JPS6337472B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-frequency heating device that dielectrically heats an object to be heated housed in a heating chamber using high-frequency waves.

Conventional configurations and their problems Conventional microwave ovens, such as high-frequency heating devices, use a method of stirring the high-frequency waves supplied into the heating chamber with a stirring blade as a method of uniformly heating the object to be heated within the heating chamber. There is a method in which the object to be heated is placed on a rotating table provided in the heating chamber and rotated, or a method in which a high frequency radiator, that is, a rotating antenna is rotated in the heating chamber. Among these methods, the method in which the rotary antenna is rotated within the heating chamber occupies the smallest portion of the heating chamber, so that the effective volume of the heating chamber can be increased or the main body of the microwave oven can be made more compact. Compared to other methods, the dimensions and shape of the heating chamber are very important in this method of rotating the rotating antenna inside the heating chamber, and if the dimensions of the heating chamber change or the position of the rotation axis of the rotating antenna changes, The shape and dimensions of the rotating antenna also vary widely.

Another drawback was that even if the rotating antenna had the same shape, if its dimensions changed by 1/4 of the wavelength used, not only the high frequency distribution characteristics within the heating chamber but also the output characteristics of the high frequency oscillator would change completely.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and is aimed at reducing the amount of high-frequency radiation radiated vertically from a rotating antenna and the amount of high-frequency radiation radiating horizontally from a horizontal antenna provided on the rotating antenna. It is an object of the present invention to provide a high-frequency heating device that can uniformly heat an object to be heated by improving the distribution characteristics of high-frequency waves within a heating chamber by adjusting the radiation direction and the radiation direction.

Configuration of the Invention In order to achieve the above object, the high frequency heating device of the present invention includes: a heating chamber that accommodates an object to be heated; a high frequency oscillator that supplies high frequency waves into the heating chamber via a waveguide; It is composed of a rotating antenna provided facing substantially vertically into the heating chamber, and a plurality of horizontal antennas provided on the rotating antenna, and the horizontal antenna is provided asymmetrically with respect to the rotating antenna, The amount of high-frequency radiation radiated vertically from a rotating antenna, and the amount and direction of radiation radiated horizontally from a horizontal antenna rotating together with the rotating antenna.
Adjustment can be made by changing the size and shape of the horizontal antenna to improve the distribution characteristics of high frequency waves within the heating chamber, and to dielectrically heat the object to be heated evenly.

Furthermore, since the proportion of the rotating antenna in the heating chamber is small, the effective volume can be increased.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

In FIG. 1, reference numeral 1 denotes a main body of a high-frequency heating device, and a door 3 is provided at the opening of a heating chamber 2 provided in the main body 1 so as to be openable and closable. Reference numeral 4 denotes a heater plate installed on the top of the main body 1. When boiling food etc. using this heater plate 4, the electric power of the plate heater 6 shown in FIG. It is configured so that it can be done. Reference numeral 7 denotes an operation knob B for controlling the output of a heater provided in the heating chamber 2 and a magnetron 8 used as an example of a high-frequency generator.
It is.

In FIG. 2, reference numeral 9 denotes a plate made of a heat-resistant dielectric material provided above the plate heater 6. As shown in FIG. 10 is a heater provided at the top inside the heating chamber 2, and 11 is a heater provided at the bottom of the heating chamber outside the heating chamber 2. This heater 10, 11
This makes it possible to efficiently heat the inside of the heating chamber 2. 12 is a heat insulating material provided around the outer periphery of the heating chamber wall 13. 14 is a tapered waveguide that transmits the high frequency waves generated by the magnetron 8 into the heating chamber 2. Reference numeral 15 denotes a rotating antenna that is provided facing into the heating chamber 2 through the waveguide 14 and the upper wall 16 of the heating chamber, and the rotating antenna 15 includes a plurality of horizontal antennas 17a and 17b as shown in FIG. is provided, and the rotary antenna 15 and horizontal antennas 17a and 17b are rotated by a motor 19 via a belt 18. The horizontal antennas 17a and 17b are provided asymmetrically with respect to the rotating antenna 15, and have a length that is an integer multiple of 1/8 of the oscillation wavelength from the magnetron 8, so that the rotating antenna 15 increases the effective space of the heating chamber 2. Therefore, the wavelength is set to less than 1/4 of the oscillation wavelength.

4 to 6 are horizontal antennas 17a, 17
Rotating antenna 15 by changing the length of b
and the radiation amount and radiation direction of high frequency waves radiated from the horizontal antennas 17a and 17b.
In the figure, the length of the horizontal antennas 17a and 17b is set to 1/4 of the oscillation wavelength, in Fig. 5 the length is 3/8 of the oscillation wavelength, and in Fig. 6 the length is 1/2 of the oscillation wavelength.

