JP2002043052A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that conventionally there is a risk that air quantity for rotating a diffusion antenna cannot be secured by the reduction of the air quantity of a cooling fan, when the lowering of the power source voltage for driving the cooling fan is generated. SOLUTION: This microwave oven is provided with a cooling fan 18 for blowing the cooling air so as to cool a magnetron 9 for heating food in a heating chamber 2, a waveguide 8 connected to the heating chamber 2 and the magnetron 9, so as to guide the microwave oscillated by the magnetron 9 to the heating chamber 2 and formed with a hole for blowing air from the cooling fan 18 into the waveguide 8, an air guide member 19 for guiding the air form the cooling fan 18 to the waveguide 8, and a diffusion antenna 13 for diffusing the microwaves oscillated by the magnetron 9. The air guide member 19 is provided with a first partitioning plate 192 counterposed to the hole of the waveguide 8, and has an orifice 197 for guiding the dispersing cooling air to the waveguide 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven, and more particularly to a microwave oven capable of efficiently heating food.

[0002]

2. Description of the Related Art Some conventional microwave ovens include a radiation antenna in a waveguide. This radiating antenna was arranged so as to be microwave-coupled to a magnetron antenna projecting from the magnetron.
By providing the radiation antenna, it was possible to improve the efficiency of microwave supply to the heating chamber in the microwave oven.

[0003] In addition, some conventional microwave ovens include an antenna on the heating chamber side in addition to the radiation antenna. This further antenna may be composed of a plurality of metal pieces arranged radially from a portion facing the center of the magnetron antenna, or they may be rotatably provided. Such additional antennas were provided for efficiently and evenly supplying microwaves into the heating chamber.

[0004]

In a conventional microwave oven, simply providing a radiation antenna in a waveguide or an additional antenna on a heating chamber side can sufficiently provide impedance matching between the magnetron and the heating chamber. I couldn't plan. When the impedance matching between the magnetron and the heating chamber is not sufficiently performed, most of the microwaves oscillated by the magnetron are not supplied to the heating chamber and are reflected by the magnetron. Therefore, in a conventional microwave oven, it has been desired to efficiently heat food by supplying more microwaves oscillated by a magnetron to a heating chamber.

[0005] When a rotatable metal piece is provided on the heating chamber side, holes for guiding wind for rotating the metal piece are formed in the heating chamber and the waveguide. In consideration of a case where a wire or the like is accidentally inserted from the outside, it is necessary to reduce the diameter of such a hole.

[0006] However, when the diameter of such a hole is reduced, the metal piece cannot be rotated sufficiently. Therefore, even in such a case, since the microwave supplied from the magnetron cannot be sufficiently stirred, the bias of the microwave supplied into the heating chamber cannot be sufficiently eliminated, and the food can be efficiently heated. Did not.

The present invention is to solve such a problem.

[0008]

According to the present invention, there is provided a microwave oven comprising: a heating chamber for accommodating food; a magnetron for heating the food in the heating chamber; and a cooling air for cooling the magnetron. A cooling fan that blows air
A waveguide connected to the heating chamber and the magnetron, guiding a microwave oscillated by the magnetron to the heating chamber, and forming a hole for sending air from the cooling fan to the inside of the waveguide; A first guiding member that guides wind from the cooling fan to the waveguide, and a diffusion antenna that diffuses microwaves oscillated by the magnetron, wherein the first guiding member faces a hole of the waveguide. This is a configuration having a partition plate and an orifice for guiding cooling air to be diverged to the waveguide.

Further, the orifice is bent at a predetermined curvature about the rotation axis of the cooling fan.

[0010] The air guide member may further include a second partition plate for guiding cooling air diverging from the outer periphery of the air guide member to the magnetron.

Further, the second partition plate is attached so as to form an acute angle with the first partition plate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes an exterior of a microwave oven according to an embodiment of the present invention, reference numeral 2 denotes a heating chamber disposed in the exterior 1, and reference numeral 3 denotes an opening / closing front of the heating chamber 2. door,
4 is provided adjacent to the door 3 and includes a key input unit 5 and a display unit 6.
On the operation panel.

2 and 3, an opening 7 is formed in the right side wall 2a of the heating chamber 2 when viewed from the front. Opening 7
, One end of a waveguide 8 is attached from outside the heating chamber 2, and a magnetron 9 is attached to the other end of the waveguide 8. A radiation antenna 11 electromagnetically coupled to a magnetron antenna 10 of a magnetron 9 is disposed inside the waveguide 8. Thereby, the magnetron 9
Is supplied to the heating chamber 2 through the waveguide 8 and the opening 7.

On the heating chamber 2 side of the opening 7, a protective cover 12 is provided. A plurality of diffusion antennas 13 are rotatably attached to the protection cover 12.

