JPS6346553B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improving radio wave distribution within a heating chamber of a high frequency heating device.

Conventional configurations and their problems Conventionally, high-frequency heating devices have a turntable system that rotates the food table, a rotary antenna system that rotates the antenna that emits radio waves, and a rotary antenna system that rotates the antenna that emits radio waves. There are several methods, such as the Stara method, but in either case, the problem is that the heating of the central part of the food is usually weaker than the other parts.

In the case of the turntable method mentioned above, since the food itself rotates, it is easy to balance left and right or front and back, so it is possible to consider measures to strengthen the center, such as moving the power supply port slightly from the center. However, in the case of rotating antennas and starrer systems, it is very difficult to increase the heating in the center because the balance between left and right and front and rear is easily lost.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a high-frequency heating device that heats the central portion and has good radio wave distribution performance.

Structure of the Invention In order to achieve the above object, the present invention includes a heating chamber for storing food, a high frequency oscillator for supplying high frequency waves into the heating chamber, and a device for transmitting radio waves oscillated by the high frequency oscillator. a first radio wave emitting means that connects the transmission means and the heating chamber at approximately the center of one wall constituting the heating chamber; A configuration in which second and third radio wave emitting means are provided at a corner where two walls of the heating chamber intersect,
The second and third radio wave emitting means intensify the heating of the central part of the food that is difficult to be heated by the first emitting means,
Furthermore, by exciting the heating chamber in a mode in which the vertical electric field mode and the horizontal electric field mode are mixed, it is possible to make the radio wave heating distribution within the heating chamber uniform.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings.

In Figures 1 and 2, 1 is the main body;
There is a heating chamber 2 inside. A front opening of the heating chamber 2, which is provided for taking food in and out, can be opened and closed by a door 3. 4 is a high frequency oscillator,
The radio waves thus oscillated are transmitted by the waveguide 5, and are transmitted to the rotary antenna 8, which is a first radio wave radiating means, provided approximately at the center of the bottom wall 2a of the heating chamber 2, and to the bottom wall 2a of the heating chamber 2. The energy is radiated into the heating chamber 2 from the power feed ports 20 and 21, which are second and third radio wave radiating means, provided at the corner 2c where the side walls 2b intersect. The rotating antenna 8 consists of a vertical component 9 that is substantially perpendicular to the bottom wall 2a of the heating chamber 2 and a horizontal component 10 that is connected at a substantially right angle thereto.

The vertical component 9 of the rotating antenna 8 has a rotational drive axis 1.
2 is connected, and this is rotationally driven by a motor 16 via pulleys 13, 14 and a belt 15. 17 is a sealing plate for sealing the opening in the bottom wall 2a of the heating chamber 2 through which the vertical component 9 of the rotating antenna 8 passes. The radio wave supply space of the heating chamber 2, in which the rotating antenna 8 and the radio wave feed ports 20 and 21 are provided, and the heating space in which the food to be heated is stored are separated by a food mounting table 11 made of a dielectric material. . The radio wave supply space of the heating chamber 2 in which the radio wave power feed ports 20 and 21 are provided and the heating space in which the food to be heated is stored are separated by a food mounting table 11 made of a dielectric material. Corner 2c of heating chamber 2 where radio wave feed ports 20 and 21 are provided
The portion is inclined with respect to the bottom wall 2a and side wall 2b of the heating chamber 2, and the food mounting table 11 is supported at a portion 2d where this inclined surface intersects with the side wall 2b.

FIG. 3 shows a rotating antenna 8, a radio wave feeding port 20,
This is another embodiment in which the heating chamber 21 is provided at the upper part of the heating chamber 2. Reference numeral 22 denotes a top plate made of dielectric material and provided separately to partition the radio wave supply space.

The operation of the above configuration will be explained below.

The radio waves oscillated by the high-frequency oscillator 4 are transmitted through the waveguide 5 and radiated into the heating chamber 2 mainly from the horizontal portion of the rotating antenna 8 .

Normally, when radio waves are emitted only from the rotating antenna 8, when the rotating antenna 8 is located at the bottom 2a of the heating chamber 2, the center of the top of the food is
, the center of the food is difficult to heat, but the radio waves from the radio wave feed ports 20 and 21 provided at the corner 2c heat the parts that are difficult to heat by these rotating antennas 8, and the center of the food is difficult to heat. As a result, the entire food is heated evenly. In other words, when the radio wave supply space is located at the bottom 2a of the heating chamber 2 as shown in Figs. By the time it reaches , the heating has weakened considerably, and therefore the heating at the top, especially in the center, has weakened, but the proportion of radio waves from the radio wave feed ports 20 and 21 provided at corner 2c is directly absorbed by the food. Since most of the heat is reflected off the top wall and absorbed from the top of the food, it is possible to heat the top of the food, which is weak.

