JPH0729677A - High frequency heating device - Google Patents

Abstract

PURPOSE:To provide a high frequency heating device in which flat and vertical heatings are uniformed to a degree such that a frozen food can be thawed. CONSTITUTION:In a system providing a turn table 2 and a stirrer 9 provided on a heating chamber side surface, the stirrer 9 has a plurality of radial grooves 10, the radial grooves 10 have large and small stirrer reflecting plates 15, and the upper stirrer reflecting plate 15 is set larger than the lower reflecting plate when the radial grooves 10 are turned on magnetron side. Thus, uniform heating can be performed at thawing of frozen food and in a tall load such as a milk or sake bottle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating device,
In particular, it relates to uniform heating of foods such as frozen sashimi and frozen meat.

[0002]

2. Description of the Related Art Conventionally, many methods for uniformly heating an object to be heated in a heating chamber have been proposed, such as a stirrer method for stirring high-frequency electromagnetic waves, a turntable method for rotating an object to be heated, and radiation of electromagnetic waves. Many methods have been proposed for rotating the antenna. There is also a system that combines both of them and has both a stirrer system and a turntable system.

A typical example of this is Japanese Patent Publication No. 60-25875.
As shown in (1), a turntable is provided on the bottom of the heating chamber, and a stirrer is arranged at the rear of the heating chamber to uniformly heat the object to be heated in the heating chamber.

[0004]

However, in the above structure, the stirrer has a small stirring effect because the power supply port for the electromagnetic wave heating chamber is located above the heating chamber. There is a drawback that uniformity occurs and the temperature rises quickly especially at the corners.

Also, many methods have been proposed in which an antenna for radiating electromagnetic waves and a stirrer are arranged on the top and a turntable is arranged on the bottom. In this method, the antenna and the stirrer are close to each other, so the stirring effect of the stirrer is sufficient, but it is difficult to reach the central part of the turntable because there is an electromagnetic wave supply part in the upper part, and it is difficult to reach the central part of the turntable. It was difficult to balance with the outer peripheral portion, and the outer peripheral portion inevitably had more heating, and as a result, uniform heating could not be achieved. If there is an electromagnetic wave supply part in the upper part, the electromagnetic wave from the upper part once reflects on the side wall of the heating chamber and reaches the surface of the turntable, so the size of the heating chamber and the position of the upper supplying part may be slightly different. There was a drawback that the degree of heating of the turntable surface would change greatly if it changed. In addition, when milk or the like is put in a cup and warmed, the upper part is inevitably heated strongly.

[0006]

In order to achieve the above object, the present invention has the following constitution.

A heating chamber for heating an object to be heated in the main body,
A high-frequency oscillator that generates high-frequency electromagnetic waves in the heating chamber,
A waveguide that guides the high-frequency electromagnetic waves of the high-frequency oscillator to the heating chamber, a turntable that rotates the object to be heated, and a stirrer that stirs the high-frequency electromagnetic waves in the heating chamber, and the waveguide is The stirrer is housed, the stirrer rotates on a horizontal rotation axis, the power feed port of the waveguide is disposed on the side surface of the heating chamber, and the stirrer is provided with a substantially V-shaped radiation groove. When the radiation groove faces the high-frequency oscillator in the tube, stirrer reflectors are provided above and below the radiation groove, and the height of the upper stirrer reflector is higher than that of the lower reflector. A table on which the turntable is placed is provided below the turntable, and the table is made of metal and has a plurality of radio wave passage openings other than the center of rotation, and the radio wave passage opening is symmetrical with respect to the table. .

[0008]

[Function] By providing a turntable at the bottom of the heating chamber, the difference in heating between the central portion and the outer peripheral portion becomes a problem for the uniformity of load, and the electromagnetic wave is heated by arranging the power supply port for electromagnetic waves on the side surface of the heating chamber. Irradiate the load directly from the side of the room. Therefore, the heated portion on the turntable becomes like the hatched portion in FIG. 1, and the turntable rotates to uniformly heat the portion. Further, since the load is directly radiated from the power supply port of the electromagnetic wave without being reflected on the wall of the heating chamber, even if the dimension of the heating chamber is slightly distorted, the heating uniformity is not affected.

