JPS6115587Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to an improvement of a high-frequency heating device in which a rotating disk formed by disposing a metal piece on a substrate made of a low dielectric material and forming an excitation port is provided at a high-frequency reception port of a heating chamber. Figures 1 and 2 show a conventional high-frequency heating device;
For example, it shows the general configuration of the entire microwave oven.
1 is the main body. A heating chamber 2 and a magnetron (high frequency oscillator) 3 are housed within the main body 1. A circular high-frequency reception port 4 is provided in the ceiling plate 2a of the heating chamber 2, and a cavity box 5 is attached to the ceiling plate 2a so as to cover the high-frequency reception port 4 from above. This cavity box 5 is connected to a connecting portion 6 that guides the high frequency waves output from the magnetron 3, and together with this connecting portion 6 constitutes a waveguide. Further, the high-frequency reception port 4 of the heating chamber 2 is provided with a rotating disk 7 that is slightly smaller than the high-frequency reception port 4 . The rotating disk 7 is composed of a circular substrate 8 made of a low dielectric material and four fan-shaped metal pieces 9 disposed on the substrate 8. Each of these metal pieces 9... are arranged at predetermined intervals, and a substantially cross-shaped excitation opening 10 is formed by the gap between each metal piece 9. This rotating disk 7 is connected to a rotating shaft 1 attached to the cavity box 5.
is rotatably supported by 1, and
A wind receiver (not shown) is installed on the upper surface, and cooling air for cooling the magnetron 3 is transmitted to the cavity box 5.
It is designed to be guided into the air and rotated by this cooling air. The high frequency waves output from the magnetron 3 are guided to the high frequency receiving port through the waveguide, and are substantially totally reflected on the surface of each metal piece 9, mainly at the excitation port 10.
Since the excitation port 10 is rotated as the rotating disk 7 rotates, the distribution of the high frequency energy introduced into the heating chamber 2 can be adjusted to a favorable state. It is becoming possible to do this. By the way, since the rotating disk 7 is driven to rotate, the peripheral portion 2b of the high frequency reception port 4 of the heating chamber 2
A ring-shaped gap 12 is formed between the rotary disk 7 and the rotary disk 7, and the high frequency waves guided into the cavity box 5 may leak into the heating chamber 2 through this gap 12. Ta. In this case, the intensity of the high frequency wave guided into the heating chamber 2 through the gap 12 differs depending on the distance from the magnetron 3. For example, as shown in FIG. 3, the gap between a portion A near the magnetron 3 and a portion B far from the magnetron 3 in the gap portion 12 is approximately (λ/2×n) (λ is the high frequency output from the magnetron 3). When the wavelength is approximately 120 mm (n is an integer), the high frequency wave guided into the heating chamber 2 from part A near the magnetron 3 is
The high frequency wave is stronger than the high frequency wave guided into the heating chamber 2 from the part B which is far from the area B. Therefore, there is a problem that the distribution of the high frequency energy guided into the heating chamber 2 becomes uneven, and there is a drawback that the food placed in the heating chamber 2 is not heated uniformly. This idea was made in consideration of the above circumstances, and its purpose is to be able to adjust the distribution of high-frequency energy introduced into the heating chamber to a favorable state.
An object of the present invention is to provide a high-frequency heating device that can uniformly heat food and the like placed in a heating chamber. An example of this invention is shown below in Figures 4 and 5.
This will be explained with reference to the figures. Figure 4 shows the main structure of a high-frequency heating device, such as a microwave oven.
Components that are the same as those in FIGS. 1 to 3 are given the same reference numerals, and their explanations will be omitted. That is, in this invention, the rotating disk 7 is arranged eccentrically with respect to the high-frequency receiving port 4 of the heating chamber 2, and the gap formed between the peripheral portion 21 of the high-frequency receiving port 4 of the heating chamber 2 and the rotating disk 7 is This is characterized in that the width of the portion 22 is non-uniform. Here, the distance between a portion of the gap 22 where the high frequency is most strongly introduced into the heating chamber 2, for example, a portion A of the gap 22 closest to the magnetron 3 and a portion B farthest from the magnetron 3 is (λ/2 × n), the center of rotation O of the rotating disk 7 is moved toward the magnetron 3 by an appropriate eccentric distance S from the center O of the high-frequency reception port 4 so that the width dimension of the portion A closest to the magnetron 3 is narrowed. The rotating disk 7 is arranged with its point eccentrically centered. Therefore, in the case of the above configuration, the high frequency output from the magnetron 3 is guided into the cavity box 5, and most of the high frequency waves output from the magnetron 3 are introduced into the excitation port 1 of the rotating disk 7.
0 into the heating chamber 2. Also, a part of the high frequency wave guided into the cavity box 5 is transmitted to the heating chamber 2.
is introduced into the heating chamber 2 through the gap 22 between the peripheral edge portion 21 of the high-frequency reception port 4 and the rotating disk 7 . In this case, the width of the gap 22 is narrow at a portion A where the high frequency is introduced into the heating chamber 2 with a strong force, and the width of the portion B where the high frequency is weakly introduced into the heating chamber 2 is wide. The high frequency energy introduced into the heating chamber 2 through the portion 22 can be adjusted to be substantially uniform. The applicant confirmed this through the following experiment. In FIG. 5, reference numeral 23 denotes a shelf board placed in the heating chamber 2, and the horizontal dimension of this shelf board 23 is W, and the depth dimension is D. In addition, five containers 24a to 24e each containing 100 c.c. of water are prepared, and first, the container 24a is placed in the center of the shelf board 23, and this container 2
Four containers 24b to 24e are respectively arranged at positions with an interval of W/4 on both sides of the container 4a in the lateral direction and an interval of D/4 on both sides of the container 4a in the depth direction. In this state, operate the magnetron 3 for 2 minutes and
Check the temperature rise value of the water in 4a to 24e. Heating chamber 2 is determined from the ratio (water distribution ratio) of the minimum temperature rise value (MIN rise value) and the maximum temperature rise value (MAX rise value).
The purpose of this method is to investigate the distribution of high-frequency energy introduced into the system. Here, water distribution rate () = MIN increase value / MAX increase value × 100
(%) Then, under the same conditions, experiments were conducted with the conventional configuration (when the width of the gap portion is uniform) and the configuration of the present invention (when the width of the gap portion 22 is uneven). The experimental results are shown in the table. (Number of samples n=3)

