JPS61292890A - 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 particularly relates to an improvement of a high-frequency heating device in which a rotating waveguide is provided in a heating chamber.

[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. 7 and 8 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 in the upper part of the heating chamber C to generate a magnetron d (oscillation). In addition to being able to receive microwaves oscillated from a heating chamber C, a structure is used in which a rotating waveguide is connected to a motor (driver S) placed outside the heating chamber C. The microwave is heated from the excitation aperture a that rotates as the
It was irradiating inward. In addition, f is mag-netron d
A waveguide is shown for guiding microwaves oscillated from a rotating waveguide to a rotating waveguide.

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.

Especially when cooking a large-sized food Q, or heating the food Q 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, the present invention forms the excitation opening of the rotating waveguide from the bottom wall to the circumferential side wall, thereby making the irradiation directions multidirectional, and simultaneously irradiating the object to be heated with high frequency waves.
The purpose is to irradiate high frequency waves to parts of the heated object that are difficult to irradiate by using reflections from the walls of the heating chamber.

(Embodiments of the Invention) The present invention will be described below based on a first embodiment shown in Figs. 1 is a main body, 2 is a heating chamber provided in the main body 1, 3 is an excitation opening provided in the upper wall of the heating chamber 2, and 4 is a magnetron (compatible with the oscillation device of the present invention) on one end side. The 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, and the waveguide 4 is connected to the opening 3, and the waveguide 4 is connected to the opening 3. Microwaves (high frequency waves) can be supplied to the heating chamber 2.

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 an excitation opening 9 is provided at the other end on the opposite side. There is. The excitation opening 9 includes a rectangular first opening 9a provided in the bottom wall on the other end side of the waveguide main body 7 along the width direction, and extends from the center of the first opening 9a to the other adjacent end. A second opening 9b with a smaller opening width is provided over the side peripheral wall portion, and the entire communicating openings 9a and 9b serve as an excitation opening. The rotating waveguide 6 is arranged on the upper side of the heating chamber 2 so that the opening faces the opening 3, and
This allows it to receive microwaves emitted from the

On the other hand, 10 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 10a of this motor 10 extends through the waveguide 4 to just below the opening 3. As shown in FIG.
1, and the rotating waveguide 6 can be eccentrically rotated using the motor 10 as a driving source.

Of course, the opening of the rotating waveguide 6 is large enough to accommodate the entire opening 3.

In FIG. 1, reference numeral 12 denotes a partition made of a material with excellent radio wave transparency, such as heat-resistant plastic, provided to cover the periphery of the rotating waveguide 6 and to protect the rotating waveguide 6. It is a board.

Next, the operation of the microwave oven configured as described above will be explained. Now, there are 13 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 5I5 and the motor 10 to operate. Then, microwaves are oscillated from the magnetron 5 and guided to the rotating waveguide 6 through the waveguide 4° opening 3.

Microwaves are then irradiated into the heating chamber 2 from the excitation opening 9 .

Here, it has been pointed out that conventionally, heating unevenness occurs because microwaves are not uniformly irradiated onto the food 13 to be cooked, but according to the present invention, heating unevenness can be eliminated.

That is, according to the present invention, the excitation opening 9 is provided extending from the bottom wall of the rotating waveguide 6 to the circumferential side. This means that the microwave from the opening 9a on the bottom wall side of the rotating waveguide 6 is
As shown by A in the figure, it is emitted downward (directly below),
The upper part of the food 13 to be cooked is irradiated directly. Also, the rotating waveguide 6
The microwaves from the opening 9b on the peripheral wall side of the heating chamber 2 are emitted to the peripheral wall of the heating chamber 2 as shown by 8 in FIG. Irradiates areas such as the surrounding area. However, the microwaves are uniformly irradiated on both the upper and peripheral parts of the food 13 to be cooked. Moreover, the reflected microwaves are transferred to the heating chamber 2.
Since the radiation is applied from the periphery of the heating chamber 2, even if the food 13 is large, or if the food 13 is placed toward the corner of the heating chamber 2, the entire surface will be uniformly irradiated. As a result, it can be seen that all parts of physical object 11 are uniformly irradiated with microwaves. Therefore, heating can be performed without uneven heating. Moreover, the excitation aperture 9 compared to the conventional one
As the area becomes larger, it becomes easier for microwaves to be emitted, so heating efficiency can be improved accordingly, and there is also the advantage that the time required for heating and cooking can be shortened.

Furthermore, the present invention is not limited to the first embodiment described above, but can be applied to the second embodiment shown in FIG. 4, FIGS. 5 and 6.
The third embodiment shown in the figure may also be used.

That is, in the second embodiment, second openings 9b, which have the same opening width as the first opening 9a and communicate with the first opening 9a, are provided in two peripheral walls adjacent to the end of the first opening 9a. and constitute an excitation opening 9 extending from the bottom wall to the peripheral wall,
Even in this case, the same effect as in the first embodiment can be obtained.

Third. In this embodiment, as shown in FIG. 5, a stepped portion 20 is integrally formed with the waveguide main body 7 on the other end side of the bottom wall of the rotating waveguide 6 by pressing (in the case of a metal plate, etc.). An excitation opening 9 similar to that of the first embodiment is formed on the bottom wall of this stepped portion 20.
It has been established.

In such a rotating waveguide 6, as shown in FIG. 6, the microwave emitted to the rotating waveguide 6 is reflected in an undefined direction at the stepped portion 20, and then is irradiated into the heating chamber 2 through openings 9a and 9b. Therefore, compared to the first and second embodiments, this embodiment has the advantage that microwaves can be irradiated in multiple directions (all directions). It goes without saying that the depth, width, etc. of the stepped portion 2o are set such that the best radio wave power feeding efficiency (with respect to the heating chamber 2) can be obtained.

Moreover, the stepped portion 20 not only has the function of irradiating the microwave in an undefined direction into the heating chamber 2, but also has the function of irradiating the microwave into the heating chamber 2 in an undefined direction.
It has the advantage of increasing the rigidity and preventing deformation (due to the effects of rotation, etc.), and improving reliability by eliminating the generation of sparks due to electric field concentration caused by deformation.

〔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 from 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.

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 the drawing]

1 to 3 show a first embodiment of this invention,
Figure 1 is a front sectional view showing the high-frequency heating device, Figure 2 is a front sectional view showing an enlarged view of the rotating waveguide, Figure 3 is a perspective view of the rotating waveguide, and Figure 4 is a front sectional view showing the rotating waveguide. A perspective view showing a different rotating waveguide according to a second embodiment of the invention, FIGS. 5 and 6 showing a third embodiment of the invention, and FIG. 5 a perspective view showing a rotating waveguide; Fig. 6 is a front cross-sectional view showing the rotary waveguide arranged in the heating chamber, Fig. 7 is a front cross-sectional view showing a high-frequency heating device using a conventional rotating waveguide, and Fig. FIG. 3 is an enlarged front cross-sectional view showing the area around the rotating waveguide. 2... heated seedlings, 5... magnetron (oscillation device),
6... Rotating waveguide, 9... Excitation opening, 20... Step portion. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 5

Claims (2)

[Claims] (1) A heating chamber, an oscillation device that supplies high frequency waves to the heating chamber, and an excitation opening that is provided in the heating chamber and that receives the high frequency waves oscillated from the oscillation device and irradiates the inside of the heating chamber, extending from the bottom wall to the peripheral wall. A high-frequency heating device characterized by comprising a vessel-shaped rotating waveguide formed with a bridge. (2) The high-frequency heating device according to claim 1, wherein the rotating waveguide has a stepped portion formed on the bottom wall.