JPS5821181B2 - 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 rice 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 heating control means for a heated object that does not depend on the type, weight, or rice temperature of the heated object and does not cause deformation of the heated object.

More specifically, it detects physical changes in the airflow passing through the cavity, controls the radio wave generation source using the signals, and heats and sterilizes the object to be heated. , is the 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 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 underside of the magnetron 4.

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

10 is a rotating saucer, and the heated object 1 is placed in the rotating saucer 10.
3 is placed, and the rotary tray 1 drive motor 11 is used as a driving source, and the driving force of the rotary tray drive motor 11 is transmitted through the coupling piece 12, and the rotary tray 10 is moved to the rotation axis 0.
It is configured to rotate with -0' as 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 is introduced into the cavity 3 via the intake duct 14 and through the intake opening 15 .

Reference numeral 16 denotes an exhaust opening formed in the cavity 3, and the exhaust opening 16 is connected to the metal pipe 2 in order to prevent harmful radio waves.
1 is connected.

17 is an exhaust duct.

The wind leaving the cavity 3 is exhausted through the exhaust opening 16 and through the exhaust duct 17 at 1.

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 barrier provided on the side of the cavity 3 when viewed from the detection element 18, facing the detection element 18, and the barrier 22 is disposed to cross the flow of the airflow.

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 object to be heated 13 progresses, the object to be heated 13
The radiant heat radiated from 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 the heating of the object to be heated 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.

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 object to be heated, but it is a so-called indirect detection method that detects the temperature change of the object to be heated, so the object to be heated does not lose its shape. be.

The third characteristic is the uniqueness of the wind path.

As shown in the embodiment, a barrier 22 that crosses the airflow is provided in correspondence with the sensing element 18.

The effects of having such a configuration include malfunction or abnormal operation of the control circuit system, such as chattering of switching elements, etc., in response to physical changes in the airflow that occur suddenly, or changes that occur while fluctuating. It is possible to prevent such problems from occurring.

An example of a sudden change is a so-called bumping phenomenon, which occurs when a heated object containing moisture reaches near the point of collision and suddenly diffuses water vapor along with bubbles.

Further, as a fluctuation phenomenon, there is a phenomenon in which the water vapor generated from the heated object becomes denser and denser in time.

However, in the present invention, as described above, the sensing element 1
8 is provided with a barrier 22 that intersects the flow of the airflow, so that the barrier 22 detects these phenomena by detecting the sensing element 18.
The above-mentioned problem can be solved because it has the effect of relieving the need for prompt communication.

Further, the peculiarity of the air path is that the sensing element 18 and the barrier 22 are arranged at separate positions.

The effect of such a configuration is that when the object to be heated is repeatedly heated, the heat capacity of the barrier 22 causes conduction and radiation of heat stored in the barrier itself, which gives an incorrect symbol to the detection element 18. It lies in being able to avoid harm.

As a development of the idea of the present invention, it is also possible to provide the sensing element 18 outside the cavity 3 as shown in FIG. It does not deviate from this.

As described above, according to the present invention, it is possible to control the heating of the object to be heated without deforming the object, regardless of the type of the object to be heated or the weight and rice temperature, and the means for doing so can be reliably configured. A high frequency heating device can be provided.

In addition, in the embodiment, a configuration is 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. FIG. 4 is a schematic cross-sectional view of main parts in another embodiment. 3... Cavity, 4... Magnetron, 5... Blower, 16... Exhaust opening, 18... Detection element, 22...
··barrier.

Claims (1)

[Claims] 1. A cavity 3 for storing an object to be heated, an opening through which air flows, and a physical change in the air flow near the outlet of the opening. A high-frequency heating device comprising a detection element 8 that detects the detection element 18, and a barrier 22 that intersects the air flow path in the air flow path leading to the detection element 18 and is provided at a position away from the detection element 18. 2. In claim 1, the barrier is the sensing element 1
A high-frequency heating device characterized in that it is disposed on the cavity 3 side with respect to 8. 3 In claim 1, the barrier is the sensing element 1
8. A high-frequency heating device characterized in that it is disposed outside the cavity 3.