JPS6240557Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in uniform heating of a high-frequency heating device that heats an object to be heated, such as food, using high-frequency energy.

Conventionally, in a high-frequency heating device in which an object to be heated is placed on a saucer made of a dielectric material, and the saucer is rotatably supported by a rotary table made of a metal disc, the rotary table is made of metal and thus reflects high frequencies. So,
It blocked high frequency waves entering from the bottom of the heated object. In addition, a hole as large as possible was made in the rotary table, and a high frequency wave was made to enter the bottom of the saucer through the hole, and after passing through the dielectric saucer, it was made to enter the bottom surface of the object to heat it. Things were hot too. However, in order to efficiently inject high frequency waves from the bottom surface of the object to be heated and to eliminate insufficient heating of the bottom surface of the object to be heated, it is necessary to appropriately select the shape, arrangement, etc. of the holes based on the principle of microwaves.

Therefore, an object of the present invention is to provide a means for efficiently guiding the high frequency waves that have entered the lower part of a metal rotary table to the lower surface of the object to be heated, thereby resolving the insufficient heating of the lower surface of the object to be heated.

Next, an embodiment of the high frequency heating device of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a high frequency oscillator that generates high frequency waves. 2 is a waveguide that transmits high frequency waves,
A high frequency oscillator 1 and a heating chamber 3 are connected. 4
is a saucer on which the object to be heated 5 is placed, and is made of a dielectric material. The saucer 4 is rotatably supported by a rotating table 6. The rotating table 6 has a plurality of bow-shaped slots 6a.
It consists of a metal disc with a 6b is a rotating shaft of the rotary table 6, which is made of a metal pipe. 7 is a drive shaft detachably connected to the rotating shaft 6b, which is made of a metal rod;
It is coupled to a motor or pulley (not shown).

FIG. 2 is a top view of the rotary table 6 viewed from above.
The plurality of arcuate slots 6a are arranged along the same circumferential direction, and the length L of the circular arc indicated by the arrow is approximately 1/2 of the wavelength λ used (in practical terms, it is 1/2 λ to 1/2 λ+λ).
/6 is good). Therefore, the bow-shaped slot 6a functions as a well-known slot antenna, and efficiently transmits the high frequency waves that have entered the lower part of the rotary table 6 to the upper part of the rotary table 6. The high frequency waves entering the bow-shaped slot 6a are repeatedly reflected, transmitted, and refracted by the dielectric saucer 4 and the top surface of the metal rotary table 6, as shown by the arrows in FIG. be guided.

Since the rotating shaft 6a and the driving shaft 7 of the rotating table 6 are made of metal, the high frequency waves that enter from the periphery of the rotating table 6 toward the center are reflected by the metal surfaces of the rotating shaft 6b and the driving shaft 7, and heat the rotating table 6. A standing wave is generated between the chamber 3 and the bottom surface of the chamber 3. It is assumed that the current value of the standing wave reaches its maximum on the metal surface of the rotating shaft 6b, and reaches its maximum again at a distance of 1/2λ. Therefore, if the distance A between the bow-shaped slot 6a and the metal surface of the rotating shaft 6b is set to approximately 1/2λ, the current cut by the bow-shaped slot 6a will be maximized, so that the high frequency waves that have entered the lower part of the rotating table 6b will be It can be guided to the lower surface of the heated object 5 through the slot 6a more efficiently.
To solve insufficient heating of the lower surface of the object to be heated 5. Practically speaking, A is preferably about 1/2λ±λ/6. Furthermore, since the bow-shaped slots 6a are arranged along the same circumferential direction of the rotary table 6, the high frequency waves that enter the lower surface of the object to be heated 5 through the bow-shaped slots 6a are also on the same circumference, so there is less uneven heating. Become.

As described above, according to the high frequency heating device of the present invention, the bow-shaped slot 6a provided in the rotary table 6 functions as an antenna, and the high frequency waves that have entered the lower part of the rotary table 6 are efficiently guided to the lower surface of the object to be heated 5. Even when the dielectric saucer 4 is rotatably supported by the metal turntable 6, the lower surface of the object to be heated 5 is not insufficiently heated, and uneven heating can be reduced, and the implementation effect is great. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of the high-frequency heating device of the present invention, and FIG. 2 is a top view of the rotary table 6 of FIG. 1 viewed from above. DESCRIPTION OF SYMBOLS 1...High frequency oscillator, 4...Saucer, 5...Heated object, 6...Rotating table, 6a...Archive-shaped slot.

Claims (1)

[Claims for Utility Model Registration] In a high-frequency heating device in which an object to be heated is placed on a saucer made of a dielectric material, and the said saucer is rotatably supported by a rotary table made of a metal disc, the length of the circular arc A high-frequency heating device characterized in that a plurality of arcuate slots 6a whose length L is approximately 1/2 of the wavelength used are scattered along the circumferential direction of the rotary table 6.