When the diffusion antenna 13 rotates, the microwave radiated from the magnetron is rotated by the heating antenna 2.
Spread inside. In the present embodiment, the diffusion antenna 13 is configured to be rotatable, but is not limited thereto, and may be configured not to rotate.

A plurality of the diffusion antennas 13 are attached on the rotating plate 14 by sticking. The rotating plate 14 is
For example, it is made of a dielectric material such as a mica plate. The rotating shaft 15 is attached to the protective cover 12. The rotating plate 14 is rotatably attached to the protective cover 12 by fitting the rotating shaft 15 into a hole provided at the center thereof. The rotary plate 14 corresponds to an antenna support plate that supports a diffusion antenna.

The magnetron 9 has a magnetron antenna 10. The magnetron antenna 10 projects from the magnetron 9 toward the heating chamber 2. Around the magnetron antenna 10, a fixing plate 16 is provided.
Is arranged. The fixing plate 16 is made of a dielectric material such as a mica plate. The radiation antenna 1 is provided on the fixed plate 16.
1 is attached. The radiation antenna 11 is provided around the magnetron antenna 10.
It is arranged in a state where it is coupled with a microwave. When the shape of the radiation antenna 11 is changed, the magnetron 9
The power supply directivity to the heating chamber 2 is changed. For example,
The shape of the radiation antenna 11 is
In this case, uneven heating in the heating chamber 2 can be suppressed.

The diffusion antenna 13 has a portion 13a substantially parallel to the wall surface of the waveguide 8. A portion 13 a of the diffusion antenna 13 that is parallel to the wall surface of the waveguide 8 extends from inside the waveguide 8 to the heating chamber 2. This allows
Since a microwave propagation line is formed between the diffusion antenna 13 and the wall surface of the waveguide 8, the microwave can be more efficiently supplied to the heating chamber 2 via the diffusion antenna 13.

Reference numeral 17 denotes an outer peripheral portion of the diffusion antenna 13. The outer peripheral portion 17 is a portion of the diffusion antenna 13 farthest from the rotation axis 15. The outer edge of the rotating plate 14 is
The diffusion antenna 13 is located on the inner side with respect to the rotation shaft 15 than the outer peripheral portion 17. Thus, even when the rotating plate 14 is inclined with respect to the main surface of the protective cover 12, the outer edge of the rotating plate 14 is prevented from contacting the protective cover 12.

Next, the rotating plate 14 and the diffusion antenna 13
Will be described in detail. FIG. 4 shows a right side view of a frame portion of the microwave oven according to the present embodiment.

A cooling fan 18 for cooling the magnetron 9 is mounted behind the magnetron 9. Note that a wind guide member 19 is attached to the magnetron 9 at a portion facing the cooling fan 18.

A power cord bush 21 made of resin and having a power cord 20 penetrated therein is mounted on the rear plate 1a of the microwave oven exterior 1.

As shown in FIG. 7, the power cord bush 21 includes a power cord penetrating portion 22, an attaching portion 23 to the rear plate 1a, and a substantially rectangular parallelepiped buffer portion 2 having a predetermined thickness.
And 4. The buffer portion 24 has a plurality of through holes 25 and a cut portion 27 provided at a position between the through holes 25 in the side portion 26 of the buffer portion 24.

With the configuration of the power cord bush 24, when the microwave oven falls down from the rear plate 1a side, the power cord bush 24 first comes into contact with the power cord bush 24. Nearby side 2
Numerals 6 bulge laterally to cushion the impact and to prevent deformation of the rear plate 1a.

The wind guide member 19 guides the wind sent by the cooling fan 18 into the magnetron 9 and the waveguide 8. In addition,
The waveguide 8 is provided with an intake hole and an exhaust hole for the air sent by the cooling fan 18. FIG. 5 shows the side view of FIG. 4 from which the magnetron 9 and the baffle member 19 are omitted.
The structure of the waveguide 8 will be described with reference to FIG.

The waveguide 8 is provided with a folded portion 20 at a peripheral portion thereof, and is attached to the outer wall of the heating chamber 2 by screwing the folded portion 20 or the like. The waveguide 8 has two groups of holes formed on its side surface. The holes in the group closer to the cooling fan 18 are the intake holes 21, and the holes in the group farther from the cooling fan 18 are the exhaust holes 22. By forming these holes, the wind sent from the cooling fan 18
It is guided into the waveguide 8 through the intake hole 21, hits the diffusion antenna 13, rotates the rotating plate 14 to which the diffusion antenna 13 is attached, and is discharged out of the waveguide 8 through the exhaust hole 22. You. That is, in the present embodiment, an antenna rotating unit is configured by the cooling fan 18 that rotates the diffusion antenna 13 by rotating the rotating plate 14.