Furthermore, since the stirrer is arranged near the electromagnetic wave feeding port, the effect of the stirrer is great. Further, the stirrer is provided with a radiation groove, and when the radiation groove faces the high frequency oscillator side of the waveguide, it is provided above and below the radiation groove. Because of the stirrer reflector, high-frequency electromagnetic waves that have passed through the radiating groove are directed diagonally downward and are irradiated into the heating chamber, so the bottom part tends to be slightly stronger when warming milk or sake cans, and the top and bottom parts The temperature difference is extremely small. Of course, even for flat loads, almost perfect uniform heating performance can be obtained by stirring the turntable and stirrer. Therefore, the thawing of fish meat can be heated almost uniformly.

Further, the high frequency electromagnetic wave radiated downward by the stirrer is reflected on the bottom surface of the heating chamber, passes through a plurality of radio wave passages symmetrically arranged on the table provided under the table, and can be heated from the lower portion of the food. It is like this.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a household microwave oven will be described below with reference to the drawings.

FIG. 1 is a horizontal sectional view of an embodiment of the present invention. A heating chamber 1 is provided inside the main body, and a turntable 2 is placed at the bottom of the heating chamber 1 to rotate an object to be heated (not shown). A power supply port 4 having an opening cover 3 made of a low-loss dielectric material such as glass is provided on the rear surface, which is the side surface of the heating chamber. The opposing cover 3 is fixed by a packing 5 made of a low loss dielectric such as silicon rubber.

On the other hand, a high frequency electromagnetic wave from a magnetron 6 which is a high frequency oscillator for generating a high frequency electromagnetic wave passes through a waveguide 7 and is agitated by a stirrer 9 rotating faster than the turntable speed by a stirrer motor 8 to be supplied to a power supply port 4. Thus, the heating chamber 1 is irradiated. The stirrer 9 has a stirrer reflector A15 and a stirrer reflector B18, and is provided with a power supply port 4
It controls the way electromagnetic waves are emitted from.

Further, since the output shaft 12 of the stirrer motor 8 is made of a low-loss dielectric material such as ethylene fluoride, the amount of radio waves leaking from the output shaft 12 is small. Further, a complicated structure such as a choke groove for reducing electric wave leakage is unnecessary. The grid-shaped hatching portion 13 of the turntable 2 is a diagram showing a heating portion from the power supply port 4, and is a diagram showing that the turntable 2 is heated uniformly by rotating. Since the rotation axis of the stirrer is in the same plane as the rotation axis of the turntable, the uniformity is further improved.

Numeral 13 is a door for putting in and out an object to be heated, 1
Reference numeral 4 is a control panel. FIG. 2 is a central sectional view of FIG.

In FIG. 2, the turntable 2 is made of a low-loss dielectric such as pottery, and is capable of holding an object to be heated (not shown). Turntable 2
A turntable motor 16 for rotating the turntable is arranged at the bottom of the turntable motor 1
The rotary shaft 6 is connected by a table 17 for rotating the turntable 2.

The waveguide 7 is wide at the stirrer 9, and the stirrer 9 is accommodated therein. An opening cover is attached to the power supply port 4, but the description will be given with the opening cover removed for the sake of explanation.

The high-frequency electromagnetic wave from the magnetron 6 which is a high-frequency oscillator passes through the waveguide 7, is stirred by the stirrer 9 and is irradiated from the power supply port 4 to the heating chamber. The heating chamber is irradiated through the V-shaped radiation groove 10 as shown by the arrow. The high-frequency electromagnetic wave was provided in the radiation groove 10 when the V-shaped radiation groove 10 faced the magnetron side of the waveguide. The stirrer reflector B15 and the stirrer reflector AB1 in which the stirrer is bent at an obtuse angle
Since the stirrer reflector A15 is higher at the heights of 5 and 18, the stirrer reflector A15 is bent slightly obliquely downward as shown by an arrow and is irradiated into the heating chamber due to reflection. Therefore, in the hatched portion 13 shown in FIG. 1, there is a tendency that the bottom portion is heated strongly and becomes weaker toward the upper portion. Further, since the stirrer is rotating, the high frequency electromagnetic wave emitted from the emission groove 10 is emitted downward like a sprinkler.

