KR940008014Y1 - Apparatus for shielding electronic wave of electronic range - Google Patents

Abstract

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Description

Microwave shielding device

1 is a perspective view of a microwave oven.

2 is a perspective view showing an example of a conventional radio wave shield structure.

3 is a cross-sectional view showing another example of a conventional radio wave shield structure.

4 is an exploded perspective view of the radio wave shielding device according to the present invention.

5 is a cross-sectional view of the radio wave shielding device according to the present invention.

* Explanation of symbols for main parts of the drawings

10 seal plate 20 slot member

31, 32: cover

The present invention relates to a radio wave shielding device of a microwave oven, and more particularly, to a radio wave shielding device of a microwave oven that has excellent radio wave shielding ability and does not deteriorate its shielding performance even after long use.

A conventional microwave oven is composed of a main body 2 having a cavity, as in the first diagram, and a door 1 for opening and closing the front surface of the cavity of the main body 2.

In such a microwave oven, a radio wave shielding device is provided to prevent leakage of radio waves.

Conventional radio wave shielding devices have been developed in the following order: metal contact type radio absorber type → radio wave shielding frequency type → tooth type and pickling circuit type → choke type → slot choke type slot slot method.

Among these structures, the choke system of FIG. 2 is effective when used to send a radio wave in a mode determined by the waveguide, but has not sufficiently performed when it is used for radio waves having a plurality of modes such as a microwave oven.

Looking at the structure, as shown in FIG. 2, a metal damping groove 4 is formed to attenuate the microwave traveling in the z-direction and metallic to attenuate the microwave traveling in the x and y directions. The intermetallic contact method of contacting the seal plate (3) and the main body (2) of the system is adopted, and finally, the electromagnetic wave that propagates in the x and y directions cannot be prevented by the intermetallic contact. For this purpose, the electromagnetic wave absorber 5 is attached to the end of the door frame to form a triple choke seal method.

However, these conventional radio wave shields do not restrict the progress of the microwaves due to the diffuse reflection of the microwaves, and because of the large number of parts, the structure is complicated and expensive radio absorbers (5) are used. In this case, the radio wave absorber 5 deteriorates when used for a long time, thereby deteriorating the radio wave shielding performance.

In addition, a radio wave shielding device such as U.S. Patent No. 3,767,884 shown in FIG. 3 has a slot 6 formed in the attenuation groove 4, and has a low impedance characteristic around it. The non-conductive material 7 is filled, and the slot 6 formed in the damping groove 4 is composed of a reactance component required for mode transmission.

However, these radio wave shields suppress the leakage to the outside by forming cut-off resonance by transmitting the microwaves traveling in the x and y directions in the mode. In addition to the excellent shielding ability, the filling of the non-conductive material (7) inside the damping groove (4) not only contributes to the increase in cost, but also requires the thickening of the door to install the device, causing another cost increase. It became.

Therefore, the present invention has been devised to solve these problems in the prior art and described in detail according to the embodiment shown in the accompanying drawings.

4 is an exploded perspective view of a radio wave shield according to the present invention, and FIG. 5 is an assembled sectional view of the radio wave shield according to the present invention.

The radio wave shield according to the present invention, as shown in Figs. 4 and 5, the inner bent portion 11 bent forward from the edge, and the front bent extended outward from the inner bent portion 11 A bent portion 12 and an outer bent portion 13 bent backward at the front bent portion 12 are formed to form a damping groove 14 therebetween and bend inwardly at the outer bent portion 13. A seal plate 10 having a slit portion 15, an inner fixing end 21 fixedly attached to the front bent portion 12 at a position spaced apart from the inner bent portion 11 of the seal plate 10; The inner bent portion 22 and the inner bent portion which are bent from the inner fixing end 21 to the rear side to allow the damped groove 14 and the damped groove 14a partitioned between the inner bent portion 11 and the inner bent portion 21. An inclined bend portion 23 extended to be inclined rearward and outwardly at the portion 22, and a rear bend bent outwardly at the inclined bend portion 23; A portion 24 and an outer bent portion 25 which is bent forward at the rear bent portion 24 and have a slot between the inclined bent portion 23 and the rear bent portion 24 and the outer bent portion 25. A cover which is covered by the slot member 20 having the slot 26, the damping groove 14a between the inner bent part 11 and the inner bent part 22 and in contact with the front surface of the main body 40. 31) and a cover 32 which is attached to the rear surface of the slot portion 15, contacts the inner edge portion to the outer bent portion 25, and contacts metal to the front surface of the main body 40.

