JPS609090A - 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 Industrial Application The present invention relates to improvement of heating efficiency and radio wave heating distribution in a heating chamber of a high frequency heating device.

Conventional structure and its problems Conventionally, there has been a turntable method in which the food table is rotated as a method for uniformizing the distribution of radio waves in the heating chamber of a high-frequency heating device. Since the structure is such that the radio waves are emitted from the food, the distance from the radio wave radiation source to the food is long, so the radio waves are reflected many times on the heating chamber wall before being absorbed by the food, and are attenuated to some extent before being absorbed by the food. This has the drawback of poor heating efficiency.

In order to cover this defect, approximately central part VC of the bottom wall of the heating chamber is
A method has been proposed in which a dipole antenna is installed, which also serves as the rotation axis of the turntable, and radio waves are radiated from the bottom of the turntable. The disadvantage of this case is that the radio waves from the tie ball antenna mainly heat strongly the bottom center of the food (1=1), and the other parts, especially the edges and the center of the L part, are weakly heated. This is because there is no way to guide the radio waves radiated from the dipole antenna with a guide at the end, so most of the radio waves are absorbed by nearby food.

Purpose of the Invention This invention 1d J1 solves the problems of the conventional technology, and by controlling the radio wave radiation from the bottom of the turntable in the radial direction of the turntable, the heating efficiency is high and the radio wave heating distribution performance is improved. DESCRIPTION OF THE INVENTION In order to achieve the object of F-wave, the present invention provides a heating chamber for storing food, a high-frequency oscillator for supplying high-frequency waves to the heating chamber,
The antenna unit has a food mounting table for placing food on it, a rotating shaft for rotating the food mounting table, and a rotating shaft for rotating the food mounting table. A configuration consisting of a vertical component substantially perpendicular to the wall surface of the heating chamber to be coupled and a horizontal component parallel to it, and the center of the vertical component of the antenna is not made to coincide with the center of the rotation axis of the food mounting table described in RIJ. By providing a horizontal component of the antenna on the food placing table and changing its position and dimensions, it is possible to equalize the two-dimensional and three-dimensional radio wave distribution on the food placing table. This has the effect of making it possible.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will now be described with reference to FIG. m1.

1 is a main body, and a heating chamber 2 is located inside. 3 is a door that allows the front opening of the heating chamber to be opened and closed.

The radio waves oscillated by the high frequency oscillator 12 are transmitted through the waveguide 4 and radiated into the heating chamber from the antenna unit 5 provided on the bottom wall of the heating chamber. The antenna unit 5 consists of a vertical component 6 and a horizontal component 7 arranged in line with the bottom wall of the heating chamber, and is arranged around the food mounting table 13 provided approximately at the center of the bottom wall of the heating chamber. It is provided at a point offset from the center of the single shaft 9.

Numeral 8 is a moon plate for 1:1 ratio of the opening in the bottom wall of the heating chamber through which the vertical component 6 of the antenna passes, and also serves to support the antenna unit. The rotating shaft 9 of the food table 13 is rotatably supported by a bearing 10 and directly connected to the shaft of a motor 11.

The dimensions of the horizontal component 7 of the antenna are shown in Figure 3.
The strength of the 1F field is set so that approximately 1-2 waves are excited, as shown by the two-dot chain line.

The center of the rotation axis 9 of the food table 13 is aligned with or near the center line of the horizontal component 7 of the antenna, and is shifted by about λ/8 along the horizontal component 7 of the antenna from the maximum or minimum point of the anti-nato field. The point is set at the specified point.

The operation of the VC arch with the above configuration will be explained below.

Radio waves oscillated by the high frequency oscillator 12 and guided by the waveguide 4 pass through the vertical component 6 of the antenna and are mainly radiated from the horizontal component 7 of the antenna.

Since the rotary food table 13 is installed just F of the antenna, most of the radio waves emitted from the antenna are reflected by the walls of the heating chamber, etc.! J4: y, <, Directly absorbed into food, therefore, loss is small and heating efficiency is good.

