JPS61292891A - High frequency heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a high-frequency heating device, and more particularly to an improvement in a high-frequency heating device in which a rotating waveguide is provided in a heating space.

[Technical background of the invention and its problems]

In a microwave oven (high-frequency heating device), a rotating waveguide is installed inside the heating chamber, and the rotating waveguide irradiates microwaves (high-frequency waves) into the heating chamber to effectively heat the food being cooked. There is something like this.

Conventionally, such microwave irradiation techniques as shown in FIGS. 6 and 7 have been used. That is, a rotating waveguide is formed into a container shape from a metal plate such as an aluminum plate, and has an excitation opening a in the bottom wall, and this is placed on the upper side of the heating Nc to generate a magnetron d (oscillation device). ), a structure is used in which the rotating waveguide is connected to a motor (drive source) e placed outside the heating 9-c, and the rotating waveguide Microwaves were irradiated into the heating chamber C from the excitation S aperture a, which rotated as the heating chamber moved. Note that f indicates a waveguide for guiding the microwave oscillated from the magnetron d to the rotating waveguide l.

However, with this technique of irradiating microwaves from the excitation opening f in the bottom wall, the irradiation direction of the microwaves is mainly downward (directly below). Stronger than the rest. For this reason, there is a problem of uneven heating.

In particular, when there is a large cooking object 0, or when the cooking object Q is in the heating chamber C.
When placed toward the inner corner, the non-uniformity of irradiation appears greatly, resulting in a problem of large uneven heating.

[Purpose of the invention]

The present invention was made in view of these problems, and its purpose is to provide a high-frequency heating device that can uniformly irradiate a heated object with high-frequency waves.

[Summary of the invention]

That is, this invention provides a second excitation opening in the peripheral wall of the rotating waveguide, separate from the excitation opening provided in the bottom wall, so that the irradiation direction can be made multidirectional, and the object to be heated can be directly irradiated with high frequency waves. At the same time, it is possible to irradiate the object with high frequency waves from all directions by using reflection (dispersion) of the heated wall surface to irradiate high frequency waves to parts of the object that are difficult to irradiate.

[Embodiments of the invention]

The present invention will be explained below based on an embodiment shown in FIGS. 1 to 3. FIG. 1 shows a high-frequency heating device, such as a microwave oven, to which the present invention is applied, and 1 is a main body, 2
3 is the heating chamber arranged in the main body 1, and 3 is the heating chamber 2.
An excitation opening 4 provided in the upper wall of the waveguide is a waveguide with a magnetron 5 connected to one end thereof. A waveguide 4 is installed on the upper wall of the heating chamber 2, and the outlet side of the waveguide 4 is connected to the opening 3 to supply microwaves (high frequency) oscillated from the magnetron 5 to the heating chamber 2. I'm trying to be able to do that.

On the other hand, 6 is a rotating waveguide. The structure of the rotating waveguide 6 is shown in FIG. Here, if the rotating waveguide 6 is explained, 7 is a waveguide main body. The waveguide body 7 is made of a conductive material such as an aluminum plate or molded with resin, and is configured in the shape of a vessel with a rectangular opening, for example.

In addition, in the case of resin molding, metal plating is applied to the surface.

A fixing hole 8 is provided on the bottom wall of the waveguide body 7 at a position eccentric from the center toward one end, and a rectangular excitation opening 9 is provided at the other end opposite to this. are provided along the width direction. Further, second excitation openings 10 each having a rectangular shape are provided in the peripheral wall portions 7a and 7b of the two walls adjacent to the excitation opening 9 of the rotating waveguide 6. These two second excitation openings 10.10 are arranged adjacent to the excitation opening 9 provided in the bottom wall, so that microwaves can be emitted from one location in three different directions. . The rotating waveguide 6 is arranged at the upper side of the heating chamber 2 so that its opening faces the opening 3, so that it can receive the microwaves emitted from the opening 3.

On the other hand, 11 is a motor installed on the outer surface of the upper wall of the waveguide 4, located directly above the opening 3. The tip of the shaft 11a of this motor 11 extends through the waveguide 4 to just below the opening 3. As shown in FIG.
2, and the rotating waveguide 6 can be eccentrically rotated using a motor as a driving source.

Of course, the opening of the rotating waveguide 6 is large enough to accommodate the entire opening 3, as well as the second excitation opening 10.
10 is determined to be a size that allows microwaves to be easily emitted.

In FIG. 1, reference numeral 13 is made of a material having excellent radio wave transparency, such as heat-resistant plastic, heat-resistant resin, etc., which is provided to cover the rotating waveguide 6 and protect the rotating waveguide 6. This is a structured partition plate.

Next, the operation of the microwave oven configured as described above will be explained. Now, there are 14 things to be cooked (things to be heated) in the heating chamber 2.
and operates the operating section of the microwave oven (not shown).

This causes the magnetron 5 and motor 11 to operate. Then, microwaves are oscillated from the magnetron 5, guided through the waveguide 4° opening 3 to the rotating rotating waveguide 6, and irradiated into the heating chamber 2.

Here, it has been pointed out that conventionally, heating unevenness occurs because microwaves are not uniformly irradiated onto the food 14 to be cooked, but according to the present invention, heating unevenness can be eliminated.