Conversely, when the radio wave supply space is located above the heating chamber, the distance between the rotating antenna 8 and the food is large, so the proportion of radio waves radiated from the rotating antenna 8 that is directly absorbed by the food gradually decreases. Most of the radio waves are reflected repeatedly on the walls of the heating chamber 2 and then absorbed mainly from the sides of the food, so that the heating in the center tends to be weak. However, if another radio wave power supply port 20, 21 is provided at the corner 2c, the proportion of the radio waves emitted from these ports directly reaching the center of the food increases, thereby increasing the heating of the center.

In addition, if the radio wave feed port is provided on a flat surface, the direction of the electric field inside the waveguide and the surface where the feed port is provided are 90 degrees apart, so the radio waves will pass through the feed port in the middle of the transmission path. The ratio of radio wave radiation from the power supply port near the end of the transmission path becomes extremely high, making it difficult to balance the left and right sides, but since the radio wave power supply ports 20 and 21 are provided at the corner 2c, The direction of the electric field and the direction of the radio wave feeding ports 20, 21 become closer, and the amount of radio waves radiated from the feeding port 21 on the way increases, making it easier to balance the left and right sides.

Furthermore, there are radio wave feeding ports 20 and 21 in the corner 2c part.
By providing this, a composite mode pattern can be obtained in which the electric field mode pattern when power is supplied from the top wall 2e or bottom wall 2a of the heating chamber 2 and the electric field mode pattern when power is supplied from the side wall 2b is synthesized. It is also possible to select a pattern of this composite mode in combination with the dimensions of , so that a portion that is weakly heated by the rotating antenna 8 can be heated.

Effects of the Invention As described above, according to the present invention, the following effects are obtained.

(1) Directly radiated radio waves from the radio wave feed port provided at the corner strengthen the heating of the center of the food, etc., which is difficult to be heated by the first radio wave radiating means.
Uniform heating distribution can be achieved.

(2) By bringing the surface of the radio wave feed port closer to the direction of the electric field inside the waveguide, it is possible to increase the radio wave radiation ratio from the power feed port provided in the middle of the transmission path.
This makes it possible to balance the amount of radio wave radiation on the left and right sides.

(3) Due to the combined electric field mode pattern of the electric field mode pattern when power is supplied from the top or bottom wall of the heating chamber and that when power is supplied from the side wall, it is possible to obtain an electric field pattern that cannot be obtained by conventional power supply only from horizontal or vertical surfaces. By selecting an appropriate mode in combination with the heating chamber dimensions,
The central rotating antenna can heat areas that are difficult to heat.

(4) When supplying power from the bottom wall of the heating chamber, by slanting the surface of the power supply port provided at the corner,
Since the food mounting table can be supported by the fulcrum between the inclined surface and the side wall, special metal fittings for supporting the food mounting table are not required, making it simple and cost-effective.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a high-frequency heating device that is an embodiment of the present invention, FIG. 2 is a sectional view of the same, and FIG. 3 is a front sectional view of a high-frequency heating device that is another embodiment of the present invention. It is. 1... Main body, 2... Heating chamber, 4... High frequency oscillator, 5... Waveguide, 8... Rotating antenna, 20,
21...Radio wave power supply port.

Claims (1)

[Scope of Claims] 1. A heating chamber for storing food, a high-frequency oscillator for supplying high-frequency waves into the heating chamber, a transmission means for transmitting the radio waves oscillated by the high-frequency oscillator, and the transmission means for transmitting the radio waves oscillated by the high-frequency oscillator. A first unit that connects the means and the heating chamber at approximately the center of one wall constituting the heating chamber.
and second and third radio wave emitting means provided at a corner where two walls of a heating chamber that are substantially symmetrical with respect to the first radio wave emitting means intersect. 2. Slant the corner part to the wall surface of the heating chamber,
The high-frequency heating device according to claim 1, wherein second and third radio wave radiating means are provided on the inclined surface. 3. The high-frequency heating device according to claim 1, wherein the food mounting table is supported at the intersection of the side wall and the inclined surface provided with the second and third radio wave emitting means.