JP3249240B2 - microwave - Google Patents

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 radio waves from leaking from a microwave oven.

[0002]

2. Description of the Related Art Conventionally, this kind of microwave oven is disclosed in
-43287. The sealing surface is in contact with a flange provided on the peripheral edge of the opening of the heating chamber, a side wall surface extending substantially at right angles from an end of the sealing surface, and a substantially right angle extending from an end of the side wall surface. The bottom surface is integrally formed with the door body, and the bottom surface has a mounting surface that makes planar contact with the bottom surface,
A U-shaped conductor piece formed from an upright surface extending substantially parallel to the side wall surface from an end of the mounting surface, and a projecting surface extending substantially parallel to the bottom surface from an end of the upright surface. Is attached.

A door of a microwave oven in which the above-described U-shaped conductor piece is attached to the bottom surface of a door body will be described with reference to FIGS. 1, 2 and 3.

In FIG. 1, 1 is a microwave oven main body, 2 is a heating chamber for storing a heating object, 3 is a door for opening and closing a front opening of the heating chamber 2, and 4 is provided on a peripheral edge of the front opening of the heating chamber 2. Reference numeral 5 denotes an operation unit for performing a heating operation of the microwave oven.

FIGS. 2 and 3 show the door 3 with the door panel removed. Reference numeral 6 denotes a door body of the microwave oven, 7 denotes a punching plate portion provided substantially in the center of the door body 6 and has a large number of punching holes, 8 denotes the punching via a step 9 bent toward the microwave oven body side. The sealing surface 10 extending substantially in parallel with the plate portion 7 and in the outer peripheral direction of the door body 6 and in planar contact with the flange 4 is formed in a direction opposite to the step 9 and at a substantially right angle from an end of the sealing surface 8. 11 is a side wall surface which is bent and extended
0, a bottom surface extending from the end of the door body 6 in the outer peripheral direction of the door body 6 at a substantially right angle, and an outer wall 12 extending from the end of the bottom surface 11 at a substantially right angle in the same direction as the step portion 9 to extend. It is. The height of the outer side wall 12 is much lower than the height of the side wall surface 10.

The punching plate 7, the sealing surface 8, the step 9, the side wall surface 10, the bottom surface 11, and the outer wall 12 are formed on the outer periphery of the door body 6 and are integrally formed by press working. .

Reference numeral 13 denotes the bottom surface 1 of each of the four sides of the door body 6.
1. A U-shaped conductor piece serving as a periodic structure attached to the mounting surface 1. The mounting surface 14 is in planar contact with the bottom surface 11, and the upright surface 15 extends from an end of the mounting surface 14 in parallel with the side wall surface 10. And a projecting surface 16 that extends from the end of the upright surface 15 in the direction of the side wall surface 10 and extends. Further, the upright surface 15 and the overhanging surface 16 are not continuous along the outer periphery of the door body 6, and the slits 1 are arranged at equal intervals.
7 are provided.

Incidentally, the slit 17 is formed on the upright surface 1 in the above.
5 and the overhanging surface 16, but in this state, the strength of the U-shaped conductor piece 13 is low, and when it hits something at the time of manufacturing, it bends immediately and its dimensions change, causing radio wave leakage. Alternatively, only the overhanging surface 16 may be provided in order to emphasize the strength.

A choke groove is formed by the side wall surface 10 and the bottom surface 11 of the door body 6 and the U-shaped conductor piece 13.

[0010]

In FIG. 2, however, the degree of curvature of the side wall surface 10 at the corner of the door body 1 and the degree of curvature of the outer wall surface 12, that is, the radius of the arc between x and y in the T portion is too small. I can't make it smaller.

[0011] This is because when forming a corner portion by press working, a large tension is applied compared to other portions because the material of the corner portion is formed in a curved line, but tension is applied when the radius of the corner portion is small. The area is reduced and the tension per unit area is increased, causing the material to withstand the tension and crack.

