JPS5939873B2 - High frequency heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency heating device equipped with a heater inside an open space.

When a heater is installed in an open space equipped with a high-frequency oscillator to cook food, there is a risk of radio waves leaking from the heater.

Therefore, in the past, a choke cavity was provided in the connector part of the heater installed outside the open wall,
A radio wave absorber is installed to attenuate radio wave leakage, but it is structurally complex and difficult to assemble, leading to increased costs. This invention was made based on the above circumstances, and its purpose is to provide a radio wave leak damping pipe into which a heater is inserted into an open wall, and to make the length of this pipe equal to the wavelength (λ), and to It is an object of the present invention to provide a high-frequency heating device that can attenuate radio wave leakage even though it has a simple configuration.

The present invention will be described below based on an embodiment shown in the drawings.

Reference numeral 1 in FIG. 1 is a main body of the high-frequency heating device, and an open 2 is provided within this main body 1. A high frequency oscillator 4 made of a magnetron is attached to the outer surface of the open wall 3 and communicates with the open wall 2 via a waveguide 5.
Heaters 6, 6 are attached to the upper and lower portions of this open 2 by means described later, and are adapted to heat an object 7 to be heated. That is, as shown in FIG. 2, the open wall 3 is provided with a through hole 8, and a radio wave leak damping pipe 10, which is integrated with the board 9, is attached to the outer surface of the open wall corresponding to the through hole 8. It is being The length L of this radio wave leak attenuation pipe 10 is / of the wavelength (λ).
It's getting old. In other words, in the case of a normal microwave oven, the oscillation frequency is 2450MH2 and the wavelength (λ) is approximately 12.2
cm, so it is λ/4 x 30mwL. A mounting portion 12 of the heater 6 is inserted into the radio wave leak attenuating pipe 10 formed in this manner with an insulator 13 interposed therebetween. Further, a metal cover 14 that surrounds the radio wave leak attenuation pipe 10 is protruded from the substrate 9 . An insulator 15 is attached to the opening of the metal cover 14, and radio wave absorbers 16, 16 made of ferrite are attached to the upper and lower portions of the insulator 15, which are interposed between the metal cover 14 and the insulator 15. Furthermore, there is a mounting hole 1 in the center of the insulator 15.
This mounting hole 17 is provided with a connector 18 into which the terminal portion 6a of the heater 6 is inserted. Furthermore, the tip surface 10 of the radio wave leak damping pipe 10
The gap g between a and the insulator 15 is set to 5 mm or more.

With this configuration, radio wave leakage can be further attenuated. That is, as shown in Table 1, when we conducted a radio wave leak test by changing the gap g as appropriate, we found that the gap g was 5m77! It was found that by setting the above value, the attenuation effect is high and the amount of radio wave leakage can be significantly reduced. Therefore, the heated object 7 stored in the oven 2
Radio wave leakage when cooking by the high frequency oscillator 4 is attenuated by the radio wave leak attenuation pipe 10, and further by the radio wave absorber 16 provided outside the connectors 18, 18.
It is attenuated by... According to the inventor's experiments,
As shown in FIG. 2, a radio wave leak attenuation pipe 10 protruding outward is provided on the oven wall 3, and a radio wave leak test was conducted by changing the length of this pipe 10 as shown in Table 2. ) was found to have the highest damping effect. Note that the experimental data shown in Table 2 was obtained by conducting a radio wave leak test by changing only the length of the radio wave leak attenuation pipe 10, and without the metal cover 14, insulator 15, radio wave absorber 16, and connector 18. It was tested with.

As explained above, this invention provides a radio wave leak damping pipe into which a heater is inserted into the oven wall, the length of this pipe is (λ) x, and there is a gap between the tip end surface of the pipe and the insulator. Since the gap is provided, it is possible to significantly attenuate radio wave leakage, and the structure is simple, and the assembly work efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is an overall longitudinal sectional side view showing an embodiment of the present invention;
FIG. 2 is a longitudinal sectional side view with the main parts enlarged. 2...Oven, 3...Oven wall,
4... High frequency oscillator, 6... Heater,
10...Radio wave leak attenuation pipe.

Claims (1)

[Claims] 1 In an oven equipped with a high-frequency oscillator and a heater for heating an object to be heated, a metal cover is provided protruding from the outside of the oven wall, and the terminal part of the heater is inserted into the opening at the tip of the metal cover. The connector is surrounded by an insulator, and a radio wave leak attenuation pipe into which the heater is inserted is provided inside the metal cover, and the length of this pipe is 1/4 of the wavelength, and A high-frequency heating device characterized in that a gap is provided between the insulator and the insulator.