JPS583174B2 - 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 wave energy in the microwave band is used for specific heating purposes.The configuration commonly used in such high frequency heating devices is to directly or It has a structure in which it is supplied through a waveguide to the inside of a cavity called an oven in which the object to be heated is housed.

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 heated object, that is, the difference in dielectric loss coefficient, weight, and initial temperature, that is, the temperature of the heated object before heating.

If the time adjustment is inappropriate, the object to be heated may be undercooked or overcooked.

Conventionally, as a solution to this problem, a temperature sensing element is inserted into the object to be heated, the mixture 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. This method has been 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, or initial mixing of the object, and which does not cause the object to lose its shape.

More specifically, it is intended to detect physical changes in the air flow passing through the cavity, and use the signals to control the radio wave generation source to control the heating of the object to be heated, and to reliably configure such 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.

As shown in FIG. 2, the main body 1 has a cavity 3, 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 1 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 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 surface transfer tray drive motor 11 is used as the drive source,
The coupling piece 12 connects the rotary saucer drive motor 11
The driving force of
′ is the center of rotation.

14 is an intake duct, and 15 is an intake section 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 a metal pipe 21 communicates with the exhaust opening 16 to prevent radio waves from being emitted.

17 is an exhaust duct.

The wind exiting the cavity 3 passes through the exhaust opening 16 and the baffle plate 22 and is exhausted through the exhaust duct 117.

By the way, the air baffle plate 22 is a punching plate having a group of edges provided at a portion intersecting the flow of air in the exhaust duct 17, and the airflow passing through the exhaust duct 17 is communicated through the groups of edges.

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 that detects physical changes in wind, that is, airflow, and in this embodiment, an element such as a thermistor that is sensitive to changes in the mixture of airflow is used.

The detection element 18 is provided in the path of the airflow that has passed through the air baffle plate 22.

19 is an amplification means for amplifying the signal of the detection element 18;
20 is operated by the output generated from the thousand stages of amplification 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
The radiant heat radiated from increases.

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

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 amplifying means 19 and transmitted to the control stage 20.

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

As described above, the present embodiment operates.

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, or initial mixing of the object 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.

As shown in the embodiment, a baffle plate 22 having an opening, that is, a group of small openings, is provided at a portion intersecting the flow of airflow in the exhaust duct 17, and a detection element 18 is disposed in the path of the airflow that has passed through the buffet plate 22. That is what we are doing.

The effect of this configuration is that the detection element 18 can accurately detect the progress of heating the object to be heated, and reliable heating control can be performed.

The signals transmitted from the object to be heated to the airflow are not always stable, but are often sudden or oscillating.

In particular, when an object to be heated approaches its boiling point, it suddenly releases water vapor along with bubbles (this is generally called bumping).

), or the phenomenon in which water vapor is dissipated in a wavering manner (generally referred to as fluctuation).

) occurs.

For such sudden or oscillating signal changes,
The air conditioning plate 22 has a braking function, and has openings formed by a group of edges, and the groups of edges perform a smoothing effect on the disturbance of the signal.

Therefore, the detection element 18 can accurately detect the heating progress of the object to be heated without being affected by signal disturbances, eliminate malfunctions and abnormal operations of the control stage 20, and ensure reliable heating control. become.

By the way, in the embodiment, a punching plate having a group of edges is used as the wind regulating plate 22, but the same effect can be obtained by using other means such as a net-like body having openings.

As described above, according to the present invention, the heating of the object to be heated can be controlled without deforming the object, regardless of the type, weight, or initial mixing of the object, and the means for doing so can be reliably configured. It is possible to provide a high-frequency heating device that can.

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 the drawing]

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, 1
6... 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 airflow passes, and an exhaust duct 17 communicates with the exit side of the airflow of the opening. A baffle plate 22 having an opening is provided at a portion intersecting the air flow of the exhaust duct 17.
A high-frequency heating device comprising: a detection element 18 for detecting a physical change in the airflow in the path of the airflow that has passed through the air conditioning plate 22. (2) A high-frequency heating device according to item 1 of the scope of the patent, characterized in that the air conditioning plate 22 is a punching plate having a group of edges. 3. The high-frequency heating device according to claim 1, wherein the air conditioning plate 22 is a net-like body having openings.