JPH08236270A - Microwave range - Google Patents

Abstract

PURPOSE: To control heating unevenness and at the same time perform the collection and distribution of an electric field due to diffused reflection by providing a plurality of projection parts in a heating bottom wall facing against a food placing base in the lower part of a heating chamber to disperse a microwave. CONSTITUTION: A rotary shaft 11 extended from a rotating motor 10 disposed in the lower surface of the bottom wall 2d of a heating chamber 2 is made to pass through the bottom wall 2d to make a turn table engage with the rotary shaft 11. A ring-like seat pushing part 12 is provided in the bottom wall 2d by adopting the rotary shaft as a center to reinforce the bottom wall 2d. Ring-like seat pushing parts 12a, 12b having different diameters are formed in the ring-like seat pushing part 12 concentrical to the center of the rotary shaft 11, and a plurality of projection parts 13 projected in a spherical surface-like form are formed between both of them. Since a microwave supplied to the heating chamber 2 has a different reflecting direction depending upon its hit position on the projection parts 13, the microwave is dispersed by diffused reflection, so that the concentration of an electric field is reduced. A microwave diffusely reflected by the projection parts 13 irradiates foods without being intertwined with a microwave from the upper part of the heating chamber, so that heating unevenness is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of uneven heating of a microwave oven.

[0002]

2. Description of the Related Art Microwave ovens of this kind are known from Jitsuko 48-2.
No. 4206 and Japanese Patent Publication No. 62-44396.

First, in Japanese Utility Model Publication No. 48-24206, a large number of irregularities are provided on a side wall and an upper wall of a heating chamber, and the irregularities diffusely reflect microwaves to stir the microwaves.

Further, in Japanese Patent Publication No. 62-44396, a diameter Φd is provided in a substantially central portion of a bottom wall of a heating chamber located below a placing table on which food is placed, in a direction approaching the placing table. In order to improve the uneven heating, it is possible to eliminate the electric field concentration in the central portion of the heating chamber by forming the protruding portion.

[0005]

In the prior art described above, if a large number of convex and concave portions are provided on the side wall and the upper wall of the heating chamber,
Certainly, microwaves that hit bumps and dips are diffusely reflected, but because the distance between the bumps and dips and the food to be heated is large, the microwaves that have been diffusely reflected from other wall surfaces before hitting the food intersect and the electric field is dense. There was a rough part and a sparse part, which caused uneven heating.

Even if a protrusion is provided on the bottom wall of the heating chamber below the mounting table so that electric field concentration does not occur in the central portion of the heating chamber, it does not diffusely reflect microwaves, but only the protruding distance of the protrusion. The electric field concentration portion is lifted and moved, and this does not eliminate the electric field concentration, but does not eliminate the heating irregularity only at the different positions where the heating irregularity occurs.

Further, in the above-mentioned conventional technique, the wall surface of the heating chamber must be distorted in order to provide the uneven portion and the protruding portion, which may cause deformation of the heating chamber.

The present invention is intended to solve such problems.

[0009]

Means for Solving the Problems The means of the present invention for solving the above-mentioned problems include a heating chamber to which microwaves generated by a magnetron are supplied, and a lower part of the heating chamber.
A placing table for food formed from a material that transmits the microwave, and provided on the bottom wall of the heating chamber facing the placing table,
It is the structure provided with the some convex part which scatters the said microwave.

Further, a reinforcing seat pressing portion is provided on the bottom wall of the heating chamber, and the convex portion is provided in the vicinity of the seat pressing portion.

Further, a rotation motor provided on the outer bottom of the heating chamber for rotating the mounting table, a through hole provided on the bottom wall of the heating chamber, and the mounting table and the rotation motor through the through hole. And a ring-shaped seat pressing portion that is concentric with the through-hole around the through-hole, and the convex portion is provided near the ring-shaped seat pressing portion.

Further, the convex portion is formed as a spherically projecting shape.