That is, according to the invention, in addition to the excitation opening 9 in the bottom wall, a second excitation opening 10.10 is provided in the peripheral wall of the rotating waveguide 6. This means that the microwave guided into the rotating waveguide 6 is divided into the excitation aperture 9 and the second excitation aperture 10.10. The microwaves that reach the excitation opening 9 on the bottom wall side are emitted downward (directly below) as shown by A in FIGS. irradiated. On the other hand, the microwaves reaching the second excitation opening 10.10 are emitted to the peripheral side wall of the heating chamber 2, as shown by 8 in FIGS. 1 and 2, and are also reflected by the peripheral side wall (
Dispersed) and difficult to irradiate with direct irradiation14
The area around the body is irradiated. However, cooking item 1
Microwaves are uniformly irradiated to both the upper and the surrounding areas of 4.

Moreover, since the reflected (dispersed) microwaves are irradiated from random directions around the heating chamber 2,
4, even when the food 14 is placed toward the corner of the heating chamber 2, the entire area will be uniformly irradiated. This shows that all parts of the food 14 are uniformly irradiated with microwaves. Therefore, heating can be performed without uneven heating. Moreover, by adopting the second excitation aperture 10.10, the area from which the microwaves are emitted is larger than that of the conventional one, making it easier for the microwaves to be emitted, so the heating efficiency can be improved accordingly. This has the effect of shortening the time required for cooking.

Note that the present invention is not limited to the above-mentioned embodiment, and other embodiments shown in FIGS. 4 and 5 may be used.

That is, in the second embodiment, a reflection plate 20 made of, for example, a metal plate is provided on the partition plate 13 that protects the rotating waveguide 6, and the microscopic light emitted from the excitation aperture 9 (or the second excitation aperture 10) is While reflecting the waves with the reflecting plate 2o,
The reflected waves from the peripheral wall of the heating chamber 2 are reflected again to disperse the microwaves more effectively.

Specifically, the reflector plate 20 is provided in a place where the electric field is strong, for example, in a part of the inner bottom surface of the partition plate 13 corresponding to the locus of the excitation aperture 9 on the bottom wall, and at this position, it reflects the microwaves emitted from the excitation aperture 9. In addition to being reflected (dispersed), the reflected waves from the peripheral wall of the heating chamber 2 are also reflected (dispersed) again. This kind of reflection of radio waves has the advantage that it can be used not only for downward direction of microwaves but also for heating chambers. Of course, the number of reflectors 20 that reflect radio waves is not limited to one, and it goes without saying that a plurality of reflectors may be used.

In addition, when installing the reflector plate 20, there is a concern that the partition plate 13 may melt due to the influence of the heat of the reflector plate 2 (4). , the ribs 21 are protruded from the inner bottom surface of the partition plate 13, the reflector 20 is arranged on the ribs 21, and the reflector 20 and the partition plate are welded to the ribs 21. An installation structure is adopted in which a heat insulating space 22 is provided between the heat shield and the heat shield 13, thereby suppressing the influence of heat and preventing the above problem. However, 23 is the welded part, and
The gaps between the two are shown respectively.

In addition, although a rectangular excitation aperture was used in all of the examples,
The shape is not limited, and other shapes may be used.

〔Effect of the invention〕

As explained above, according to the present invention, the irradiation direction is multidirectional, and at the same time, the object to be heated is directly irradiated with high frequency waves.
By using reflection (dispersion) on the heating chamber wall surface, it becomes possible to irradiate high frequency waves to parts of the object to be heated that are difficult to directly irradiate. In other words, it becomes possible to irradiate the object to be heated with high frequency waves from all directions.

As a result, the object to be heated can be uniformly irradiated with high frequency waves, and the object can be heated evenly. Moreover,
As the area of the excitation aperture increases, it becomes easier for microwaves to be emitted, which has the advantage of improving heating efficiency and shortening the time required for heating.

[Brief explanation of drawings]

Figures 1 to 3 show one embodiment of the present invention.
The figure is a front sectional view showing the high-frequency heating device, Figure 2 is a front sectional view showing an enlarged view around the rotating waveguide, Figure 3 is a perspective view showing the rotating waveguide, and Figures 4 and 5. 4 shows another embodiment of the present invention, FIG. 4 is a perspective view showing the structure around the rotating waveguide, FIG. 5 is a sectional view showing the installation structure of the reflecting plate provided on the partition plate, and FIG. 6 7 is a front sectional view showing a high frequency heating device employing a conventional rotating waveguide, and FIG. 7 is an enlarged front sectional view showing the area around the rotating waveguide. 2... Heating chamber, 5... Magnetron, 6... Rotating waveguide, 9... Excitation opening, 10... Second excitation opening. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (2)

[Claims] (1) A rotating waveguide having a vessel-like shape and an excitation opening formed in the bottom wall is provided in the heating chamber, and a high frequency wave is irradiated into the heating chamber from the excitation opening that rotates together with the rotating waveguide. A high-frequency heating device characterized in that a second excitation opening is provided in a peripheral wall of the rotating waveguide. (2) The high-frequency heating device according to claim 1, wherein there is a plurality of second excitation openings.