JPS6212640B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency heating device, a so-called household microwave oven, which not only aims to make the electric field distribution uniform, but also has a high-frequency output for food as small as 100g, with a water load of 2. The present invention provides an efficient high-frequency heating device that can produce the same amount of heat and also has no temperature difference between the top and bottom even when dealing with vertically long loads such as Choshi.

Conventionally, there have been various methods for uniform heating using high-frequency heating devices, and the main ones include a stirrer method and a turntable method, and there are also methods that combine these two methods.

Furthermore, there are various other methods, but for vertically long loads such as Choshi, there will be a temperature difference between the top and bottom, and the high frequency output of about 100g will only be about 75% of the output when loaded with two water. Therefore, even if a microwave oven has an output of 600W, if the actual load is small, it will be heated with an output of about 450W, which is very inefficient.

Therefore, the present invention solves the above-mentioned conventional drawbacks with a simple configuration, and embodiments of the present invention will be described below.

In FIG. 1, high-frequency radio waves from a magnetron 1 pass through a waveguide 2, are fed to an antenna 4 rotated by a motor 3, and are radiated into a heating chamber 5 to heat food. Reference numeral 6 denotes a table on which food is placed, and is made of a material with low high frequency loss. Note that waveguide 2
The heating chamber 5 is communicated with a small hole H having a wavelength of less than 1/2 of the radio wave used, and an antenna 4 is rotatably provided through this small hole H.

The antenna 4 is made of a 2 mm thick metal plate, and on the side of the heating chamber 5 there are two horizontally arranged antennas at different heights.
It has book radiation sources 7 and 8, and a triangular part 9 for adjusting the ratio of radio wave radiation amount of these two radiation sources.
have. (Refer to Figure 2) Experiments using a high-frequency heating device equipped with an antenna with the above configuration revealed that the radio wave radiation source rotated, which resulted in uniformity. Very good results were obtained, with the temperature difference between the top and bottom of the heated object being within 2°C. It was also found that the high-frequency output of food weighing about 100g reaches about 90% of the output when water is loaded in step 2, meaning that a 500W output microwave oven can cook food in about the same time as a conventional 600W output microwave oven, and consumes less power. It was found that it was possible to reduce the

FIG. 3 shows another embodiment of the present invention, in which a metal reflector plate 10 is provided on both sides of the antenna 4, and a support rod 11 made of a low-loss dielectric material is used to fix the position.
The antenna 4 and the metal reflector 10 are fixed.
Further, the metal reflecting plates 10 on both sides of this antenna 4 are connected to each other by a metal plate.

According to experiments, it was found that by attaching the metal radiation plate 10 to the antenna 4, higher performance than the antenna distribution performance described above can be obtained.

The embodiment shown in FIG. 4 has a configuration in which an impeller 12 made of a low-loss dielectric material is attached integrally with the antenna 4 in order to rotate the antenna 4 with cooling air from a magnetron.

FIG. 5 is a perspective view of the impeller 12 and antenna 4 of FIG. 4. Reference numeral 13 denotes a blower for cooling the magnetron. After cooling the magnetron 1, cooling air is introduced into the heating chamber 5, and is applied to the impeller 12 to blow the cooling air to the antenna 4.
It rotates and drives.

As explained above, according to the present invention, the electric field distribution can be improved with a simple configuration, and the efficiency of high frequency output at light loads can be increased.

Furthermore, it is possible to provide a highly efficient high-frequency heating device that is extremely user-friendly and has almost no temperature difference between the top and bottom of a vertically long food.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a high-frequency heating device showing one embodiment of the present invention, FIG. 2 is a perspective view of the main part of the antenna, and FIG. 3 is a perspective view of another embodiment of the same antenna.
FIG. 4 is a longitudinal sectional view of another embodiment of the present invention, and FIG. 5 is a perspective view of the main antenna section. 1... Magnetron, 2... Waveguide, 3... Motor, 4... Antenna, 5... Heating chamber, 6...
Base, 7, 8...Radiation source, 10...Metal reflector, 1
2... Impeller.

Claims (1)

[Claims] 1. The configuration is such that high-frequency electromagnetic waves from a high-frequency oscillator are sent into the heating chamber through a waveguide, and the waveguide communicates with the heating chamber at the bottom of the heating chamber through a small hole of 1/2 wavelength or less. A rotatable antenna is provided at the center of the hole, and the antenna is provided with a plurality of metal conductors at different intervals from the heating chamber wall parallel to the heating chamber wall in which the small hole is provided, and the rotation of the metal conductor and the antenna is A high-frequency heating device with an appropriate triangular section at the joint with the shaft. 2. The high-frequency heating device according to claim 1, wherein the antenna is configured to have a flattened shape. 3 High-frequency electromagnetic waves from a high-frequency oscillator are sent into the heating chamber through a waveguide, and the waveguide communicates with the heating chamber through a small hole of 1/2 wavelength or less at the bottom of the heating chamber. A flexible antenna is provided, and the antenna is provided with a plurality of metal conductors at different intervals from the heating chamber wall parallel to the heating chamber wall provided with a small hole, and at the joint between the metal conductor and the rotating shaft portion of the antenna. A high-frequency heating device comprising a triangular portion as appropriate, a plurality of electromagnetic wave reflecting plates rotating coaxially with an antenna at positions facing the metal conductor, and electrically connecting the plurality of electromagnetic wave reflecting plates to each other. 4 High-frequency electromagnetic waves from a high-frequency oscillator are sent into the heating chamber through a waveguide, and the waveguide communicates with the heating chamber through a small hole of 1/2 wavelength or less at the bottom of the heating chamber. A flexible antenna is provided, and the antenna is provided with a plurality of metal conductors at different intervals from the heating chamber wall in parallel with the heating chamber wall provided with a small hole, and the antenna is equipped with a low-loss dielectric material for wind drive. A high-frequency heating device equipped with an impeller.