JPS6149396A - Cooking device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cooker equipped with a microwave oscillation device, such as an oven range or a microwave oven. The present invention relates to a cooking device configured to stir microwaves using a stirrer.

[Prior art]

Cooking appliances equipped with microwave oscillators, such as microwave ovens and microwave ovens, use microwaves so that the food to be cooked is evenly heated, in other words, the microwaves are evenly radiated to the food to be cooked. A stirrer is used to stir the waves. The rotation of this stirrer does not require any other dedicated power, if the cooling air of the magnetron, which is a microwave oscillation device, is guided through the scoop formed in the shape of a calm army, and the rotation is caused by the temperature and pressure of the magnetron. This is generally adopted because it is inexpensive and has a simple configuration.

However, it is not necessarily the case that the stirrer described above is sufficiently effective for all foods to be cooked, and for this reason, for example, Japanese Utility Model Application Publication No. 55-160095 has been proposed. This proposal proposes a cooker equipped with a radio wave reflecting plate formed to have a size of two or more microwave wavelengths surrounding the scoop, and the reflecting plate allows microwaves from a microwave oscillator to be emitted from the microwave. The microwave is stirred by the stirrer to Iff E2, and the microwave stirred by the stirrer is reflected back to the stirrer so that the microwave is reflected diffusely, thereby achieving uniform heating of the food to be cooked.

[Problem that the invention seeks to solve]

However, with the above-mentioned configuration, since the radio wave repelling plate is metallic, there are problems such as sparks occurring between it and the stirrer when there is no load, (i.e., when there is no food to be cooked). However, the reality is that it has not been put into practical use.

[Means for solving problems]

The present invention has been made in view of the above-mentioned circumstances, and aims to provide a cooking appliance that can eliminate uneven heating by combining a stirrer and a reflector, which have not been put to practical use in the past. .

The present invention is characterized in that a reflector plate made of a material having a high dielectric constant and a low dielectric loss tangent value, such as ceramic, is arranged around the stirrer.

First, the basic principle of the present invention will be briefly explained below.

As mentioned above, it has been thought to use metal as the microwave repellent plate, but metal has the drawback of generating sparks. By the way, metal has a relative dielectric constant εS
Since it is considered to be the limit state of −■, a substance with a relative dielectric constant εS larger than a certain level can be considered to have properties close to metal, that is, to have an action as a reflecting plate. However, it is said that materials with a high oxidation ratio have a high absorption rate (dielectric loss) of microwaves, especially microwaves around 2450 MHz, which are used in general cooking appliances.
Dielectric loss is proportional to the product of the relative permittivity εS of the object and the dielectric loss tangent (loss coefficient) tanδ, so even if the relative permittivity εS of a person is a person, if the dielectric loss tangent tanδ is sufficiently small, the dielectric loss will be small. Therefore, almost no microwave absorption occurs.

For the reasons mentioned above, if a material with a high dielectric constant and a low dielectric loss tangent value is used as a reflector to be placed around the stirrer, sparks can be prevented during no-load conditions, and dielectric loss of microwaves can be suppressed. For this reason, as a reflector, for example, a material with a relative dielectric constant εS made of barium titanate as a main component is used.
- It was found that a ceramic slope of about 100 is suitable.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a schematic vertical sectional view showing the structure of a cooking appliance according to the present invention.

In the figure, 1 is a cooking chamber, and a waveguide 3 is provided at the upper side of the cooking chamber. The waveguide 3 is connected to the cooking chamber 1 through an opening 31 at its lower side, and is provided with a microwave oscillator 21-ron 2 at the other end. Further, the part near the top of the cooking chamber 1 is partitioned by a protective plate 45, and a waveguide 3 is placed above the protective plate 4I.
A stirrer 4 for stirring the microwaves guided from the microwave to the cooking chamber 1, and a reflector 5.5 arranged to surround the stirrer 4.
...is provided. On the other hand, a bottom plate 6 is placed at the bottom of the cooking chamber 1, and food to be cooked 7 is placed on this bottom plate 6.
゜7... is placed.

Figure 2 shows the stirrer 4 and the fouling plate 5.5 on the upper surface of the protection plate 45.
It is a schematic diagram showing the layout FQ of...

The stirrer 4 is formed in the shape of a windmill with a plurality of blades, and is mounted approximately in the center of the top surface of the cooking chamber 1 so that it can rotate freely with its rotating shaft 40 pointing vertically downward. The waveguide 3 and the cooking chamber 1 pass through the waveguide 3 as shown by the symbol.
The stirrer 4 is rotated by cooling air from the magnetron 2, which is blown toward the stirrer 4 from an opening 31 connecting the stirrer 4.

