JPS5934806Y2 - High frequency heating device - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a high frequency heating device with an electric oven function.

[Technical background of the invention and its problems] In general, high-frequency heating devices equipped with an electric oven function and capable of cooking food in an oven do not allow waste to be removed from the food when the electric oven function is used. etc., adhered to the walls of the heating chamber, causing serious staining.

The dirt on the walls of the heating chamber is caused by moisture, hydrocarbons, fat, salt, etc. contained in the scraps from the food being cooked, which adhere to the walls, and then only the moisture evaporates and the remaining hydrocarbons, fats, etc. turn into polymers. The main reason is that it becomes varnish-like.

In response to this problem, this varnished wall stain can be decomposed into carbon dioxide and water if it is baked at a high temperature, e.g., 700°C or higher, with sufficient oxygen, but it cannot be decomposed in a general electric oven at a high temperature. If the temperature is too high, it will oxidize other parts and significantly shorten the life of the appliance.

For this reason, as shown in FIGS. 1 and 2, a structure has been adopted in which a self-cleaning enamel 1 is applied to the inner wall of a ceiling plate 3 of a heating chamber 2 in close proximity to and facing a heater 4.

When this is done, the surface of the self-cleaning enamel reaches a temperature of 500°C or higher, at which the catalytic action is sufficiently effective, as will be described later, and the varnish-like dirt is decomposed and oxidized, releasing water and carbon dioxide. Dirt on the inner wall surface of the ceiling board 3 can be removed.

However, with the above structure, the following new problem arises.

That is, in order to raise the self-cleaning hollow surface to a high temperature of, for example, 500°C to 560°C, at which the catalytic action is sufficiently effective, it is necessary to install the heater 4 quite close to the ceiling plate 3, and this ceiling plate 3 is normally formed. When the stainless steel plate is heated by the heater 4, it undergoes a thermal change and generates a rattling sound.

To prevent this thermal deformation, a reinforcing plate 5 having a hollow cross section is provided on the outer wall of the ceiling plate 3 to increase the strength of the ceiling plate 3 and to prevent thermal deformation. The cost increases due to the addition of

Furthermore, the heated office plate 3 leaks heat to the outside, lowering the temperature inside the heating chamber 2 and lowering efficiency.

[Purpose of invention]

The present invention has been made in view of the above points, and an object thereof is to provide a high-frequency heating device that prevents deformation of the heating chamber wall surface and does not reduce efficiency.

[Summary of the idea]

In order to achieve the above object, the present invention provides a heater that is closely opposed to the wall surface of the heating chamber having the first microwave excitation port of the waveguide, and provides a self-cleaning hollow between the heater and the inner wall surface. An intermediate plate is provided with a surface facing the heater, and a second microwave excitation port is provided in a portion of the intermediate plate that faces the first microwave excitation port.

[Embodiment of the invention] The structure of an embodiment of the invention will be described below with reference to FIGS. 3 to 5.

Figures 3 and 4 show partially cutaway vertical cross-sectional views of the heating chamber with the intermediate plate attached, and 10 and 11 are the ceiling plate and side plate, respectively, which are joined by spot welding and form the heating chamber 12. Form.

A waveguide 14 with a rectangular cross section and a magnetron 13 attached to one end is fixed to the ceiling plate 10 along its outer wall.
Microwaves generated by the magnetron 13 are sent into the heating chamber 12 through a first microwave excitation port 15 formed on the lower surface of the waveguide 14 at approximately the center of the ceiling plate 10.

Now, on the inner wall surface 10a of this ceiling board 10, there is a heater 16 provided close to and opposite to this, and this heater 16 and the ceiling board 1.
Four intermediate plate mounting plates 18 and two heater support plates 19 supporting an intermediate plate 17 provided close to and facing the inner wall surface 10a between the inner wall surface 10a of the inner wall surface 10a and the inner wall surface 10a of There is.

That is, the heater 16 is formed in a rectangular shape, and the heater 16 is formed in a rectangular shape, and
Connect the power supply terminal 16a from the center of the upper part of 1a to the heating chamber 1.
2 and its both sides 16b are supported by the bottom 19a of the heater support plate 19, so that the heater support plate 10 is mounted close to and facing the inner wall surface 10aK of the ceiling plate 10.

Next, the structure of the intermediate plate 1T will be further explained using FIG. 5.

20 is a rising portion provided along the outer periphery of the intermediate plate 1γ.

Reference numeral 18 denotes intermediate plate mounting plates, which are provided by spot welding, one at each corner of the inner surface of the intermediate plate 17, which is formed into a substantially rectangular shape. Since the distance from 10a is short, the intermediate plate 11 is supported between the heater 16 and the ceiling plate 100.

Reference numeral 21 denotes a heater support plate through hole through which the heater support plate 19 passes; the heater support plate 19, which is fixed to the inner wall surface 10a of the ceiling plate 10 with screws or the like, protrudes to the outside of the intermediate plate 17 through the heater support plate through hole 21, and the heater I support 16.

Further, 22 is a second plate provided approximately in the center of this intermediate plate 11.
This prevents the intermediate plate 1T from blocking the microwaves introduced into the heating chamber 12 through the inside of the waveguide 14 at the microwave excitation port.

Furthermore, a self-cleaning hollow is applied over the entire surface of the intermediate plate 1γ, which is provided close to and facing the heater 16, to form a self-cleaning hollow surface 23.

