JPS60241696A - High frequency heating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improving radio wave distribution in a high frequency power Ω thermal device using a rotating radio wave radiator.

Conventional configurations and their problems A variety of methods have been proposed and implemented in attempts to make the radio wave distribution uniform in the heating chamber by rotating the radio wave radiator, but various methods have been proposed and implemented. , it has been found that the most effective method to have a stable effect on heating chambers of different shapes is to rotate a radio wave emitter with a strong radio wave radiation direction, such as a waveguide, at the bottom of the heating chamber. ing. Various rotating antennas, such as a rod-shaped antenna bent into an L-shape, have been proposed and are actually being implemented, but the biggest problem in these cases is that they provide directivity for radio wave radiation. Therefore, even if the antenna was rotated, the rotation effect was small and a good radio wave distribution could not be obtained.

On the other hand, in the case of waveguides as shown in Figures 1 and 2, the radiation directivity is very strong, so the rotation effect is very good, but the strong directivity causes another problem. . In other words, the electric field at the radiation opening 17 of the waveguide 9 is very strong, so in order to prevent it from directly hitting the food, the shape of the waveguide is formed from the center of rotation as shown in Figure 2. It is necessary to install the radiation port as far away as possible and close to the edge of the heating chamber.

However, in this case, although the radio wave distribution toward the ends of the heating chamber is improved, there is a problem in that the heating near the center becomes weaker.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and it is an object of the present invention to provide a radio wave feeding structure for a rotating waveguide system that solves the heating unevenness in the central portion and has a good distribution of radio wave heating.

Structure of the Invention In order to achieve the above object, the present invention includes a heating chamber, a high-frequency oscillator, and a rotating radiator that radiates -C-transmitted radio waves into the heating chamber through a waveguide, and the rotating radiator is simple. By combining the waveguide with the parallel plate line, the directivity of the waveguide is relaxed and the leakage of radio waves from the sides is actively prevented. By increasing the number, the heating in the center can be strengthened, and the overall radio wave distribution can be made more uniform.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, numeral 1 denotes a main body with a heating chamber 2 therein, and numeral 3 denotes a door that allows the front opening of the heating chamber to be opened and closed.

In FIG. 4, reference numeral 4 denotes a high frequency oscillator, and the radio waves oscillated by this are transmitted through a waveguide 5 and radiated into the heating chamber by a rotating radiator 6 provided approximately at the center of the bottom of the heating chamber. As shown in a perspective external view in FIG. 5, the rotating radiator is composed of a coaxial section 7 and a radiating section 8, and the radiating section 8 is further composed of a waveguide section 9 and a parallel plate line section 1o. The coaxial portion 7 is connected to a drive shaft 12 of a motor 11. Reference numeral 13 denotes a rail made of a low-loss dielectric material, on which the flange portion of the radiating section 8 slides and rotates, thereby maintaining a constant distance between the bottom wall of the heating chamber and the radiating section. 14 partitions the heating chamber into a radio wave supply section 16 where a rotating radiator is located and a heating section 16;
It is also a food mounting table for placing food and is made of a heat-resistant dielectric material.

FIG. 6 is a schematic diagram of another embodiment of the rotating radiator, in which the radiating section is constructed by sandwiching a parallel plate line section 1o between a waveguide section 9 and a waveguide section 9'.

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 6, excited by the coaxial section 7 of the rotating radiator 6, enter the heating chamber, and are further radiated into the heating chamber by the radiator 8. Since the first part of the waveguide consists of a waveguide, the direction of the radio wave propagation is very well controlled towards the open end of the waveguide.

However, at the tip of the waveguide, the side wall disappears and the line becomes a parallel plate line, so some of the radio waves that have been controlled and transmitted in one direction are now radiated from the side, causing food damage. Increase the heating near the center of the Also, the radio waves transmitted along the parallel plate line to the tip of the radiating section are radiated toward the top of the heating chamber from between the tip of the radiating section and the wall of the heating chamber, and are reflected by the side walls and earthen walls of the heating chamber. It mainly heats the outer periphery of the food.

By changing the position of the parallel plate line in the radiating section as shown in Figure 6, it is possible to adjust the heating balance between the center and the outer periphery of the food.

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

(1) By configuring the radiation section by a combination of a waveguide section and a parallel plate line, it is possible to intensify the heating near the center of the heating chamber and improve the radio wave heating distribution throughout the heating chamber.

(2) By using parallel plate tracks, the weight of the entire radiator group can be reduced, the friction between the rotating radiator and the rail during rotation can be reduced, and durability can be improved.

(3) By using a parallel plate track at the tip of the rotating radiator, it is possible to move the center of gravity of the entire rotating radiator toward the coaxial section, which provides stability when the rotating radiator rotates along the rail. The degree increases. (If the center of gravity is toward the tip of the radiator, the coaxial part will be lighter when relative to each other, so vibrations during rotation will cause the coaxial part to move up and down, making it unstable. This means that the coaxial part is not inserted into the waveguide. Since the dimensions change, the coupling between the waveguide and coax changes unstablely, resulting in unstable output.In this case, increasing the rail diameter can improve stability. However, the problem is that the larger the rail diameter, the greater the motor rotational torque.)

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a product showing a conventional example, Fig. 2 is an external perspective view showing the shape of a conventional rotating radiator, Fig. 3 is an external view of a product which is an embodiment of the present invention, and Fig. 4 6 is a sectional view of the same, FIG. 6 is an external perspective view showing the rotary radiator, and FIG. 6 is an external perspective view showing another embodiment of the present invention. 2... Heating chamber, 4 High frequency oscillator, 5... Waveguide, 6... Rotating radiator, 7... Coaxial section, 8...
... Radiation part, 9 ... Waveguide part, 10...
Parallel plate track section. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A heating chamber, a high-frequency oscillator, a waveguide that transmits the radio waves oscillated by the high-frequency oscillator, and a rotating radiator that radiates the radio waves transmitted by the waveguide into the heating chamber, The rotating radiator is a high-frequency heating device composed of a combination K of a simplified waveguide and parallel plate line. (2) The high-frequency heating device according to claim 1, wherein the radiation port is formed by connecting a parallel plate line to the open end of the simplified waveguide.