JPS6135675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the radio wave distribution characteristics of a high frequency heating device having a rotating antenna and an electric heater.

Conventional high-frequency heating devices have an electric heater (hereinafter referred to as a heater) and a rotating antenna (hereinafter referred to as an antenna) in the same heating chamber, but the shape of the heater is not balanced on the left, right, or front and back.
Due to this influence, it was difficult to balance the radio wave distribution inside the heating chamber.

For example, in a configuration where the horizontal parts of the heater and the rotating antenna are installed at almost the same height, and the heater is shaped into an arc along the rotation diameter of the antenna, the transition will occur from a section with a heater around the antenna to a section without a heater. At times, the matching state between the antenna and the heating chamber changes significantly, and therefore the excitation state of radio waves from the antenna into the heating chamber changes between this section and other sections, resulting in a disadvantage that a uniform radio wave distribution cannot be obtained.

The present invention solves the above-mentioned conventional drawbacks, and aims to always keep the radio wave radiation of a high-frequency heating device having a rotating antenna and an electric heater in a stable state and to enable more uniform heating.

In order to achieve the above object, the present invention makes the shape of the heater surrounding the antenna circular with no discontinuity along the rotation of the antenna, and keeps the radio wave radiation from the antenna into the oven in a stable state at all times. Therefore, the above-mentioned conventional drawbacks are improved.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, 1 is a main body, and a high frequency oscillator 2 is provided inside. Radio waves oscillated by the high-frequency oscillator 2 propagate within the waveguide 3 and are radiated into the heating chamber by the antenna 4. A driven pulley 7 is fixed to the rotation drive shaft 6 of the antenna 4, and the rotation drive torque of the motor 8 is applied to the drive pulley 9.
and is transmitted to the driven pulley 7 via the belt 10. Reference numeral 11 is a door that allows the front opening of the heating chamber 5 to be opened and closed, and reference numeral 12 is a food mounting table on which the food to be heated is placed. A heater 13 is provided at a portion above the heating chamber 5 at approximately the same height as the horizontal portion of the antenna 4, and the shape of the heater 13 is such that it surrounds the rotational diameter of the antenna 4 in a circular shape as shown in FIG. It's getting old. If the heaters 13 cross or touch each other, the antenna 4 cannot be completely surrounded by the heaters 13 alone because overheating occurs at that part. By connecting with the supporter 14, the antenna 4 can be formed in a concentric circle without any discontinuity.
It has a structure that surrounds it.

If there is no heater 13 like this around the antenna 4, or if there is a heater but its shape is discontinuous as described above, depending on the rotation angle of the antenna 4, the tip of the antenna 4 and the heating chamber wall surface or Since the distance to the heater changes, the operating impedance changes at that point, making the excitation from the horizontal part of the antenna unstable. However, in the case of the present invention, the heater 13
Since it is provided at the same height as the horizontal part of the antenna 4 and in a concentric circle shape with no discontinuity surrounding the antenna 4, there is little change in impedance due to rotation of the antenna 4, and radio wave radiation from the horizontal part of the antenna 4 is minimized. can be obtained stably.

If the radio wave radiation from the horizontal part of the antenna 4 is not stable, the amount of radio wave radiation will be extremely reduced or increased at a certain rotation angle, resulting in uneven heating of the food to be heated in the heating chamber 5. arise.

As described above, according to the present invention, since an existing electric heater and its support are used, there is no need to provide a reflector, and it is possible to provide a high-frequency heating device with a simple and inexpensive structure and good heating distribution performance. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of a high-frequency heating device according to an embodiment of the present invention, and FIG. 2 is a plan view of a main part of the device. 2... High frequency oscillator, 3... Waveguide, 4... Rotating antenna, 5... Heating chamber, 13... Electric heater, 14... Support tool.

Claims (1)

[Claims] 1. A heating chamber that stores food to be heated, a high-frequency oscillator that supplies high-frequency waves into the heating chamber, a waveguide that transmits the high-frequency waves oscillated by the high-frequency oscillator, and a high-frequency power source that connects the waveguide and the heating chamber with high-frequency waves. a rotating antenna coupled to the heating chamber, an electric heater provided in the heating chamber, and a support for supporting the electric heater, wherein the electric heater and the support are at approximately the same height as the horizontal portion of the rotary antenna. The high-frequency heating device is provided at a position of the rotary antenna, and has a circular portion formed approximately concentrically around the rotation axis of the rotary antenna, the portion being larger than the rotational diameter of the rotary antenna and having no discontinuous portions.