JPH06314590A - High frequency leak preventive structure - Google Patents

Abstract

PURPOSE:To adjust the high-frequency attenuation characteristic of a chalk groove to suit the characteristics of high frequencies used. CONSTITUTION:This high-frequency leak preventive structure has a chalk groove 60 provided in a door D and a periodic structure 40 for adjusting the high-frequency attenuating effect of the chalk groove. The periodic structure 40 has first 40a and second 40b comb-shaped periodic members. The first comb-shaped periodic member 40a is roughly L-shaped. The periodic structure 40 is continued at the corner portions of the door D by the L-shaped corner portions 42 of the first comb-shaped periodic member 40a, so leakage of high frequencies can be prevented. The positions of installation of the first and second comb- shaped periodic members 40a, 40b are adjustable within the chalk groove 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing leakage of high frequencies, which can be used for doors of high frequency heating devices.

[0002]

2. Description of the Related Art In recent years, high frequency waves have been effectively used in a wide variety of fields such as heat cooking and dry sterilization. However, this high frequency is harmful when irradiated to the human body,
A device using high frequency is designed so that the high frequency used does not leak to the outside of the device. For example, when cooking food etc. with a high frequency heating device,
Foods and the like are heated and cooked in a heating chamber partitioned by a casing, but a door or a lid for opening and closing the heating chamber is required to put the foods and the like in and out of the heating chamber. Therefore, it is necessary to prevent high frequency from leaking to the outside from between the door and the heating chamber.

Based on the above request, a high frequency leakage prevention structure shown in FIGS. 4 to 6 has been conventionally provided (Japanese Patent Publication No. 60-12755). This high-frequency leakage prevention structure is designed to prevent high-frequency leakage from the inside of the microwave oven by devising the cross-sectional shape of the peripheral portion of the door that opens and closes the heating chamber of the microwave oven. Hereinafter, a brief description will be given with reference to the drawings.

Referring to FIG. 4, FIG. 4 is a partial side sectional view of a microwave oven ER having a vertically opening door 2 in a state in which the door 2 is closed. FIG. 5 is a partially cutaway perspective view of the same portion in FIG. Reference numeral 4 denotes a casing, which has an opening 4a on the front surface thereof and in which a heating chamber 1 for heating foods or the like by high frequency is formed. The opening 4a of the casing 4 is openable and closable by a door 2. By closing the door 2, the heating chamber 1 is partitioned from the outside, and high frequencies are prevented from leaking from the heating chamber 1.

The door 2 has a door body 2a and an inner plate 2b attached to the inside of the door body 2a. When the door 2 is closed, the inner plate 2b is opened by the opening 4a of the casing 4.
The heating chamber 1 is partitioned from the outside by making surface contact with the opening peripheral edge portion 4b. A choke groove 3 is formed in a peripheral portion of the door body 2a on the heating chamber 1 side so as to circulate the peripheral portion, and a comb made of metal is formed in the vicinity of the opening 3a of the choke groove 3. The periodic periodic structure 5 is attached. In addition, 6 is a handle of the door 2.

According to the door 2 having the above-mentioned structure, the high frequency in the heating chamber 1 can be prevented from leaking to the outside by closing the door 2, but the door 2 can be opened and closed via a hinge or the like. Therefore, the inside of the heating chamber 1 cannot be completely sealed. Therefore, it is impossible to completely prevent leakage of high frequencies, and a certain amount of high frequencies leaks. However, this leaked high frequency travels to the outside, but it is prevented from being effectively attenuated by the high frequency attenuation effect of the choke groove 3 and the periodic structure 5 and emitted from the microwave oven ER to the outside. There is.

[0007]

However, there is a problem in mounting the periodic structure 5 at the corner portion 7 of the door 2. FIG. 6 is a view of the corner portion 7 of the door 2 as seen from the heating chamber 1 side. When described with reference to this drawing, the periodic structure 5 is generally attached to each side of the peripheral portion of the door 2. And a corner portion 7 of the door 2 as indicated by reference numeral S.
Are attached by spot welding S at. This is because the mounting position of the periodic structure 5 in the choke groove 3 has a great influence on the high-frequency shielding performance, so that in the manufacturing stage of the microwave oven ER,
This is because the mounting position of the periodic structure 5 in the choke groove 3 needs to be adjustable. That is, by setting the mounting position of the periodic structure 5 to an optimum position that matches the internal impedance in the heating chamber 1, the high frequency attenuation effect of the choke groove 3 is extremely increased and the high frequency leakage is effective. Can be prevented. Therefore, the periodic structure 5 is not continuous in the corner portion 7 of the door 2, and therefore, in such a case, the choke groove 3
If the high frequency attenuation characteristic of the corner portion 7 changes and the gap of the corner portion 7 reaches a predetermined value, the high frequency may leak immediately.

On the other hand, if the periodic structure 5 is continuously formed at the corner portion 7 and integrally formed, the adjustment amount of the mounting position of the periodic structure 5 becomes unique on each side of the peripheral edge of the door 2. turn into. Therefore, it becomes difficult to improve the attenuation effect of the choke groove 3 according to the change of the internal impedance of the heating chamber 1, and it may not be possible to effectively shield the high frequency.

