JPS6220675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a high-frequency heating apparatus in which two shelves for placing objects to be heated are installed in a heating chamber, one above the other, in order to simultaneously perform high-frequency heating on a large amount of objects to be heated.
This is to reduce uneven heating between the upper and lower stages.

In conventional high-frequency heating devices, it is common to install one shelf near the bottom of the heating chamber on which the object to be heated is placed. In this case, since there is only one shelf, in order to heat treat a large amount of objects to be heated, it is necessary to heat the objects several times, which is time-consuming. Therefore, as a means to increase the amount of heat processed in one heating chamber, it is possible to install two stages of mounting shelves in the heating chamber, but the heating unevenness between the upper and lower stages is large, making it impossible to finish the two stages at the same time. There was a drawback.

Therefore, the present invention provides radiation sources (for example, rotating antennas) that radiate high-frequency energy into the heating chamber at the upper and lower parts of the heating chamber, and a transmission path within the waveguide from the radiation sources to the antenna section of the high-frequency oscillator. The above-mentioned drawbacks are attempted to be overcome by appropriately selecting the distance between the radiation source and the object to be heated.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high-frequency heating device of the present invention will be described below with reference to drawings.

The configuration of the embodiment is as shown in the figure. Reference numeral 1 denotes a high-frequency oscillator that generates high-frequency energy, and a radiation source 4a of a rotating antenna that radiates high-frequency energy into the heating chamber 3 through a U-shaped waveguide 2. 4b is supplied with high frequency energy. The rotation axis of the upper radiation source 4a is a metal shaft 5 passing through the center of the upper surface of the heating chamber 3.
a, and a dielectric drive shaft 6a that passes through the waveguide 2.
It is formed from. The rotation axis of the lower radiation source 4b is a metal shaft 5b passing through the center of the lower surface of the heating chamber 3,
It is formed from a dielectric drive shaft 6b that passes through the waveguide 2. Note that the radiation sources 4a and 4b are formed in the same manner and have the same high-frequency radiation pattern. 7a A shelf on which the object to be heated 8a is placed, and is made of a dielectric material that is transparent to high frequencies. Similarly to 7a, 7b is a shelf on which the object to be heated 8b is placed, and is made of a dielectric material that is transparent to high frequencies. The mounting shelves 7a and 7b are held at the upper and lower stages in the heating chamber 3 by shelf supports 9a and 9b, respectively. The distance A between the upper radiation source 4a and the upper mounting shelf 7a is λ/20 to λ/2 longer than the distance B between the lower radiation source 4b and the lower mounting shelf 7b.
(λ: wavelength of high frequency). Further, the antenna section 1a of the high-frequency oscillator 1 is attached to the vertical center of the U-shaped waveguide 2, or at a position an integral multiple of 1/2 of the guide wavelength from the center. That is, the transmission path lengths a and b in the waveguide from the antenna part 1a of the high-frequency oscillator 1 to the rotating antenna of the upper radiation source 4a or the attachment part of the lower radiation source 4b
In this case, a and b are made equal, or the difference between a and b is configured to be an integral multiple of 1/2 of the tube wavelength.

Next, the operation of the high frequency heating device of the present invention will be explained. When the high-frequency energy generated from the high-frequency oscillator 1 is supplied to the upper and lower radiation sources 4a and 4b via the waveguide 2, each radiation source 4a and 4b emits high-frequency energy to Objects 8a and 8b are dielectrically heated. When the rotating antennas of the radiation sources 4a and 4b have the same shape and dimensions, and the distance A is made larger than B by λ/20 to λ/2, it is confirmed that the heating patterns of the heated objects 8a and 8b almost match. has been done. Furthermore, high frequency oscillator 1
When the antenna section 1a is installed at the center of the waveguide 2, or at a position an integral multiple of 1/2 of the guide wavelength from the center, the load condition when looking upward from the antenna section 1a and the load condition when looking down from the antenna section 1a are approximately the same. Since they are equal, the radiation source 4
The amount of high frequency energy radiated from a and 4b becomes equal. Therefore, the objects to be heated 8 in the upper and lower stages
There is little uneven heating between a and 8b, and they are finished at the same time.

As described above, according to the present invention, the radiation sources 4a and 4b are provided above and below the heating chamber 3, and the mounting shelves are installed in two stages, the upper radiation source 4a and the upper mounting shelf 7a.
The distance A between the lower radiation source 4b and the lower mounting shelf 7b is made larger by λ/20 to λ/2, and the radiation sources 4a and 4b are made to have the same shape and the same radiated power. Therefore, the upper and lower heated objects 8a, 8
(b) There is little heating unevenness between each other, the upper and lower surfaces can be finished at the same time, and a large amount of objects to be heated can be easily heat-treated. Furthermore, the present invention allows a large area for placing the heated object relative to the floor area of the high-frequency heating device itself, so it can be used not only for commercial purposes such as restaurants and snack cafes with particularly small cooking areas, but also for home use. It is an easy-to-use high-frequency heating device that does the work of two machines.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the high frequency heating device of the present invention. 3...Heating chamber, 4a, 4b...Radiation source (rotating antenna), 7a, 7b...Placement shelf, 8a, 8b...
...Object to be heated.

Claims (1)

[Claims] 1 Radiation sources 4 having the same shape and emitting the same high-frequency power at the upper center and lower center of the heating chamber 3, respectively.
a, 4b are provided, and objects to be heated 8a, 8 are placed in the heating chamber 3.
The mounting shelves 7a and 7b on which the rays b are placed are installed in two stages, upper and lower, and the distance A between the upper radiation source 4a and the upper mounting shelf 7a is
, the distance B between the lower radiation source 4b and the lower mounting shelf 7b
A high-frequency heating device characterized in that it is larger by an amount equivalent to λ/20 to λ/2 (λ = wavelength of high frequency).