JPS5837958B2 - High frequency heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a heating device that increases the temperature in a heating chamber using a heat source such as a heater or gas to cook an object to be heated, and a heating device that cooks an object by dielectric heating using high frequency waves. This relates to a so-called integrated type high-frequency heating device that is installed in two heating chambers and operated simultaneously, and its purpose is to improve the heating distribution within the heating chamber.

Hitherto, this type of high-frequency heating device has been commercialized first in Europe and the United States, but its main configuration is, in most cases, to introduce high-frequency waves into the heating chamber from the bottom wall of the heating chamber, as shown in FIG.

FIG. 1 is a side sectional view of a typical conventional high-frequency heating device with a heater, in which a heating chamber 2 is installed in the main body 1, and a door 3 that can be opened and closed is installed at the front opening of the heating chamber 2. .

Heaters 4 and 5 are installed above and below inside the heating chamber 2, and when the heaters are energized, the temperature inside the heating chamber 2 rises and becomes an electric oven.

On the other hand, a recess 6 is provided in the center of the bottom wall of the heating chamber, into which a magnetro 7 as a high frequency oscillator, a stirrer blade 9 rotated by a motor 8, and the like are mounted.

Therefore, when magnetron 7 is energized, its antenna 1
High frequency waves are radiated into the heating chamber from zero, and the stirrer blades 9 are used to improve the high frequency distribution within the heating chamber.

The button 11 is a partition plate made of a heat-resistant dielectric material.

When cooking using the high-frequency heating device as described above, place a metal wire mesh 1 on a shelf (not shown) installed on the side wall of the heating chamber.
It was customary to place a container 14 containing a food 13 on top of the wire mesh 12.

The reason for this is that heater heating raises the temperature in the heating chamber to a maximum temperature of about 250°C, so resins cannot be used.
With ceramic saucers, the heat from the heater below the heating chamber is blocked by the saucer, preventing the bottom temperature of the food from rising and resulting in insufficient heating, forcing the use of metal wire mesh. .

As a result, when heater heating and dielectric heating are performed at the same time, the efficiency of dielectric heating deteriorates because high frequencies are blocked by the wire mesh, and when the position of the wire mesh is changed depending on the type of food being cooked, the high frequency distribution changes greatly and worsens. was there.

The present invention eliminates the above-mentioned drawbacks and will be explained below with reference to FIG.

The difference from FIG. 1 is that the electromagnetic waves generated by the magnetron 7 are guided by a waveguide 15 to a power supply port 16 provided approximately in the center of the upper wall of the heating chamber, and the waveguide 15 and the heating chamber 2 are connected to each other. Electromagnetic waves are radiated into the heating chamber 2 by the metal conductor A17 that is coupled to the electromagnetic waves.

This metal conductor A17 is provided approximately perpendicularly to the soil wall of the heating chamber, and at the tip of this metal conductor A17, a metal conductor B1B that is approximately parallel to the soil wall of the heating chamber is connected to the upper heater 4 and the object to be heated.
It is fixed between 3.

In the button diagram, the metal conductors A17 and A18 are fixed with screws 19, but the same result would be achieved even if they were made from a single metal tube and bent instead of screwed together.

The metal conductor A17 is brazed to a heat-resistant dielectric 20 such as ceramic in the waveguide 15, penetrates the waveguide wall through the dielectric 20, and is connected to the motor 21. B1B is rotating.

A ceramic cover 22 through which a metal conductor A17 passes through the center of the button power supply port 16 is fixed to the button power supply port 16.
At the same time, the hot air in the heating chamber is
I try not to go to magnetron 7th grade.

Since the metal conductor A17 and the metal conductor B18 are rod-shaped, even if they rotate under the upper heater 4, the heat of the upper heater 4 is not blocked, so the characteristics do not deteriorate, and high frequencies are also blocked by the upper heater 4. It is absorbed into the food to be cooked 13 without any damage.

Furthermore, even when the metal conductor B18 rotates, it is not blocked by the upper heater, so the uniformity of the radio waves is also good.

Furthermore, if the rotation axis of the metal conductor A17 is provided at the center of the upper part of the heating chamber, the heating balance will be better when a plurality of foods are placed in symmetrical positions, and the distribution of high frequencies will be even better.

As described above, according to the high-frequency heating device of the present invention, the following effects are produced by arranging the power feeding port approximately at the center of the upper wall of the heating chamber and rotating the antenna as described above.