FIG. 7 shows another embodiment in which the horizontal antenna 17 is configured in a fan shape, and in order to reduce the weight and rotational torque of the horizontal antenna 17, the oscillation wavelength is 1/10.
A large number of small holes 20 as shown below were provided.

The operation of the above configuration will be explained below.
First, when the object to be heated is housed in the heating chamber 2 and the magnetron 8 is operated by external operation, high frequency waves from the magnetron 8 pass through the waveguide 14 to the motor 19.
The object to be heated is dielectrically heated by being supplied into the heating chamber 2 from the rotary antenna 15 and the horizontal antennas 17a and 17b which are rotationally driven by the heater. The high frequency waves radiated from the rotating antenna 15 and the horizontal antennas 17a, 17b can be adjusted as shown in FIG. 4 by adjusting the lengths of the horizontal antennas 17a, 17b as shown in FIGS. Rotating antenna 1
5, the high frequency waves 21 (electric field) can be radiated from the horizontal antennas 17a, 17b, or the high frequency waves 21 (electric field) can be radiated from the horizontal antennas 17a, 17b depending on the dimensions of the heating chamber 2, as shown in FIG. Since the high frequency waves 21 are canceled, it is possible to radiate high frequency waves in the vertical direction from the rotating antenna 15. However, in order to improve the distribution characteristics of the high frequency waves in the heating chamber 2, the lengths of the horizontal antennas 17a, 17b are adjusted as shown in FIG. The rotating antenna 1
5 and the horizontal antennas 17a and 17b, the distribution characteristics of high frequencies in the heating chamber 2 will be improved.
The object to be heated can be dielectrically heated evenly.

As described above, according to the high-frequency heating device of this embodiment, the lengths of the horizontal antennas 17a and 17b provided on the rotating antenna 15 are adjusted to optimal dimensions depending on the shape and size of the heating chamber 2. Therefore, a balanced amount of high frequency radiation is transmitted from the rotating antenna 15 and the horizontal antennas 17a and 17b to the heating chamber 2.
Since the horizontal antennas 17a and 17b rotate, it is possible to dielectrically heat the object evenly.

Furthermore, since the proportion of the rotating antenna 15 and the horizontal antennas 17a, 17b occupying the heating chamber 2 is small, the volume inside the heating chamber 2 can be effectively utilized, or the main body 1 can be made smaller.

In addition, there are many small holes 20 in the fan-shaped horizontal antenna 17.
In addition to the above-mentioned effect, if the horizontal antenna 17 is made lightweight, the torque of the rotating antenna 15 can be reduced.

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

(1) By installing multiple horizontal antennas asymmetrically on a rotating antenna facing into the heating chamber from the waveguide, high-frequency radiation is radiated vertically from the rotating antenna and horizontally from the horizontal antenna. The amount can be adjusted by the horizontal antenna, and since a plurality of horizontal antennas are rotated, the distribution characteristics of the high frequency waves in the heating chamber are improved, and the object to be heated can be dielectrically heated evenly.

(2) By making the length of the horizontal antenna an odd multiple of 1/8 of the wavelength used, the vertical and horizontal electric fields of the antenna can be excited to the same degree at the same time, so Since two types of heating patterns are combined, the uniformity of heating is extremely high.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a high-frequency heating device according to an embodiment of the present invention, FIG. 2 is a front sectional view of the high-frequency heating device shown in FIG. 1, and FIG. 3 is a view of the rotating antenna shown in FIG. 2. The perspective view, FIG. 4, FIG. 5, and FIG. 6 are schematic diagrams of high frequency waves radiated from the rotating antenna shown in FIG. 2, and FIG. 7 shows another embodiment of the rotating antenna shown in FIG. 2. FIG. 2... Heating chamber, 8... Magnetron (high frequency oscillator), 14... Waveguide, 15... Rotating antenna,
17a, 17b...Horizontal antenna.

Claims (1)

[Scope of Claims] 1. A heating chamber that accommodates an object to be heated, a high-frequency oscillator that supplies high-frequency waves into the heating chamber through a waveguide, and a high-frequency oscillator that is provided facing approximately perpendicularly from the waveguide into the heating chamber. and a plurality of horizontal antennas provided on the rotating antenna, and the horizontal antenna is provided asymmetrically with respect to the rotating antenna, and the length of the horizontal antenna is set so as to correspond to the wavelength used. High frequency heating device with odd number multiple of 1/8. 2. The high frequency heating device according to claim 1, wherein the horizontal antenna is configured in a fan shape.