Referring again to FIG. 4, the air guide member 19 guides the wind sent from the cooling fan 18 to the magnetron 9 and the intake hole 21 of the waveguide 8. The air guide member 19 is configured such that a portion facing the air intake hole 21 can prevent foreign matter from entering from outside. FIG. 6 shows a perspective view of the wind guide member 19.

The air guide member 19 includes a frame 191, a first partition 192, a shielding plate 193, a lower plate 194, and an upper plate 1.
95. Further, the air guide member 19 includes the cooling fan 1.
8, the lower plate 194 and the second end are provided at the left end of the lower plate 194.
And a second orifice 197 bent at a predetermined curvature about the rotation axis of the cooling fan 18 on the back surface of the shielding plate 193. And further comprising:

The frame body 191 has a horizontal surface 191a located at the upper portion, and a side surface 19 connected to the horizontal surface 191a and provided from the upper end to the side end of the second partition plate 196.
1b, and is connected to the magnetron 9 and the portion of the waveguide 8 where no hole is formed. Here, the portion of the waveguide 8 where the hole is not formed means a portion of the waveguide 8 closer to the magnetron 9 than the portion where the intake hole 21 is formed.

The first partition plate 192 is configured to correspond to the connection between the magnetron 9 and the waveguide 8. The provision of the first partition plate 192 forms a surface along the air blowing direction of the cooling fan 18, and the air sent from the cooling fan 18 is supplied to the magnetron 9 and the waveguide 8.
Can be successfully sorted.

The shield plate 193 is 1 cm from the surface of the waveguide 8 on which the intake hole 21 is formed so as to face the intake hole 21.
It is configured to be located at a distance from the terminal. Since the shielding plate 193 is provided, in the microwave oven according to the present embodiment, an elongated one such as a wire is
Even when the wire is inserted into the main body, it is possible to avoid a situation in which the wire enters the waveguide 8 through the intake hole 21. In the present embodiment, the shield plate 193 constitutes a wall surface that is installed in the air guide member so as to face the hole of the waveguide and to have a predetermined gap with the waveguide. .

The lower plate 194 forms the bottom surface of the wind guide member 19, and the upper plate 195 forms the top surface of the portion of the wind guide member 19 connected to the waveguide 8. Orifice 1
Reference numeral 97 is configured to guide the cooling air diverging from the back surface of the shielding plate 193 to the waveguide 8. By providing these, the wind sent by the cooling fan 18 is:
It is more efficiently guided to the magnetron 9 and the waveguide 8. In particular, even if the number of rotations of the cooling fan is reduced due to a decrease in the power supply voltage and the amount of air blows is reduced, more air can be guided to the waveguide 8 and the diffusion antenna 13 can be surely rotated. become able to.

The embodiment disclosed this time is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0034]

According to the present invention, even if the power supply voltage for driving the cooling fan drops, the air volume enough to rotate the diffusion antenna can be secured, and uniform microwave heating in the heating chamber becomes possible. .

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a main part along AA ′ in FIG.

FIG. 3 is an enlarged view of a waveguide portion in FIG.

FIG. 4 is a sectional view taken along line B-B 'in FIG.

FIG. 5 is a view in which a magnetron and a baffle member are omitted in the cross-sectional view of FIG.

FIG. 6 is a perspective view of the air guide member of FIG.

FIG. 7A is a top view of a power cord bush,
(B) is a side view of the power cord.

[Explanation of symbols]

1 heating room, 2 waveguides, 3 magnetrons, 5, 25
Diffusion antenna, 6, 26, 36 radiation antenna, 7
Protective cover, 9 rotating plate, 11 magnetron antenna, 16 notch, 18 cooling fan, 19 wind guide member.

Claims (4)

[Claims] 1. A heating chamber for accommodating food, a magnetron for heating food in the heating chamber, a cooling fan for blowing cooling air for cooling the magnetron, and a heating fan connected to the heating chamber and the magnetron. Guiding the microwave oscillated by the magnetron to the heating chamber, forming a hole for sending air from the cooling fan into the waveguide, and blowing air from the cooling fan to the waveguide. A guide member for guiding the gas; and a diffusion antenna for diffusing the microwaves oscillated by the magnetron. The guide member includes a first partition plate opposed to the hole of the waveguide, and a cooling member for diffusing. A microwave oven having an orifice for guiding wind to the waveguide. 2. The microwave oven according to claim 1, wherein the orifice is bent at a predetermined curvature about a rotation axis of the cooling fan. 3. The electronic device according to claim 1, wherein the air guide member further includes a second partition plate that guides cooling air diverging from an outer periphery of the air guide member to the magnetron. range. 4. The electronic device according to claim 1, wherein the second partition plate is attached at an acute angle to the first partition plate. range.