[0013]

Action: That is, the microwaves diffusely reflected by the convex portion of the bottom wall of the heating chamber are irradiated to the food nearby before being entangled with the microwaves diffusely reflected from other wall surfaces, so that the electric field concentration is not so large. Food can be heated with and there is little uneven heating.

Further, since the protrusion is provided in the vicinity of the seat pusher at the bottom of the heating chamber, even if the protrusion is provided, it is reinforced by the seat pusher,
It suppresses the deformation of the bottom wall.

Further, since the projection has a spherical shape,
Can reflect microwaves evenly.

[0016]

1 and 2, 1 is a microwave oven main body, 2 is a heating chamber for accommodating a food 3, 4 is a microwave for transmitting glass or ceramic for placing food in the heating chamber 2. A turntable 5 serving as a mounting table made of the material described above is an operation unit having a display unit 6 and a menu selection / start button 7.

The heating chamber 2 is formed by an upper wall 2a, a left side wall 2b, a right side wall 2c, a bottom wall 2d and a rear wall 2e, and a front opening is a door 8 which is pivotally supported at its left end portion and is openably opened laterally. It is blocked. Further, the right side wall 2c is provided with a power supply port 9 for supplying a microwave generated by a magnetron, which will be described later, which is arranged in an electric equipment room at the rear of the operation section 3 into the heating room.

A rotary motor 10 is arranged on the lower surface of the bottom wall 2d of the heating chamber 2, and a rotary shaft 11 extending from the rotary motor 10 is provided through the bottom wall 2d of the heating chamber 2. The turntable 4 is engaged with the rotating shaft 11 to rotate the turntable 4. Therefore, heating cooking is performed while rotating the turntable 4 during cooking to improve heating unevenness. The rotating shaft 1 is provided on the bottom wall 2d of the heating chamber 2.
The bottom wall 2d is reinforced by providing a ring-shaped seat pressing portion 12 with the center of 1 as the center.

As shown in FIG. 3, the ring-shaped seat pusher 12 is formed of two ring-shaped seat pushers 12a, 12b which are concentric with the center of the rotary shaft 11 and have different diameters. And
A plurality of convex portions 13 projecting in a spherical shape are formed between the ring-shaped seat pushers 12a and 12b. Providing the convex portion 13 at this position is because the pushers 12a and 12b push the air to the bottom.
This is because d is reinforced, and it is desired to provide it in the vicinity thereof to prevent the deformation of air toward the bottom. In particular, a microwave oven capable of heating the heater (not described in this embodiment)
In such a high-temperature cooker, the temperature of the heating chamber reaches 200 ° C. or higher, so that the wall of the heating chamber expands, which easily causes thermal deformation. In such a state, the convex portion 13
If you have a configuration that distorts the heating chamber like
This is because the heating chamber is easily deformed.

Explaining the convex portion a little further, in general, as shown in FIG. 5, when a microwave is incident on a plane plate at an incident angle α °, it is reflected at a reflection angle α °. Therefore, in the conventional heating chamber formed of a flat plate, the microwave supplied from the power supply port to the heating chamber is reflected by any wall surface of the heating chamber in a direction to fill the heating chamber. The diffusion did not occur, and a portion where the electric field was concentrated and a portion where the electric field was dispersed were inevitably formed, which caused uneven heating.

However, if there is a spherical convex portion as in the present embodiment of FIG. 6, the direction of reflection differs depending on the position where the convex portion hits, so that the microwaves are diffusely reflected and dispersed, and the electric field concentration. Less. Since the food is placed near the bottom wall of the heating chamber 2, the microwaves diffusely reflected by the convex portions are immediately radiated to the food without being entangled with the microwaves from the upper part of the heating chamber. The unevenness can be improved.

In FIG. 4, reference numeral 14 is a magnetron for supplying microwaves to the heating chamber 2 through a waveguide (not shown), and reference numeral 15 is a door opening / closing detection for detecting whether the door is open or closed. Reference numeral 16 is a buzzer for giving an end notification or abnormality notification, and 17 is a control unit for controlling the microwave oven, which is composed of, for example, a microcomputer.

