JP3931091B2 - High frequency heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating apparatus that heats food using microwaves.
[0002]
[Prior art]
In a conventional high-frequency heating device, as seen in, for example, Japanese Patent Application Laid-Open No. 2000-257873, the rotating body is stopped at a position where the input current or the input power becomes maximum during one rotation of the food mounting rotating body. In addition, there has been proposed a technique in which microwaves are concentratedly irradiated on food on a rotating body to increase heating efficiency.
[0003]
[Problems to be solved by the invention]
In the conventional technique, the food is heated by stopping the rotating body at a position where the input current or the input power becomes maximum during one rotation of the food mounting rotating body. However, when the input current and input power are maximum, it cannot be said that the position of the rotating body is necessarily irradiated with the maximum microwave and heated, and the food is not efficiently heated from the value of the input current and input power. There was a problem. Furthermore, there is a problem that extreme heating unevenness occurs when the rotating body is stopped.
[0004]
[Means for Solving the Problems]
In the present invention in order to solve the above problems, a heating chamber for accommodating food, a magnetron for oscillating a microwave, and a waveguide for guiding the microwaves to the heating chamber to oscillate from the magnetron, a heating chamber a rotating antenna provided, installed in the high-frequency heating device and a drive motor for rotating the rotating antenna, a microwave detecting device for detecting a microwave incident and reflected signals in the waveguide into the waveguide Then, a predetermined rotation angle is calculated based on the microwave incident signal and reflection signal for each rotation angle of the drive motor detected by the microwave detection device, and the rotation antenna is longer than the other rotation angles at this rotation angle. The rotation is stopped .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a main part of a high-frequency heating apparatus, and 1 is a food. Reference numeral 2 denotes a heating chamber for heating the food 1. 3 is a table plate which is provided in the lower part of the heating chamber 2 to lay the space 2a between the bottom of the heating chamber 2 and the food 1 to be heated is placed thereon. A rotating antenna 4 is provided in a space 2 a between the table plate 3 and the bottom surface of the heating chamber 2 so as to be rotatable, and controls the heating of the food 1.
[0006]
Reference numeral 5 denotes a magnetron that oscillates a microwave. A waveguide 6 is provided outside the bottom surface of the heating chamber 2 and guides the microwave generated in the magnetron 5 to the heating chamber 2. Reference numeral 7 denotes a microwave detection device for detecting microwave operation information installed on the long side surface of the waveguide 6. A drive motor 8 is provided outside the waveguide 6 and has a drive shaft 8a that passes through the heating chamber 2 and the opening 2b provided in the waveguide 6. The rotating antenna 4 is fixed to the upper end of the drive shaft 8a. The rotating antenna 4 is rotatable. The drive motor 8 is, for example, a stepping motor capable of controlling the rotation angle. The opening 2b and the drive shaft 8a constitute a coaxial transmission line, and microwaves are sent from the waveguide 6 to the heating chamber 2.
[0007]
Reference numeral 9 denotes a control arithmetic unit which calculates based on the operation information of the microwave signal detected by the microwave detection device 7 and controls the operation of the drive motor 8 based on the information obtained by the calculation.
[0008]
Next, the operation of this embodiment having the above configuration will be described.
When the food 1 is placed on the table plate 3 and heating is started, the magnetron 5 oscillates and reaches the space 2a where the rotating antenna 4 is located from the waveguide 6 through the opening 2b. Further, simultaneously with the start of heating, the drive motor 8 also operates to rotate the rotating antenna 4. The microwave is diffused by the rotating antenna 4 and passes through the table plate 3 to heat the food 1.
[0009]
On the other hand, also in the microwave detection device 7, simultaneously with the start of heating, the microwave incident signal and reflection signal for each rotation angle of the drive motor 8 are captured and transmitted to the control arithmetic device 9, where the reflection coefficient Γ or the voltage standing wave is transmitted. The ratio ρ is calculated, and a plurality of small values based on the minimum value are selected. For example, FIG. 2 shows the relationship between the rotation angle and the reflection coefficient Γ when the rotating antenna 4 makes one rotation. The minimum point A and the small points B and C in FIG. Each position is stored in the control arithmetic unit 9. Then, the drive motor 8 is controlled by the control arithmetic unit 9 so that the rotating antenna 4 stops at, for example, 10 seconds at each of the points A, B, and C, and the rotating antenna 4 is stopped to continue heating the food 1.
[0010]
The operation of stopping the rotating antenna 4 varies depending on the shape, weight, heating time, etc. of the food 1. For example, the stop time at each of the points A, B, and C of the rotating antenna 4 is distributed long in the order of decreasing reflection coefficient Γ or voltage standing wave ratio ρ. Further, the number of times of stopping is also set in advance so as to change depending on the length of the heating time.
[0011]
Then, the heating is finished when a predetermined temperature or time is reached.
[0012]
In this way, the reflection coefficient Γ or the voltage standing wave ratio ρ is obtained from the microwave oscillated from the magnetron 5, the stop position of the rotating antenna 4 is determined from this value, the rotating antenna 4 is stopped, and the food 1 is heated. Thus, even if the amount and shape of the food 1 and the position of the food 1 are changed, the food 1 can be efficiently and evenly heated.
[0013]
【The invention's effect】
As described above , according to the present invention , even if the amount and shape of the food to be heated and the position to be placed are changed , the food can be efficiently and uniformly heated .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a high-frequency heating device of the present invention.
FIG. 2 is a diagram showing a relationship between a rotation angle of a rotating antenna and a reflection coefficient obtained when the rotating antenna makes one rotation.
[Explanation of symbols]
1. Food 2 Heating chamber 3 Table plate 4 Rotating antenna 5 Magnetron 6 Waveguide 7 Microwave detector 8 Drive motor 9 Control arithmetic unit

Claims (1)

A heating chamber for accommodating food, a magnetron down for generating microwaves, a waveguide for guiding the microwave oscillated this magnetron down or found in the heating chamber, a rotating antenna provided in the heating chamber, this in the high frequency heating device and a driving motor for rotating the rotating antenna, installed microwave sensing equipment for detecting the incident signal and the reflected signal of the microwave of the waveguide to the waveguide, wherein calculating a predetermined rotation angle based on the microwave incident signal and the reflected signal for each rotational angle of the drive motor detected by the microwave detection device, the rotational longer than the other of the rotation angle in the rotation angle A high-frequency heating device characterized in that rotation of an antenna is stopped .

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