JPH076873A - Microwave oven - Google Patents

Abstract

PURPOSE:To prevent leakage of a radio wave from a corner part of a door. CONSTITUTION:In a microwave oven, among an overhang surface of a U-shaped conductor piece 13 arranged on a bottom surface 11 of a door body 6, an overhang dimension B' in the direction of a side wall surface 10 on an overhang surface 18 of a corner part is made larger than an overhang dimension B of the other overhang surface 16. Thereby, as for a resonance frequency of a choke groove formed of the side wall surface 10, the bottom surface 11 and the U-shaped conductor piece 13, both the corner part and other parts can be made almost equal to each other, so that leakage of a radio wave can be prevented in the same way as other parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave leakage prevention structure for a microwave oven.

[0002]

2. Description of the Related Art Conventionally, a microwave oven of this type has been disclosed in Japanese Patent Laid-Open No.
-43287. This is a sealing surface that comes into planar contact with a flange provided on the periphery of the opening of the heating chamber, a side wall surface that extends substantially at a right angle from the end of the sealing surface, and a substantially right angle that extends from the 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 comes into planar contact with the bottom surface,
A U-shaped conductor piece formed of an upright surface extending from an end of the mounting surface substantially parallel to the side wall surface, and an overhanging surface extending from an end of the upright surface substantially parallel to the bottom surface. Is attached.

A microwave oven door in which the above-mentioned U-shaped conductor piece is attached to the bottom surface of the 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 accommodating a heating object, 3 is a door for opening and closing a front opening of the heating chamber 2, and 4 is a peripheral edge of the front opening of the heating chamber 2. The flange 5 is an operation unit for heating the microwave oven.

The door 3 with the door panel removed is shown in FIGS. 6 is a door body of the microwave oven, 7 is a punching plate portion provided substantially at the center of the door body 6 and having a large number of punching holes, and 8 is the punching through a step portion 9 bent toward the microwave oven body. A sealing surface 10 which extends substantially parallel to the plate portion 7 and extends in the outer peripheral direction of the door body 6 and which comes into planar contact with the flange 4 is provided with an end portion of the sealing surface 8 in a direction opposite to the step 9 and at a substantially right angle. A side wall surface 11 which is bent and extended into
A bottom surface extending from the end portion of 0 toward the outer peripheral direction of the door body 6 at a substantially right angle, and an outer wall 12 extending from the end portion of the bottom surface 11 at a substantially right angle in the same direction as the stepped portion 9. Is. The height of the outer wall 12 is much lower than that of the side wall surface 10.

The punching plate portion 7, the sealing surface 8, the step portion 9, the side wall surface 10, the bottom surface 11 and the outer side 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 on each of the four sides of the door body 6.
1 is a U-shaped conductor piece serving as a periodic structure that is attached to 1, and has a mounting surface 14 that comes into planar contact with the bottom surface 11, and an upright surface 15 that extends from an end of the mounting surface 14 in parallel with the side wall surface 10. And an overhanging surface 16 extending from the end of the upright surface 15 toward the side wall surface 10. 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 evenly spaced.
7 is provided.

Incidentally, the slit 17 is the rising surface 1 in the above description.
5 and the overhanging surface 16, the strength of the U-shaped conductor piece 13 is low in this state, and if it hits anything during manufacturing, it will bend immediately and the dimensions will change, causing radio wave leakage. Alternatively, it may be provided only on the overhanging surface 16 in order to emphasize strength.

The side wall surface 10 and the bottom surface 11 of the door body 6 and the U-shaped conductor piece 13 form a choke groove.

[0010]

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

This is because when the corner portion is formed by press working, the material of the corner portion is formed in a curved shape so that a larger tension is applied as compared with the other portions, but when the radius of the corner portion is small, tension is applied. The area becomes smaller and the tension per unit area becomes larger, which causes the material to withstand the tension and crack.

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

Therefore, the resonance frequency of the choke groove other than the corner portion matches the frequency of the radio wave leaking from the microwave oven main body 1 and can be prevented from leaking to the outside.
At the corner, the distance A'becomes larger than the distance A,
The resonance frequency does not match the leaked radio wave in the high direction, and the leak of the radio wave cannot be prevented.

The present invention solves this problem.

[0015]

Means for solving the problems of the present invention include a heating chamber provided with an opening having a flange portion in the periphery for accommodating a heating object, and 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 substantially at a right angle from an end portion of the sealing surface and extending in a direction away from the flange portion, and a substantially right angle from an end portion of the side wall surface. And a bottom surface that is substantially parallel to the sealing surface, and the U-shaped conductor piece has a mounting surface that contacts the bottom surface and a sidewall surface that extends from an end of the mounting surface. In the vicinity of the corner portion of the door, in a configuration including a parallel upright surface, an overhanging surface extending from the end of the upright surface in the side wall surface direction, and slits provided at least at predetermined intervals on the overhanging surface, The overhanging dimension of the overhanging surface is larger than the overhanging dimensions of the other overhanging surfaces.