Further, particularly in the vertically opened door 2, since the choke groove 3 must be thinned in the hinge portion of the door 2, the adjustment width becomes narrow and spot welding of the periodic structure 5 becomes difficult. Therefore, the welding is apt to be incomplete, the high frequency is likely to leak from the corner portion 7 of the door 2, and the earth is incomplete. Further, if the number of spots is increased in order to complete the welding, there is a problem that the manufacturing cost increases.

Therefore, an object of the present invention is to provide a high-frequency leakage prevention structure capable of effectively preventing high-frequency leakage in an apparatus utilizing high frequencies.

[0011]

A high frequency leakage prevention structure according to the present invention is a high frequency leakage prevention structure provided on a door for opening and closing an opening of a compartment, wherein the door attenuates high frequencies. And a comb-like periodic structure for adjusting the high frequency attenuation characteristics of the choke groove is installed in the choke groove. Has a first comb-shaped periodic member and a second comb-shaped periodic member, and the first periodic member is continuous in at least one corner portion in the choke groove. It is a thing.

[0012]

According to the high-frequency leakage prevention structure of the present invention, the periodic structure for preventing high-frequency leakage is composed of two members, a first comb-shaped periodic member and a second comb-shaped periodic member. Further, since the first comb-shaped periodic member is continuous at at least one corner portion of the door, the comb-shaped pitch of the periodic structure can be maintained at a predetermined value at the corner portion. Further, by setting the second comb-shaped periodic member at a predetermined position in the choke groove while surrounding the opening through which the high frequency leaks by the first comb-shaped periodic member and the second comb-shaped periodic member, The attenuation characteristic of the choke groove can be adjusted according to the characteristic of the leaked high frequency.

[0013]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. This embodiment shows a preferred embodiment of the high-frequency leakage prevention structure according to the present invention, and is used for the structure of a door that opens and closes the opening of the heating chamber of the microwave oven.

Referring to FIG. 3, this microwave oven ER is
It has a microwave oven main body 10 and a door D attached to the main body 10. The microwave oven main body 10 includes therein a heating chamber 11 as a compartment for heating and cooking the food to be cooked by using a high frequency, and in order to put the food to be taken in and out of the heating chamber 11 on the front surface of the main body 10. 11a is provided. An edge frame portion 11b is formed on the peripheral edge portion of the opening 11a. In addition, 12 is an operation section in which operation switches and the like are arranged, and a desired cooking mode can be selected corresponding to the object to be cooked. The door D is a vertically openable type and is rotatably attached to the microwave oven main body 10 by a hinge or the like (not shown) so that the opening 11a can be opened and closed. When the door D is closed, the inner peripheral edge Di of the door D and the opening 11a are closed.
The edge frame portion 11b of the above is opposed.

FIG. 1 is a schematic side sectional view showing a main part of the microwave oven ER in a state where the door D is closed. The inner peripheral edge portion Di of the door D and the edge frame portion of the opening 11a of the heating chamber 11 are shown in FIG. 11b
It shows a state where and are facing each other. Door D is the door body 2
0, the inside of the door body 20, that is, the door inner plate 30 attached to the heating chamber 11 side of the microwave oven ER, and the periodic structure 4
The door inner plate 30 makes surface contact with the edge frame portion 11b of the microwave oven ER when the door D is closed.

The door body 20 is made of metal and has a hat shape with a brim formed on the periphery. That is, the portion 21 of the door body 20 excluding the peripheral portion 22 has a shape that is raised inside the door D when the door D is closed. Therefore, the peripheral edge portion 22 of the door body 20 is in a state in which the step portion 50 having a substantially L-shaped cross section is formed. The door inner plate 30 is a plate made of metal, and the outer shape thereof is slightly smaller than that of the door body 20. A peripheral edge portion 31 of the door inner plate 30 is slightly raised inward so as to make surface contact with the edge frame portion 11b of the microwave oven ER when the door D is closed.