Further, since the overhang dimension B of the overhang surface 16 of the U-shaped conductor piece 13 is all the same, the overhang surface 1 at the corner portion is determined by the distance A between the end of the overhang surface 16 and the side wall surface 10.
The distance A 'between the base 6 and the side wall surface 10 becomes large.

Therefore, the resonance frequency of the choke groove other than the corner portion coincides with the frequency of the radio wave leaking from the microwave oven main body 1 and can be prevented from leaking outside.
In the corner, the distance A 'became larger than the distance A,
The resonance frequency does not coincide with the leaked radio wave in the direction of increasing the resonance frequency, so that the leak of the radio wave cannot be prevented.

The present invention is to solve such a problem.

[0015]

Means for solving the problems of the present invention include a heating chamber provided with an opening having a flange portion around it for storing a heated object, a door for opening and closing the opening of the heating chamber. Comprising a U-shaped conductor piece attached to the door,
The door has a sealing surface facing the flange portion when closed, a side wall surface extending at a right angle from an end of the sealing surface and extending away from the flange portion, and a substantially right angle from an end of the side wall surface. And a bottom surface substantially parallel to the sealing surface, and the U-shaped conductor piece has a mounting surface in contact with the bottom surface and the side wall surface extending from an end of the mounting surface. A parallel upright surface, a projecting surface extending from the end of the standing surface in the direction of the side wall surface, and a slit provided at least at a predetermined interval on the projecting surface, wherein a portion near the corner of the door is provided. The overhang dimension of the overhang surface is larger than the overhang dimension of the other overhang surface, and the corner of the door
The overhang surface near the corner is in front of the corner near the door.
The distance between the end of the overhang surface and the side wall surface is different from that of the other portion.
So that it is not equal to the distance between the end of the overhang surface and the side wall surface
It is a configuration that overhangs each time .

Also, a heating chamber provided with an opening having a flange portion for storing a heated object, and a door for opening and closing the opening of the heating chamber are provided, and the door faces the flange portion when closed. A sealing surface, and a side wall surface extending at a substantially right angle from an end of the sealing surface and extending away from the flange portion,
A bottom surface extending substantially at a right angle from an end of the side wall surface and substantially parallel to the sealing surface; an upright surface extending substantially parallel to the side wall surface from an end of the bottom surface; and an end portion of the upright surface A projecting surface substantially parallel to the bottom surface extending in the direction of the side wall surface, and slits provided at least on the projecting surface at predetermined intervals, and the bottom surface, the upright surface, and the projecting surface have a U-shape. In the formation of a conductor piece, the overhang dimension of the overhang surface near the corner of the door is larger than the overhang dimension of the other overhang surface .
And the overhanging surface near the corner of the door
The end of the overhang surface near the corner of the door and the front
The distance from the side wall surface is different from the end of the overhang surface of the other portion.
The overhang is such that it does not become equal to the distance from the side wall surface .

[0017]

In other words, by making the overhang dimension of the overhang surface of the U-shaped conductor piece near the corner of the door larger than that of the other portions, the side wall surface of the door body and the end surface of the overhang surface can be reduced. To make the resonance frequency other than the corner portion substantially equal to the resonance frequency of the corner portion, thereby preventing leakage of radio waves.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but those denoted by the same reference numerals as those of the above-mentioned prior art have the same functions and will not be described.

In FIG. 4, of the overhanging surfaces 16 of the U-shaped conductor pieces 13, the overhanging surface 18 facing the corner portion T of the door body 6 has a shape substantially along the side wall surface 10 and extends to the side wall surface 10. The protruding dimension B 'is made larger than the other overhanging dimensions B.

The overhang dimension B 'is extended until the distance A' between the end of the overhang surface 18 and the side wall surface 10 is equal to the distance A between the end of the overhang surface 16 and the other portion of the overhang wall surface 10. When it is output, the cross-sectional area of the choke groove increases and the resonance frequency shifts in the opposite direction to the lower direction, does not coincide with the leaked radio wave, and it is impossible to prevent radio wave leakage, so it is made larger than the other overhanging surface 18, It does not increase until the distance A 'becomes equal to the distance A.