(1) Since the metal conductor rotates near the object to be heated, the electromagnetic field mode near the object to be cooked changes, resulting in a good high-frequency heating distribution.

(2) Since a rod-shaped metal conductor is used, the amount of heat from the heater that is reflected by the metal conductor is small and does not adversely affect the characteristics of the heater.

(3) Since the heater does not block high frequency waves, high frequency heating efficiency is achieved.

(4) Since a rod-shaped metal conductor is used, it is strong and does not bend even when hit by a plate or an object to be cooked, making it highly reliable.

(5) When power is supplied from the lower wall of the heating chamber, the electromagnetic waves are blocked by the wire mesh 12 on which the food to be cooked is placed, so that the electromagnetic field strength in the space between the rooms where the food to be heated is placed, that is, the space above the wire mesh, is reduced by the wire mesh. It becomes weaker compared to the space below.

As a result, thermal efficiency deteriorates. On the other hand, when power is supplied from the upper wall of the heating chamber as in the present invention, the radio waves are not blocked by the wire mesh, and the food to be cooked is placed in a space with a high electromagnetic field strength, resulting in improved efficiency.

This effect is due to the fact that even if the gap between the wires of the wire mesh is large and electromagnetic waves can pass through this gap, the electromagnetic field strength on the feeding side will inevitably become stronger due to the reflection of the electromagnetic wave by the wire mesh.
cormorant.

(6) In relation to (5) above, when power is supplied from the bottom wall of the heating chamber, the surface current flowing to the surface of the wire mesh increases, and the temperature of the wire mesh becomes extremely hot.If the food to be cooked is placed directly on the wire mesh, only the wire mesh portion will burn. It is easy to get dizzy and become dehydrated.

On the other hand, when power is supplied from the earthen wall of the heating chamber, if the food to be cooked is immediately placed on the wire mesh, the electromagnetic field strength near the wire mesh under the food becomes extremely weak, and the rise in the temperature of the wire mesh will have an adverse effect on the food to be cooked. There isn't.

(7) Since the metal conductor A is located approximately in the center of the soil wall of the heating chamber, the metal conductor A can be used even when heating multiple items at the same time.
There is little difference in the distance between the food and the individual food items, and uniform distribution can be achieved.

1. This effect is the same even when the wire mesh is moved vertically within the heating chamber, so by simply improving the heating distribution for buttons at one height, it can be applied to other heights. When the button is moved to this position, the heating distribution does not change even if the button is pressed, and a good distribution can be obtained.

Further, by using the metal conductor B parallel to the upper wall of the heating chamber, the electromagnetic waves fall uniformly from the upper wall of the heating chamber like a shower, so that high-frequency heating can be made uniform.

(8) When emitting high-frequency waves from the lower wall of the heating chamber, use rubber packing to prevent water from steam generated during heating, salty water from spills, water used during cleaning, etc. from entering the high-frequency oscillator unit. The water must be completely cut off.

Furthermore, when these things are applied, it becomes difficult to clean.

However, when the device is installed on the upper wall of the heating chamber, these drawbacks are eliminated, making it economical and improving workability.

Above, electric heater heating has been described as a heating device for raising the temperature inside the heating chamber, but the same is true even if the button is pressed when raising the temperature inside the heating chamber using gas.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of a conventional high-frequency heating device that uses heater heating, and FIG. 2 is a side cross-sectional view of a high-frequency heating device according to an embodiment of the present invention. 2...Heating chamber, 4,5...1 heater (heating device),
7... Magnetron (high frequency oscillator), 12...
Wire mesh, 13...To be cooked, 15...Waveguide, 16.
...Power supply port, 17...Metal conductor A, 18...Metal conductor B.

Claims (1)

[Scope of Claims] 1. A heating chamber that heats an object to be heated within a main body, a high-frequency oscillation device that generates high-frequency electromagnetic waves, and a waveguide that transmits the electromagnetic waves of the high-frequency oscillation device to the heating chamber through a power supply port.
An electric heater is provided in the vicinity of the power supply port to raise the temperature inside the heating chamber, and a wire mesh is provided on which the object to be heated is placed. The waveguide is electrically coupled with a rod-shaped antenna that passes through the feed port, and this antenna is bent approximately at right angles between the object to be heated and the electric heater, and is rotatably installed in a high-frequency heating device. . 2. The high-frequency heating device according to claim 1, wherein the rotation axis of the antenna is provided at the center of the heating chamber.