JPS5821182B2 - 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 oven 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 inadequate, the result will always be that the object to be heated is undercooked or overcooked.

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. Many methods have been developed.

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 means for heating an object to be heated, regardless of the type, weight, or rice temperature of the object to be heated, 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 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 cooling the magnetron 4, and 9 is an antenna cover that surrounds the antenna section of the magnetron 4.

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

Reference numeral 10 designates a rotating saucer. A heated object 13 is placed on the rotating saucer 111110. The rotating saucer driving motor 11 is used as a driving source, and a coupling piece 12 connects the rotating saucer to the driving force of the drive motor 11. As a result of the transmission, the rotating tray 10 is configured to rotate around the rotating shaft 0-07 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 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 1γ.

18 is a detection element that detects physical changes in wind, that is, airflow.

In this embodiment, an element such as a thermistor that is sensitive to temperature changes in the airflow is used.

The detection element 18 is arranged in the airflow path of the exhaust duct 17.

Its position is the air baffle plate 22 provided inside the exhaust duct 17.
This is the position where the density of the airflow formed by is dense.

The air baffle plate 22 is provided at a portion of the exhaust duct 17 where the path of the airflow is bent by the exhaust duct 1T, and has one wall that is smoothly bent or inclined to guide the airflow smoothly.

The sensing element 18 is mounted on an extension of the path of the airflow flowing along the curved or inclined wall surface.

The arrows in the diagram of FIG. 2 indicate the flow of airflow.

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.

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
Increases heat dissipation from

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 heat radiation of the object to be heated 13 .

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 to control the oscillation of the magnetron 4, thereby controlling the heating of the object to be heated.

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 it is a so-called indirect detection method that detects temperature changes of the heated object without directly inserting 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 shown in the embodiment, the airflow is guided along the air baffle plate 22 provided in the exhaust duct 17, and the detection element 18 detects the air flow along the wall surface of the air baffle plate 22. The detection element 18 is arranged at a position apart from the air regulating plate 22.

The effect of this configuration is that the detection element 18 can accurately detect physical changes in the airflow that change as the heating progresses on the object to be heated, and the heat capacity of the air conditioning plate 22 allows it to detect the heat stored in the air conditioning plate itself. It is possible to avoid the damage of giving a false signal to the detection element when the object to be heated is repeatedly heated by conduction or radiation.

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. 3... Cavity, 4... Magnetron, 5... Blower, 15... Intake opening, 16... Exhaust opening, 17
... Exhaust duct, 18... Detection element, 22... Air conditioning plate.

Claims (1)

[Claims] 1 It has a cavity 3 for storing the object to be heated, and the cavity 3 has an opening through which the airflow flows, and an exhaust duct 17 is connected to the outlet side of the airflow of the opening, and the exhaust duct An air baffle plate 22 is interposed between the air current baffle plate 22 and the sensing element 18 at a location away from the sensing element 18, and the airflow is guided to the sensing element portion through the airflow along the air baffle plate 22, and radio waves are generated by capturing physical changes in the air flow. A high-frequency heating device characterized by being configured to control a generation source.