It should be noted that the shape of the overhang surface 18 is not limited to the shape shown in FIG. 4, but may be a shape substantially along the degree of curvature of the corner portion T, for example, from FIG. The shape as shown may be sufficient.

FIGS. 6 and 7 show another embodiment of the present invention. Unlike the embodiment of FIG. 4 described above, the U-shaped conductor piece 13 is formed integrally with the door body 6. Since the outer wall 12 is eliminated and the upright surface 15 becomes the outer wall of the door body 6 and is integrally formed, the U-shaped conductor piece 13 is formed.
Is removed.

That is, the bottom surface 11, the upright surface 15, and the overhanging surface 16
Form the U-shaped conductor piece 13.

The other parts are not changed at all, and have the same functions as the above-described embodiment.

[0025]

According to the present invention, radio waves can be prevented from leaking from the corners of the door, and the safety and reliability of the microwave oven can be improved.

[Brief description of the drawings]

FIG. 1 is an external view of a microwave oven according to the present invention.

FIG. 2 is an enlarged view of a corner portion of a conventional door body.

FIG. 3 is a sectional perspective view taken along the line C-C 'in FIG.

FIG. 4 is an enlarged view of a corner portion of the door body of the present invention.

FIG. 5 is a view showing the shape of a projecting surface of a U-shaped conductor piece.

FIG. 6 is an enlarged view of a corner portion of a door body according to another embodiment of the present invention.

7 is a sectional perspective view taken along the line D-D 'in FIG.

[Explanation of symbols]

 2 Heating chamber 3 Door 4 Flange 8 Sealing surface 10 Side wall surface 11 Bottom 13 U-shaped conductor piece 14 Mounting surface 15 Standing upper surface 16, 18 Projection surface 17 Slit

──────────────────────────────────────────────────の Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05B 6/76 F24C 7/02 521

Claims (2)

(57) [Claims] A heating chamber provided with an opening having a flange portion around the heating chamber for storing a heating object, a door for opening and closing the opening of the heating chamber, and a U-shaped conductor piece attached to the door; The door has a sealing surface facing the flange portion when closed, a side wall surface extending at a right angle from the end of the sealing surface and extending away from the flange portion, and a substantially right angle from an end of the side wall surface. And a bottom surface substantially parallel to the sealing surface, and the U-shaped conductor piece has a mounting surface in contact with the bottom surface and the side wall surface extending from an end of the mounting surface. A parallel upright surface, a projecting surface extending from the end of the standing surface in the direction of the side wall surface, and a slit provided at least at a predetermined interval on the projecting surface, wherein a portion near the corner of the door is provided. The overhanging dimension of the overhanging surface is larger than the overhanging dimensions of the other overhanging surfaces. And the cord of the door
The overhang surface near the corner is near the corner of the door.
The distance between the end of the overhang surface and the side wall surface is
The distance between the end of the overhang surface and the side wall surface must be equal.
A microwave oven characterized by being overhanging . 2. A heating chamber provided with an opening having a flange portion for storing a heated object, and a door for opening and closing the opening of the heating chamber, wherein the door faces the flange portion when closed. A sealing surface, a side wall surface extending at a substantially right angle from an end of the sealing surface and extending away from the flange portion, and extending substantially at a right angle from an end of the side wall surface and substantially parallel to the sealing surface. A bottom surface, an upright surface extending substantially parallel to the side wall surface from an end of the bottom surface, and a projecting surface substantially parallel to the bottom surface extending from the end of the upright surface toward the side wall surface; Slits provided on the overhanging surface at predetermined intervals, and wherein the bottom surface, the upright surface, and the overhanging surface form a U-shaped conductor piece, wherein the overhanging surface of the overhanging surface near the corner of the door is provided. dimensions, a result greater than the projecting length of the other of the projecting surface
In both cases, the overhang surface near the corner of the door is
An end of the overhang near the corner of the door and the side wall;
The end of the overhanging surface and the side wall surface at a different distance from the surface
A microwave oven that is extended so as not to be equal to the distance to the microwave oven.