated. It's not even possible to say what can be done.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a perspective view of a high-frequency heating device according to the present invention.
FIG. 2 is a schematic cross-sectional view of the main part. 3... Cavity, 4... Macnetron, 13... Fan motor, 18... Detection element, 23... Rotation speed control means, 24... Operating means.

Claims (1)

[Claims] 1 has a cavity 3 for storing an object to be heated, has an opening through which the airflow passes, and has a detection element 18 near the outlet side of the airflow that detects a physical change in the airflow. A high-frequency heating device characterized by comprising: means for controlling the number of rotations of a fan motor 13 that generates an airflow passing through the detection element 18; and an operating means for operating the fan motor 13.