The periodic structure 40 comprises a first comb-shaped periodic member 40.
a and the second comb-shaped periodic member 40b, the door D
In the closed state, both of the members 40a and 40b surround the peripheral edge portion 22 of the door body 20, and are attached to the peripheral edge portion 22. FIG. 2 is an enlarged perspective view of the first comb-shaped periodic member 40a. First referring to FIG. 2 at the same time
Explaining the comb-shaped periodic member 40a, the first comb-shaped periodic member 40a has a substantially L-shaped shape as a whole, and a large number of claw-shaped claw portions 41 having a U-shaped cross section are formed in the L-shaped shape at a predetermined interval. Are arranged along the claw-shaped portions 4
1 is integrally formed so as to be continuous. In this case, in the first comb-like periodic member 40a, the substantially L-shaped corner portion 42 is arranged at the corner portion of the door body 20, and the claw-shaped opening portion of the claw-shaped portion 41 has the U-shaped opening portion. The main body 20 is installed so as to face the wall surface 51 of the step portion 50 having a substantially L-shaped cross section. Then, the first comb-shaped periodic member 40a is attached to the door body 20 by spot welding the both ends of the substantially L-shape, and in this state, as shown in FIG. L-shaped step 50
And the first comb-shaped periodic member 40a, the choke groove 60 is formed.
Will be formed. In addition, the first comb-shaped periodic member 40
The attachment position of a to the peripheral edge portion 22 of the door body 20 is a position which is set in advance in the design stage and has the highest high frequency attenuation effect due to the high frequency used and the like. The second comb-shaped periodic member 40b has the same shape and attachment as the first comb-shaped periodic member 40a, and therefore the description thereof is omitted. Therefore, the periodic structure 40 is formed by the first comb-shaped periodic member 40a and the second comb-shaped periodic member 40b.
It is in a continuous state at two corners of 0. The comb shape of the first comb-shaped periodic member 40a and the second comb-shaped periodic member 40b, that is, the size of each portion of the claw-shaped portion 41, the distance between the claw-shaped portions 41, and the like are used. The design is appropriately changed according to the high frequency and the like.

According to this embodiment, the periodic structure 40 is formed at two corners of the door D by the first comb-shaped periodic member 40a and the second comb-shaped periodic member 40b which are substantially L-shaped.
Of the periodic structure 40 while keeping the comb-like pitch of the
Can be continuous. Thereby, it is possible to prevent the high frequency from leaking from the corner portion.
Moreover, since the periodic structure 40 is composed of two members, the first comb-shaped periodic member 40a and the second periodic member 40b, the periodic structure 40 surrounding the opening 11a of the heating chamber 11 is formed.
The attachment positions of all sides of the door are not uniquely determined, and these two members 40a and 40b can be set at predetermined positions on the peripheral edge portion 22 of the door body 20. This allows
The door body 20 and the first comb-shaped periodic member 40a or the second comb-shaped periodic member 40b are matched with the characteristics of the high frequency used.
The damping characteristic of the choke groove 60 formed by and can be adjusted, and the damping effect of the choke groove 60 can be improved according to the internal impedance in the heating chamber 11.

Further, since the periodic structure 40 is composed of two members, the first comb-shaped periodic member 40a and the second comb-shaped periodic member 40b, conventionally, each side of the opening 11a of the heating chamber 11 is provided. The number of parts of the mounted periodic structure 40 can be reduced to reduce the cost of parts. Further, since the comb-like periodic members 40a and 40b only need to be spot-welded at both ends of the substantially L-shape, even if the door is a vertically open type, it can be welded at a position where welding is easy. , The earth can be perfect. Also,
The number of spots can be reduced and the assembly cost can be reduced.

The present invention is not limited to the above embodiment, and the periodic structure 40 is composed of two members, a first comb-shaped periodic member 40a and a second comb-shaped periodic member 40b. However, the first comb-shaped periodic member 40a may have a substantially U-shape instead of the substantially L-shape. Also in this case, the first comb-shaped periodic member 40a is in a continuous state at two corners of the door body 20, and the damping characteristic of the choke groove 60 is adjusted by the second comb-shaped periodic member 40b. be able to.

In addition, various design changes can be made without changing the gist of the present invention.

[0022]

According to the present invention, since the periodic structure for improving the high frequency leakage prevention effect is continuous at at least one corner of the door, the high frequency leaks at the corner. Can be prevented.
Moreover, since the periodic structure is composed of the first comb-shaped periodic member and the second periodic member, by attaching these two members at predetermined positions of the door, the choke according to the characteristics of the high frequency leaked from the opening. The damping characteristics of the groove can be adjusted.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing a main part of a microwave oven according to an embodiment of the present invention with a door closed.

FIG. 2 is a perspective view showing a main part of a first comb-shaped periodic member.

FIG. 3 is a perspective view showing the outer appearance of the microwave oven according to the present embodiment.

FIG. 4 is a schematic side sectional view showing a main part of a conventional microwave oven with a door closed.

FIG. 5 is a partial cross-sectional perspective view showing a peripheral portion of a conventional microwave oven door.

FIG. 6 is a plan view of a conventional microwave oven door.

[Explanation of symbols]

 ER microwave oven 11 heating chamber (compartment chamber) 11a opening D door 22 peripheral portion of the door 40 periodic structure 40a first comb-shaped periodic member 40b second comb-shaped periodic member 42 corner (door corner portion) 60 choke groove

Claims (1)

[Claims] 1. A high-frequency leakage prevention structure provided on a door for opening and closing an opening of a compartment, wherein the door has a choke groove for attenuating high-frequency waves around a peripheral portion of the door. A comb-like periodic structure that is formed and adjusts the high frequency attenuation characteristics of the choke groove is installed in the choke groove, and the periodic structure includes a first comb-shaped periodic member and a second comb-shaped periodic member. A high-frequency leakage prevention structure, characterized in that the first periodic member is continuous at at least one corner portion in the choke groove.