The protection plate 45 is horizontally fixed near the top of the cooking chamber 1, and is originally intended to protect the stirrer 4, waveguide 3, etc. from contamination by the food to be cooked. A low dielectric constant material such as polypropylene is used, which can transmit water toward the bottom of the cooking chamber 1. On the upper surface of this protection plate 45, that is, the surface facing the stirrer 4, there are a plurality of reflecting plates 5, 5 (He1iI in the embodiment shown in FIG. 2).
... is installed.

These four reflecting plates 5, 5... are made of a material having a high dielectric constant and a low dielectric loss tangent, such as ceramics whose main component is 1 cum titanate, and the angle formed by the two surfaces is has a channel-like shape with an obtuse angle. When the protective plate 45 is installed at a predetermined position close to the top surface of the cooking chamber 1, these reflecting plates 5.5... The central portions of each are located at, and are spaced apart by an appropriate length so as to extend in the tangential direction of the circumference.
Further, each reflecting plate 5 is fixed with its bent portion located on the inner circumferential side so that the surface facing the starter 4 reflects the microwaves from the starter 4 downward.

Note that the angle of each reflecting plate 5 with respect to the radial direction of the starter 4 is not limited to <90° as in this embodiment, and the angle of the magnetron cooling air flowing in from the opening 31 between the waveguide 3 and the top surface of the cooking chamber 1 is The angle may be set at an appropriate angle so that the starter 4 can be rotated efficiently.

In the device of the present invention configured as described above, the magnetron 2
The microwaves oscillated by the microwaves are guided into the cooking chamber 1 from the top opening 31 of the cooking chamber 1 through the waveguide 3, and a part of them passes through the protective plate 45 and directly hits the food to be cooked 7, 7. ..., and the other part is stirred by Starte 4,
A part of the microwaves transmitted through the protective plate 45 and radiated to the food to be cooked 7, 7... and stirred by the starter 4 travels in the direction of the reflecting plates 5, 5..., and a part of the microwaves are directed downward. The other part is reflected to the start 4 and passes through the protection plate 45.
or other reflecting plates 5.5...

In this way, the stirring of the microwave by the starter 4 and the reflection between the starter 4 and each reflecting plate 5 are repeated, and the microwaves reflected by the stirring 1 are sufficiently applied to the food to be cooked in the cooking chamber 1. Since it is radiated, the food to be cooked is heated evenly.

In addition, as mentioned above, a ceramic plate with a high dielectric constant and a low dielectric loss tangent value is used for the reflector plate 5 for reflecting microwaves, so the microwaves are not absorbed and are non-metallic. From, no load, that is, the food to be cooked 7.7...
Even if the magnetron 2 is driven when the * is not housed in the cooking chamber 1, there is no possibility that sparks will be generated.

[Su J Ka]

As detailed above, in the cooker according to the present invention, a plurality of reflecting plates made of a material with a high dielectric constant and a low dielectric loss tangent value, such as a ceramic plate, are arranged around the starter for stirring microwaves. As a result, the microwaves are sufficiently agitated and the food to be cooked is evenly heated, and there is no sparking when no load is applied.

Furthermore, when a reflector is placed around the starter, if it is used to create a calm path for the magnetron cooling air that rotates the starter, the starter can be rotated efficiently, and the microwave agitation will be more effective. It will be done.

In the above embodiment, the reflector is made of a ceramic plate, but other materials may be used as long as they have a high dielectric constant and a low dielectric loss tangent, and the number of reflectors is limited to four. Not sure (
,s Of course.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic vertical sectional view showing the structure of the cooking device according to the present invention.
Figure 2 shows the arrangement of the starter and reflector! FIG. 2... Magnetron 4... Starte 5...
・Reflector plate 45...Protective plate patent Applicant: Sanyo Electric Co., Ltd. Representative Patent attorney: Noboru Kono Figure 1 Figure 2

Claims (1)

[Claims] 1. A cooking appliance equipped with a microwave oscillation device and a stirrer for stirring the microwaves generated by the device, including a material having a high dielectric constant and a low dielectric loss tangent around the stirrer. A cooking utensil characterized by having a reflective plate made of. 2. The cooking appliance according to claim 1, wherein the reflector plate constitutes an air path for cooling air of a microwave oscillation device for rotating the stirrer.