In other words, the temperature of the self-cleaning hollow surface 23 is 500°C.
At the above temperature, a catalyst layer containing a decomposition catalyst and an oxidation catalyst for effectively decomposing and oxidizing the face-shaped polymer attached to the enamel surface 23 is formed on the surface of the intermediate plate 110 made of mild steel, aluminum, etc. It was formed.

The operation of the five configurations described above will be explained next.

In the case of open cooking, after first placing the food to be cooked in the heating chamber 12, when power is supplied to the heater 16 from a power supply section (not shown) connected to the power supply terminal 16a, the heater 16 begins to generate heat. The radiant heat starts cooking.

Next, when the food to be cooked starts to be heated, oil, dregs, etc. that come out of the food fly and adhere to the inner wall surface of the heating chamber 12 and the self-cleaning hollow surface 23 of the intermediate plate IT.

However, since the self-cleaning hollow surface 23 is provided close to and facing the heater 16, the catalyst starts to work, for example, when it is heated to 500° C. or higher, the catalyst may cause oil or debris to adhere to the self-cleaning hollow surface 23. decomposes and oxidizes the macromolecules, ultimately releasing water and carbon dioxide.

That is, for example, aluminum chloride (Atct) contained as a decomposition catalyst in the self-cleaning hollow surface 23
3) Decomposes macromolecules such as hydrocarbons contained in the scraps etc. generated from the food to be cooked into low molecules so that they can be easily oxidized. For example, vanadium pentoxide (V
2O3) decomposes the lower molecular weight hydrocarbons into water and carbon dioxide.

Furthermore, the radiant heat from the heater 16 is blocked by the intermediate plate 11 and does not reach the ceiling plate 10 directly.
The temperature of the intermediate plate 17 is as high as that of the intermediate plate 17.

That is, this intermediate plate 1T serves as a thermal buffer plate and absorbs and reflects radiant heat from the heater 16, so that even if the intermediate plate 11 reaches a temperature high enough to activate the catalyst, the ceiling plate 10
temperature does not rise that much.

Furthermore, when cooking with microwaves, as shown in FIG. The waves are radiated into the heating chamber 12 through the wave excitation port t5.22, and the food to be cooked is heated.

As described above, according to this embodiment, the inner wall surface 10 of the ceiling board 10
The ceiling plate 10 is provided with an intermediate plate 17 between the heater 16 and the heater 16 provided so that the self-cleaning hollow surface 23 approaches and opposes the heater 16.
Since the temperature of the ceiling plate 10 does not reach as high as that of the intermediate plate IT, the temperature of the ceiling plate 10 acts as a thermal shock absorbing plate for the intermediate plate IT, so there is no need to worry about thermal deformation, and the heat leakage from the ceiling plate 10 can be suppressed. This has the effect of reducing efficiency.

Further, by providing the microwave excitation port 22 in the intermediate plate IT, microwaves can be efficiently supplied into the heating chamber.

In addition, according to the embodiment shown in FIG. 3, the heater support plate 19 was conventionally made of porcelain or china, but since it is made of metal, even if the microwave oven is accidentally operated in a no-load state, As shown in FIG. 2, the microwave electric field is concentrated on the heater support plate 19, so that there is no risk of the heater support plate 19 becoming red hot and being damaged.

[Effect of idea]

As explained above, according to the present invention, a heater is provided close to and opposite to the wall surface of the heating chamber having the first microwave excitation port of the waveguide, and a self-cleaning hollow is provided between the heater and the inner wall surface. An intermediate plate is provided, the surface of which has been subjected to heating facing the heater, and a second microwave excitation port is provided on the intermediate plate in a portion opposite to the first microwave excitation port, thereby making it possible to electrically open. It can be used for a wide range of cooking tasks, including efficient cooking using microwaves.

In addition, since the intermediate plate is heated to a high temperature when using the heater, the catalytic action of the self-cleaning enamel applied to this intermediate plate can decompose and remove dirt that adheres to the intermediate plate during cooking, making cleaning easier. No longer needed.

Moreover, this intermediate plate serves as a thermal buffer plate, and the inner wall surface of the intermediate plate does not change to high temperature, so it is possible to suppress thermal deformation of the heating chamber wall surface and suppress heat radiation from the wall surface. , without reducing thermal efficiency.

Further, since the temperature of the inner wall surface can be suppressed, the thermal influence of the remagnetron, which has little heat conduction to the waveguide, is almost eliminated, and reliability can be improved.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway longitudinal sectional view of a high-frequency heating device showing a conventional embodiment, Fig. 2 is a longitudinal sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is an embodiment of the present invention. FIG. 4 is a longitudinal sectional view taken along line IV--IV in FIG. 3, and FIG. 5 is a perspective view of an intermediate plate. In the figure, 10a is an inner wall surface, 12 is a heating chamber, 16 is a heater,
11 is an intermediate plate, and 23 is a self-cleaning hollow surface.

Claims (1)

[Scope of utility model registration request] In a high-frequency heating device in which microwaves are supplied to a heating chamber through a waveguide, an inner wall surface of the heating chamber having a first microwave excitation port of the waveguide, and an inner wall surface close to and opposite to this inner wall surface are provided. a heater provided therein; an intermediate plate disposed between the heater and the inner wall surface such that a surface provided with a self-cleaning enamel faces the heater; A high-frequency heating device comprising a second microwave excitation port provided in a portion facing the excitation port.