Further, since the turntable 2 is connected by the table 16 and is rotated by the turntable motor provided in the lower portion, the object to be heated on the turntable 2 is heated almost perfectly and the bottom is slightly strong. As it is heated, even for tall objects such as milk and sake cans,
Since the bottom is a little strong, there is almost no difference in temperature between milk and liquor can. In addition, in the case of a sake can in which the upper part is slightly constricted, the thin upper part tends to be strongly heated, but the temperature difference between the upper part and the lower part in this case is small.

FIG. 3 is a view of the table 17 of FIG. 2 viewed from above. The table 17 is provided with a plurality of symmetrical radio wave passage openings 18 other than the center of rotation, and high-frequency electromagnetic waves emitted downward from the power feed opening 4 are reflected at the bottom of the heating chamber 1 and are substantially evenly arranged on the turntable 2 from the radio wave passage opening. Since the irradiation is applied to the bottom of the object to be heated, the tendency that the bottom of the object to be heated becomes weak is eliminated.

That is, the object to be heated is uniformly heated up and down, and the irradiation of high-frequency electromagnetic waves from the side surface of the turntable and the heating chamber eliminates the heating difference between the center and the periphery of the turntable.

[0022]

According to the present invention, the turntable and the stirrer are arranged on the side of the heating chamber and the opening of the waveguide is provided in the vicinity of the stirrer. The stirrer has a plurality of V-shaped radiation grooves. Is directed toward the high-frequency oscillator in the waveguide, a high-strength stirrer reflector A for reflecting high-frequency electromagnetic waves is provided on the upper side of the radiating groove to irradiate the high-frequency electromagnetic waves from the opening obliquely downward, Since the object to be heated is irradiated like a sprinkler together with the rotation, the drawback that the bottom of the object to be heated is usually difficult to be heated is eliminated. Therefore, thawing of frozen foods, which has been considered difficult in the past, is uniformly heated, and the bottom does not remain iced.

Further, high-frequency heating by a tall container for milk or sake cans does not heat the upper part, and there is almost no temperature difference between the upper and lower parts.

Since the table is provided with a plurality of symmetrical radio wave passage openings, the high-frequency electromagnetic wave emitted downward is reflected by the bottom of the heating chamber and passes through the radio wave passage opening to irradiate the bottom of the object to be heated. The heating of the bottom of the heated object is not weak.

Further, the constricted portion does not become abnormally hot even if the upper constricted load such as Choshi is applied.

Since the high frequency electromagnetic wave from the power supply port is directly applied to the load, the performance does not deteriorate even if the heating chamber is slightly distorted.

Further, even a small number of objects to be heated can efficiently absorb high-frequency electromagnetic waves, resulting in good heating efficiency.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of a high frequency heating apparatus according to an embodiment of the present invention.

FIG. 2 is a central sectional view of the same high-frequency heating device.

FIG. 3 is a plan view of the table 17.

[Explanation of symbols]

 2 Turntable 4 Power supply port 9 Stirrer 10 Radiating groove 15 Stirrer reflector 17 Table 18 Radio wave passage port

Front page continued (72) Inventor Takayuki Akashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A heating chamber for heating an object to be heated in a main body,
A high-frequency oscillator that generates high-frequency electromagnetic waves in the heating chamber,
A waveguide for guiding the high-frequency electromagnetic wave of the high-frequency oscillator to the heating chamber and a table for freely rotating the object to be heated,
A stirrer for stirring the high-frequency electromagnetic wave in the heating chamber is provided, the waveguide accommodates the stirrer, the stirrer rotates on a horizontal rotating shaft, and the power supply port of the waveguide is provided in the heating chamber. The stirrer is disposed on a side wall, and the stirrer has a plurality of substantially V-shaped radiation grooves, and when the radiation grooves face the high frequency oscillator side in the waveguide, the high frequency waves are provided above and below the radiation grooves. A high-frequency heating device, characterized in that a stirrer reflector that reflects electromagnetic waves is provided, and the height of the upper stirrer reflector is higher than that of the lower reflector. 2. The high-frequency heating device according to claim 1, wherein the table is made of metal and has a plurality of radio wave passages other than the center of rotation, and the radio wave passages are symmetrical with respect to the table. .