Further, there is provided a heating chamber having an opening having a flange portion for accommodating a heated object, and a door for opening and closing the opening of the heating chamber, the door facing the flange portion when closed. A sealing surface, and a side wall surface extending substantially at a right angle from the end of the sealing surface and away from the flange portion,
A bottom surface that extends from the end of the side wall surface at a substantially right angle and that is substantially parallel to the sealing surface, an upright surface that extends from the end of the bottom surface substantially parallel to the side wall surface, and an end of the upright surface. From the overhanging surface extending in the direction of the side wall surface substantially parallel to the bottom surface, and slits provided at least at predetermined intervals on the overhanging surface, and the bottom surface, the upright surface, and the overhanging surface are U-shaped. In the case of forming the conductor piece, the overhanging dimension of the overhanging surface near the corner portion of the door is larger than the overhanging dimension of the other overhanging surface.

[0017]

In other words, by making the overhanging dimension of the U-shaped conductor piece near the corner of the door larger than the overhanging dimension of other portions, the side wall surface of the door body and the end surface of the overhanging surface are The distance between them is narrowed to make the resonance frequencies other than the corners and the resonance frequencies of the corners substantially equal to each other to prevent radio wave leakage.

[0018]

Embodiments of the present invention will be described below. However, the same reference numerals as those of the above-mentioned conventional technique have the same functions, and therefore the description thereof will be omitted.

In FIG. 4, among the projecting surfaces 16 of the U-shaped conductor piece 13, a projecting surface 18 facing the corner portion T of the door body 6 has a shape that is substantially along the side wall surface 10 and projects to the side wall surface 10. The overhanging dimension B ′ is made larger than the other overhanging dimension B.

This overhanging dimension B'is set so that the distance A'between the end of the overhanging surface 18 and the side wall surface 10 becomes equal to the distance A between the end of the overhanging surface 16 of the other portion and the side wall surface 10. When it is made to extend, the cross-sectional area of the choke groove becomes large and the resonance frequency deviates in the opposite direction to the lower direction, which does not match the leaked radio wave and radio wave leakage cannot be prevented, so it is made larger than the other overhang surface 18, The distance A ′ is not increased until it becomes equal to the distance A.

The shape of the above-mentioned overhanging surface 18 is not limited to the shape shown in FIG. 4, and the shape substantially conforms to the degree of bending of the corner portion T, for example, from (a) to (d) of FIG. It may have a shape as shown.

FIGS. 6 and 7 show another embodiment of the present invention, in which the U-shaped conductor piece 13 is integrally formed with the door body 6 as compared with the embodiment of FIG. 4 described above. Since the outer wall 12 is eliminated and the rising surface 15 becomes the outer wall of the door body 6, and is integrally formed, the U-shaped conductor piece 13 is formed.
The mounting surface 14 of is removed.

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

The other parts are completely the same and have the same functions as those of the above-mentioned embodiment.

[0025]

According to the present invention, it is possible to prevent the electric wave from leaking from the corner portion of the door and improve the safety and reliability of the microwave oven.

[Brief description of drawings]

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

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

FIG. 3 is a cross-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 shape diagram 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 cross-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 surface 13 U-shaped conductor piece 14 Mounting surface 15 Elevating surface 16, 18 Overhanging surface 17 Slit

Claims (2)

[Claims] 1. A heating chamber provided with an opening having a flange portion in the periphery for housing 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 substantially at a right angle from an end portion of the sealing surface and extending in a direction away from the flange portion, and a substantially right angle from an end portion of the side wall surface. And a bottom surface that is substantially parallel to the sealing surface, and the U-shaped conductor piece has a mounting surface that contacts the bottom surface and a sidewall surface that extends from an end of the mounting surface. In the vicinity of the corner portion of the door, in a configuration including a parallel upright surface, an overhanging surface extending from the end of the upright surface in the side wall surface direction, and slits provided at least at predetermined intervals on the overhanging surface, The overhanging dimension of the overhanging surface is larger than the overhanging dimensions of other overhanging surfaces. A microwave oven characterized by its ability to work. 2. A heating chamber provided with an opening having a flange for accommodating a heated object, and a door for opening and closing the opening of the heating chamber, the door facing the flange when closed. The sealing surface, a side wall surface extending substantially at a right angle from the end of the sealing surface and extending in a direction away from the flange portion, and extending substantially at a right angle from the end of the side wall surface, and substantially parallel to the sealing surface. A bottom surface, an upright surface extending from an end portion of the bottom surface substantially parallel to the side wall surface, an overhanging surface extending substantially parallel to the bottom surface extending from an end portion of the upright surface, and at least the above A slit formed at a predetermined interval on the overhanging surface, forming a U-shaped conductor piece with the bottom surface, the upright surface, and the overhanging surface, wherein the overhanging surface of the overhanging surface near the corner of the door is extended. The dimensions are larger than the overhanging dimensions of the other overhanging surface. range.