In the operation of such a structure, first, when the user heats the food 3, the food 3 is placed on the turntable 4 in the heating chamber 2, and then the user closes the door 8. Then, the menu selection and start button 7 is operated to set, for example, warming cooking and heating time, and the start button 7 is operated again to start heating and cooking.

At this time, the control section 17 first confirms that the door open / close detector 15 detects that the door 8 is closed, and drives the magnetron 14 and rotates the rotary motor 10.
To start the rotation. If the door open / close detector 15 detects that the door is open, the driving of the magnetron 14 is prohibited, and the buzzer 16 notifies the user of the abnormality.

During heating, the control unit 17 controls the turntable 4
The microwave is supplied and heated while rotating the food 3 placed on. Simultaneously with this operation, the heating time is measured.

When the set heating time elapses, the control unit 17 stops the operation of the magnetron 14, notifies the end by the buzzer 16, notifies the user of the end, and ends the heating operation.

In the above embodiment, the upper wall 2a of the heating chamber 2 is
The left side wall 2b, the right side wall 2c, and the rear wall 2e are not provided with protrusions similar to the protrusions 13. However, if protrusions are also provided on these wall faces, diffuse reflection of microwaves is further promoted and better results are obtained. To be

Here, taking the warming of a plurality of frozen Shumai as an example, when there is no convex portion on each wall of the heating chamber, the temperature difference between the maximum temperature Shumai and the minimum temperature Shumai The temperature was 26.9 ° C, but when heated in a heating chamber with convex portions on all wall surfaces except the door, the difference between this maximum temperature and the minimum temperature was reduced to 10.4 ° C, and the convexity on the bottom wall of the heating chamber further decreased. When the part is arranged in the position of the present invention,
It has been experimentally obtained that the temperature is 7.9 ° C., and this data also shows that the heating unevenness is improved.

[0029]

According to the present invention, since the convex portion is provided on the bottom wall of the heating chamber, uneven heating is suppressed and the convex portion is provided in the vicinity of the seat pushing portion. Can be prevented from deformation. By forming the convex portion into a spherical shape, microwaves are well diffused, and electric field concentration due to irregular reflection can be dispersed.

[Brief description of drawings]

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

FIG. 2 is an external view of the microwave oven when the turntable is taken out in FIG.

3 is a view of the bottom wall of the heating chamber of FIG. 2 seen from above.

FIG. 4 is a control block diagram of the present invention.

FIG. 5 is a diagram showing reflection of microwaves when hitting a flat surface.

FIG. 6 is a diagram showing reflection of microwaves when hitting a convex portion.

[Explanation of symbols] 2 heating chamber 2d bottom wall 10 rotary motor 11 rotary shaft 12 ring upper seat pressing portion 13 convex portion 14 magnetron 17 control unit

Front page continuation (72) Inventor Katsushi Noda 2-5-5 Keihan Hon-dori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Kayo Sakata 2-5-5 Keihan-hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (4)

[Claims] 1. A heating chamber to which microwaves generated by a magnetron are supplied, a placing table for foods contained in a lower portion of the heating chamber and formed of a material that transmits the microwaves, and an opposing face to the placing table. A microwave oven provided on the bottom wall of the heating chamber, wherein the microwave oven is provided with a plurality of convex portions for scattering the microwave. 2. The microwave oven according to claim 1, wherein a reinforcing seat pressing portion is provided on the bottom wall of the heating chamber, and the convex portion is provided in the vicinity of the seat pressing portion. 3. A rotary motor provided on an outer bottom portion of the heating chamber for rotating the mounting table, a through hole provided on a bottom wall of the heating chamber, and the mounting table and the rotary motor via the through hole. 2. A rotary shaft that connects the ring-shaped seat and a ring-shaped seat pressing portion that is concentric with the through-hole around the through-hole, and the convex portion is provided in the vicinity of the ring-shaped seat pressing portion. Microwave oven described in. 4. The microwave oven according to claim 1, wherein the convex portion has a spherical shape.