In addition, since the center of the rotation axis of the food table 13 is located at a point shifted along the λ/8 antenna from the maximum or minimum point of the electric field distribution of the antenna E, a certain rotation angle of the food table 13 The food that is the true t of the antenna's electric field minimum point (maximum point) will now be at the electric field maximum point (minimum point) when the food table 13 is rotated 180 degrees from that point.
Every time it rotates 80 degrees, it passes alternately between the maximum and minimum points of the electric field, and as a result, each part is averaged
/Easy to obtain uniform heating distribution. Also, if the center of the vertical component 6 of the antenna and the center of the food table 13 match, the electric field at the center of the food table 13 tends to be strong, so the heating in the center is stronger than in other parts. Although this may be excessive, in the case of this embodiment, the center of the food table 13 is shifted from the center of the vertical component 6 of the antenna and is selected to be approximately halfway between the maximum and minimum points of the electric field, so heating of the central portion is also reduced. It can be made almost equal to other parts.

Effect of the invention According to the present invention, the following effects are achieved.

(1) Radio wave radiation Ill: Since the antenna is installed directly next to the food table, most of the emitted radio waves are directly absorbed by the food, resulting in loss of radio waves. , and heating efficiency is good.

(2) Since the center of the food platform is shifted by 1δ from the center of the vertical component of the antenna, it is possible to suppress the 7Jll heat in the center of the food platform and heat it almost equally to the rest of the table. I can do it.

(3) Since the center of the food table is set at a point λ/8 from the maximum or minimum point of the electric field distribution along the horizontal component of the antenna, food placed on L of the food table is 18
Every time it rotates, it passes through the maximum and minimum points of the electric field alternately, so all parts are averaged and can be heated uniformly.

(4) Since the vertical component of the antenna is located at the center of the food table, the total length of the waveguide can be shortened, and therefore it can be manufactured at low cost.

(5) If the center of the vertical component of the antenna coincides with the center of the food table, there is a high electric field coaxially north of the antenna, and if the rotation axis of the dielectric is placed there, the dielectric Since the VC electric field is concentrated in this area, the electric field in this area becomes abnormally high, resulting in a discharge phenomenon called a spark, which may cause damage to the antenna and rotating shaft. In the configuration of the invention, since there is only a spatial gap at the tip of the antenna, it is possible to prevent sparks caused by abnormal electric field concentration as described above.

(6) Since the waveguide does not extend at the corner of the rotating shaft of the food table, the height of the entire product cannot be increased too much by connecting a motor, pulley, etc. to the rotating shaft. Instead, the product can be made compactly.

[Brief explanation of drawings]

Fig. 1 is an external perspective view of a high-frequency heating device according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of the same, and Fig. 3 is an enlarged view of the main part 11u.
This is a diagram. 1... Main body, 2... Heating chamber, 4... Waveguide, 5... Antenna unit, 6...
・Vertical 1 & minute of antenna, 7...Horizontal component of antenna, 9...Times of food mounting table 11V, 11!1
11.12... High frequency oscillator, 13... Food resistor,

Claims (3)

[Claims] (1) A heating chamber for storing food, a high-frequency oscillator that supplies high-frequency waves to the heating chamber, an antenna unit for the high-frequency oscillator, a food mounting table for placing the food, and a food mounting table for the food. The antenna unit in item 11 is
It consists of a vertical component substantially perpendicular to the wall surface of the heating chamber to which the antenna is coupled, and a horizontal component parallel to it, and the center of the vertical component of the antenna is offset from the center of the rotation axis of the food mounting table. A high-frequency heating device with the following configuration. (2) Center of rotation axis of food table? The high-frequency heating device according to claim 1, which is provided at a point shifted from the maximum or minimum electric field point along the horizontal component of the antenna. (3) The high-frequency heating device according to claim 1, wherein the waveguide is not extended in a certain part of the rotating shaft of the food table.