JPS6329957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high frequency heating device for dielectrically heating an object to be heated such as food.

Conventional structure and its problems Conventional microwave ovens, for example, high-frequency heating devices, use stirrer blades to stir the high-frequency waves supplied into the heating chamber to improve the distribution characteristics of the high-frequency waves within the heating chamber. The object to be heated is uniformly dielectrically heated. However, if the dimensions and shape of the heating chamber change, the high-frequency standing wave mode within the heating chamber also changes, and the radio wave stirring effect of the stirrer blades disappears. Therefore, attempts have been made to improve the distribution characteristics of high frequencies by changing the position and direction of the power supply port that supplies high frequencies into the heating chamber, but since the power supply port deviates significantly from the center of the top and bottom walls of the heating chamber,
When a plurality of objects to be heated are heated at the same time, the rate of temperature rise of the objects to be heated is different, resulting in uneven heating.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a high-frequency heating device that has good distribution characteristics of high-frequency waves in the heating chamber and can cook almost uniformly even if the size and shape of the heating chamber changes. The purpose is to provide

Structure of the Invention In order to achieve the above object, the high-frequency heating device of the present invention connects the high-frequency generator and the heating chamber through a plurality of power feeding ports provided in the waveguide, and uses the high-frequency waves supplied into the heating chamber. The fins of the stirrer blades for stirring are configured to rotate avoiding the power supply port,
Even mode standing waves are excited in the heating chamber, and the excitation electric field at the power supply port is not disturbed, so even if the dimensions and shape of the heating chamber change, a strong electric field is generated at the center of the bottom of the heating chamber, and the object to be heated is This has the effect that the whole can be dielectrically heated evenly.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 denotes a main body of a high-frequency heating device, and a heating chamber 3 for accommodating an object to be heated 2 is provided within this main body 1. 4 is a high frequency generator, and the high frequency generated by this high frequency generator 4 is transmitted through a waveguide 5.
The power is then supplied into the heating chamber 3 from a plurality of power feed ports 6 and 7 of different diameters provided in the waveguide 5. 8
is a stirrer blade installed on the upper wall of heating chamber 3,
It has fins 9 on the periphery and stirs the high frequency waves supplied into the heating chamber 3 from the power supply ports 6 and 7. Fins 9 provided on this stirrer blade 8
is configured to avoid the power feed ports 6, 7 and rotate outside the power feed ports 6, 7 so as not to disturb the excitation electric field of the power feed ports 6, 7. 10 is a plate holder on which the object to be heated 2 is placed.

Note that the power feed ports 6 and 7 provided in the waveguide 5 are provided offset from the center of the heating chamber 3 in order to generate an even mode standing wave in the heating chamber 3.

The operation of the above configuration will be explained below.
When the object 2 to be heated is placed in the heating chamber 3 and the high frequency generator 4 is operated by external operation, the high frequency generated by the high frequency generator 4 passes through the waveguide 5 and is transmitted from the feed ports 6 and 7 with different diameters. It is supplied into the heating chamber 3. The high-frequency electric fields 11 supplied from the power supply ports 6 and 7 into the heating chamber 3 are excited in opposite directions. Therefore, even mode standing waves are excited in the heating chamber 3, so even if the dimensions inside the heating chamber 3 change, a strong electric field can be generated at the center of the bottom inside the heating chamber 3.

On the other hand, when the high-frequency generator 4 is in operation, air that has cooled the high-frequency generator 4 is supplied into the heating chamber 3 through an air passage (not shown), thereby allowing the stirrer blades 8 to be rotated by the cooling air. When the stirrer blade 8 rotates, the fins 9 provided on the peripheral edge of the stirrer blade 8 rotate avoiding the power feed ports 6 and 7, so that the fins 9 inside the heating chamber 3 do not disturb the excitation electric field at the power feed ports 6 and 7. The electric field can be stirred.

As described above, according to the high-frequency heating device of this embodiment, by providing the waveguide 5 with a plurality of power feed ports 6 and 7 having different diameters for supplying high frequency waves into the heating chamber 3, the power feed ports 6 and 7 The electric field excitations at are in opposite directions. Therefore, even mode standing waves are excited in the heating chamber 3, so even if the dimensions and shape of the heating chamber 3 change, a strong electric field can be generated at the center of the bottom of the heating chamber 3. Therefore, even a large object 2 to be heated can be dielectrically heated evenly and almost uniformly.

Furthermore, by offsetting the power supply ports 6 and 7 from the center of the heating chamber 3 and making them different in diameter, a high-frequency heating device with excellent high-frequency distribution characteristics within the heating chamber 3 can be manufactured.

Furthermore, the fins 9 of the stirrer blades 8 that stir the high frequency waves supplied into the heating chamber 3 are configured to rotate while avoiding the power feed ports 6 and 7, thereby disturbing the excitation electric field at the power feed ports 6 and 7. Since the strong electric field within the heating chamber 3 is stirred substantially uniformly, the bottom of the large object 2 to be heated can be dielectrically heated evenly.

Note that FIG. 2 shows another embodiment in which a stirrer blade 8 is provided between the power supply port 6 and the power supply port 7, and the same effect as described above can be obtained.

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

(1) By providing a plurality of power feed ports in the waveguide, the electric fields at the power feed ports are excited in opposite directions, making it possible to excite even mode standing waves into the heating chamber. Therefore, even if the dimensions and shape of the heating chamber are changed, it is possible to generate a strong electric field within the heating chamber.

(2) The fins of the stirrer blades are configured to rotate avoiding the feed port provided in the waveguide, without disturbing the excitation electric field at the feed port.
Since the even-mode standing waves generated in the heating chamber are stirred substantially uniformly, the bottom of the object to be heated can be dielectrically heated evenly.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view of a high-frequency heating device according to an embodiment of the present invention, and FIG. 2 is a front cross-sectional view of a high-frequency heating device according to another embodiment of the present invention. 3... Heating chamber, 4... High frequency generator, 5...
Waveguide, 6, 7...power feed port, 8...stirrer blade, 9...fin.

Claims (1)

[Claims] 1 A heating chamber that accommodates an object to be heated, a high frequency generator that supplies high frequency waves into the heating chamber via a waveguide, and a stirrer blade that stirs the high frequency wave that is supplied into the heating chamber, and the stirrer blade The fins provided in the waveguide rotate while avoiding a plurality of power feed ports of different sizes provided in the waveguide, and the power feed ports are smaller on the high frequency generator side.