The slits 15 are formed with a plurality of slits 15a at regular intervals to form a transmission line and a short circuit so that microwaves do not return to the heating chamber. Here, the slits 15a of the slits 15 are arranged at periodic intervals of? / 4.

According to the present invention configured as described above, when the door is closed, the inner cover 31 contacts the front side front 41 of the main body 40, and the inclined bent portion 23 and the rear bent portion of the slot member 20 ( 24 is in contact with the inclined surface 42 of the main body 40 and the rear side front 43, and the triple contact is made in which the outer cover 32 is in contact with the outer front 42 of the main body 40.

Therefore, the microwave traveling in the x and y directions is suppressed by the triple contact seal and the two damping grooves 14 and 14a, and the microwave of the synthesized wave component, that is, (x, y) (x, z ) And the microwaves in the x, y and z directions, which proceed as the shielding ability is lowered due to deterioration due to triple contact, are completely shielded by the slits 15a arranged periodically.

In addition, the slits 15a were introduced with a λ / 4 concept to give λ / 4 periods, where each dimension is due to the TE mode, and a tuning post at the point where the electric field is maximized in the electric field distribution of the following equation. Install the slits (15a) to play the same role.

In the common sense ego, , K ² = W ² εμ, and Hmn is an arbitrary constant.

Since the gap of the actual door is close to " 0 ", the mode is hardly formed in the y direction, so that n = 0 in the TEmn mode.

Therefore, equation (B) Where Ey '= 0 is the maximum electric field, For Ey '= 0 to be Because it should be Should be

As described above, the present invention can effectively shield microwaves traveling in all directions by the complex method of the triple contact method and the slit structure, and can reduce the cost by not using the radio absorber and the non-conductive material. In addition, even if it uses for a long time, the shielding performance will fall.

Claims (1)

The inner bent portion 11 bent forward at the edge, the front bent portion 12 bent outwardly from the inner bent portion 11, and the outer bent portion 13 bent backward at the front bent portion 12. ) To form the damping grooves 14 therebetween, and the slits 15 having the slits 15a formed at intervals of λ / 4 wavelength are bent inward from the outer bent portions 13. The seal plate 10, the inner fixing end 21 and the inner fixing end 21 fixedly attached to the front bent portion 12 at a position spaced apart from the inner bent portion 11 of the seal plate 10. Inwardly bent to extend rearward to form a damped groove 14a partitioned with the damping groove 14 between the inner bent portion 11 and a rear outer portion at the inner bent portion 22. An inclined bend portion 23 extended obliquely to the back, a rear bent portion 24 bent outwardly from the inclined bend portion 23, and the back bent portion ( Slot member 20 having an outer bent portion 25 bent forward at 24 and having a slot 26 between the inclined bent portion 23 and the rear bent portion 24 and the outer bent portion 25. And a cover 31 which is covered by the damping groove 14a between the inner bent portion 11 and the inner bent portion 22 and in contact with the front surface of the body 40 between metals, and the slit portion 15 of the slitting portion 15. It is attached to the rear side and the inner edge portion in contact with the outer bent portion 25 and the front surface of the main body 40 is provided with a cover 32 which is in contact with the metal between the body and the door is the rear bent portion of the slot member ( 24. A radio wave shield of a microwave oven, characterized in that the metal is brought into contact with a triple metal at the covers 31 and 32.