[Table] As is clear from this table, the water distribution ratio ( ) of the structure of the present invention is larger than that of the conventional structure, so the temperature rise of the water in each container 24a to 24e is It can be seen that the variation is small. Therefore, when the width of the portion A of the gap 22 that is closest to the magnetron 3 is narrowed, the high frequency energy introduced into the heating chamber 2 from the high frequency reception port 4 is distributed more uniformly than before. become. Thus, the rotating disk 7 is arranged eccentrically with respect to the high-frequency receiving port 4 of the heating chamber 2, and the gap 22 formed between the peripheral portion 21 of the high-frequency receiving port 4 of the heating chamber 2 and the rotating disk 7 is Since the width dimension was made uneven,
Among the high-frequency waves introduced into the heating chamber 2 from inside the cavity box 5, the distribution of high-frequency energy can be adjusted to be substantially uniform even when the high-frequency waves pass through the gap 22.
By stabilizing the impedance and output of the high frequency wave guided into the heating chamber 2, it is possible to heat food, etc. placed in the heating chamber 2 substantially uniformly. It should be noted that this invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the invention. As explained above, this invention provides a high-frequency heating device in which a rotating disk, which is made of a substrate made of a low dielectric material and has a metal piece forming an excitation port, is arranged at the high-frequency receiving port of the heating chamber. The rotating disk is arranged eccentrically with respect to the high frequency reception port of the heating chamber,
The present invention is characterized in that the width of the gap formed between the peripheral edge of the high-frequency reception port of the heating chamber and the rotating disk is made non-uniform. Therefore,
With a simple configuration, the high-frequency energy introduced into the heating chamber through the gap can be adjusted to a uniform state among the high-frequency waves introduced into the heating chamber through the high-frequency receiving port. The distribution can be adjusted to a good state, and food products placed in the heating chamber can be uniformly heated, which is an excellent practical effect.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional examples.
The figure is a plan view showing the overall general configuration, and Figure 2 is the first
Figure 3 is a cross-sectional view taken along the - line in Figure 2, Figures 4 and 5 show an embodiment of this invention, and Figure 4 is a cross-sectional view showing the configuration of the main parts. FIG. 5 is a plan view showing the arrangement of containers on the shelf board. 2... Heating chamber, 3... Magnetron (high frequency oscillator), 4... High frequency reception port, 5... Cavity box (waveguide), 6... Connection part (waveguide), 7... Rotating circle Plate, 8...Substrate, 9...Metal piece, 10...Excitation port, 22...Gap portion.

Claims (1)

[Claims for Utility Model Registration] (1) The high frequency waves output from the high frequency oscillator are guided into the heating chamber through a waveguide, and a metal piece is placed on a substrate made of a low dielectric material to form an excitation port. In the high-frequency heating device, the rotating disk is disposed at the high-frequency receiving port of the heating chamber, and the rotating disk is arranged eccentrically with respect to the high-frequency receiving port of the heating chamber, and the peripheral portion of the high-frequency receiving port of the heating chamber is A high-frequency heating device characterized in that the width of the gap formed between the rotary disk and the rotary disk is made non-uniform. (2) The utility model registration claim described in item (1) is characterized in that the rotating disk is arranged at the high-frequency reception port of the heating chamber so that the width of the gap in the area where the high-frequency distribution is strong is narrowed. high frequency heating device.