JP3534074B2 - High frequency heating equipment - Google Patents

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 for dielectrically heating an object to be heated using high frequency energy.

[0002]

2. Description of the Related Art A conventional high-frequency heating apparatus has a structure mainly for uniform heating of an object to be heated, a turntable mechanism for rotating the object to be heated, a stirrer mechanism for stirring high-frequency waves in a heating chamber with a radio wave reflecting blade. Japanese Patent Fair 1-4862
And the like rotary waveguide mechanism for rotating the waveguide coupled with a high frequency which is fed as described in 9 JP.

On the other hand, in recent years, along with changes in lifestyle,
There is an increasing tendency to actively use ready-made delicacies and frozen foods for daily menus. Therefore, there is a demand for a high-frequency heating device that can cook a large amount at one time and that has good uniform heating properties.

Further, in recent years, in order to improve the quality of cooking, a method of heating while monitoring the food temperature with an infrared sensor has become widespread. However, a high frequency heating device having a structure capable of accurately reading the temperature of food with an infrared sensor has been developed. Is desired.

[0005]

A stirrer system or a rotating waveguide system is a system capable of uniformly heating a large number of foods at a time and accurately reading the food temperature by an infrared sensor. The reason is that unlike the turntable method, the food does not rotate and moves, so the food can be placed on the bottom of the heating chamber (mostly a rectangular parallelepiped).
In addition, because there is no movement of food, there is little variation in detection by the infrared sensor and the temperature can be read accurately.

However, in general, the stirrer system
Even in the rotating waveguide method with excellent stirring ability and good uniform heating performance, there is a problem that uniform heating performance deteriorates when the rotating waveguide rotation area becomes smaller than a certain ratio with respect to the heating chamber bottom area. It was From the viewpoint of safety and cleanability, it is desirable to install the rotating waveguide inside the narrowed part provided on the bottom of the heating chamber without exposing it inside the heating chamber, and to close the opening with some kind of dielectric material. Also, the narrowed part needs to be as small as possible. Further, considering a case where a heater is installed on the bottom surface of the heating chamber to constitute a high frequency heating device with a heater function, it is desired that the rotating waveguide and the narrowed portion are as small as possible in order to improve the heater distribution performance.

The present invention solves the above-mentioned conventional problems, and is an excellent high frequency heating in which the uniform heating performance does not deteriorate even when the rotating area of the rotating waveguide becomes smaller than a certain ratio to the bottom area of the heating chamber. The purpose is to provide a device.

[0008]

In order to solve the above-mentioned conventional problems, a high-frequency heating apparatus according to the present invention has a heating chamber for accommodating an object to be heated and an opening formed in a bottom surface of the heating chamber.
A truncated cone-shaped diaphragm portion, a radio wave radiating means having directivity provided in the diaphragm portion, an exciting portion installed outside the center of the diaphragm portion and radio-wave coupled to the radio wave emitting means, and the radio wave emitting means. And a drive means for rotationally driving, wherein the radio wave radiation means is composed of a rotary waveguide and
Part of the radiated radio waves are reflected by the inclined surface of the diaphragm and the rest
The upper surface of the rotating waveguide should pass through the upper surface of the diaphragm for radio waves.
The structure is located above the opening .

Since the upper surface of the rotating waveguide is located above the bottom surface of the heating chamber, a part of the radio waves radiated from the waveguide is reflected on the inclined surface of the diaphragm part and the rest of the radio waves is on the upper surface of the diaphragm part. The two types of radio wave radiation paths that pass through the chamber and are reflected by the side surface of the heating chamber are provided to enhance the stirring effect in the heating chamber. As a result, it is possible to provide an excellent high-frequency heating device in which uniform heating performance does not deteriorate even if the rotating waveguide rotating area becomes smaller than a certain ratio with respect to the heating chamber bottom area.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 is a heating chamber for accommodating an object to be heated, and an opening is formed on the bottom surface of the heating chamber.
A truncated cone-shaped diaphragm portion formed, a radio wave radiating means having directivity provided in the diaphragm portion, and an exciting portion installed outside the center of the diaphragm portion and radio-wave coupled to the radio wave emitting means,
The radio wave emitting means has a driving means for rotationally driving the radio wave emitting means, and the radio wave emitting means is composed of a rotating waveguide and is configured to rotate.
Some radio waves radiated from the wave tube are reflected by the inclined surface of the diaphragm.
The remaining radio waves are configured such that the upper surface of the rotary waveguide is located above the opening so as to pass through the upper surface of the diaphragm . By locating the upper surface of the rotating waveguide above the bottom of the heating chamber, some of the radio waves radiated from the rotating waveguide are reflected by the inclined surface of the diaphragm part and the rest of the radio waves pass through the upper surface of the diaphragm part and are heated. By creating two types of radio wave radiation paths that reflect on the chamber side surface, the stirring effect in the heating chamber is enhanced. As a result, it is possible to provide an excellent high-frequency heating device in which uniform heating performance does not deteriorate even if the rotating waveguide rotating area becomes smaller than a certain ratio with respect to the heating chamber bottom area.

According to a second aspect of the invention, the object to be heated is stored.
Heating chamber and a throttle provided on the bottom of the heating chamber,
A radio wave radiating means having directivity provided in the diaphragm part,
It is installed outside the center of the diaphragm and can be used in
And drive the excitation unit coupled to the radio wave emitting means.
A driving means, and the radio wave radiating means comprises a rotating waveguide
And the upper surface of the rotating waveguide is above the bottom surface of the heating chamber.
The heater is installed around the narrowed portion outside the heating chamber, and the heater is excellent in both high-frequency heating performance and high-frequency heating performance.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a first embodiment of the high-frequency heating apparatus of the present invention, in which (a) is a plan view of the bottom of the heating chamber and (b) is AA 'in the plan view. FIG.

In FIG. 1, the heating chamber 1 is a thin plate-shaped substantially rectangular parallelepiped shape, and a frusto-conical drawing portion 3 is formed by drawing in the vicinity of the center of the bottom surface 2, and the opening of the drawing portion 3 is formed. A sealing means 4 made of a glass-based or ceramic-based material is provided, and the periphery is fixed with a ceramic-based adhesive. At the center of the bottom surface of the throttle unit 3, a high-frequency excitation unit 5 for supplying power to the heating chamber 1 is provided. The high frequency generated by the magnetron (not shown) is guided to the excitation unit 5 via the waveguide 6. A motor 7 as a driving unit is attached to the lower side of the excitation unit 5 with its output shaft inserted in the waveguide 6.

The rotary waveguide 8 which is a radio wave radiating means is made of a sheet metal fan shape, and is fixed to the fan-shaped upper surface portion 8a and side blade portions 8b, 8b which are adjacent to the bottom surface of the throttle portion 3 on the left and right sides of the fan. A pair of tetrafluoroethylene spacers 8c that slide on the bottom surface of the portion 3, a tail portion 8d that is also close to the bottom surface of the throttle portion 3 in the vicinity of the fan, and a sheet metal fixed near the tail portion 8d of the upper surface 8a. It is composed of a drawn antenna shaft 8e. The antenna shaft 8e penetrates the excitation unit 5 and is inserted and fitted to the output shaft of the motor 7. The rotary waveguide 8 has a configuration in which the fan-shaped left and right wing portions 8b and the tail portion 8d suppress the propagation of high frequencies in that direction and transmit the high frequencies in the direction of the fan-shaped widened portion. The height of the rotary waveguide 8 is determined so that the fan-shaped upper surface portion 8a is located above the bottom surface 2 of the heating chamber 1.

The heater 9 is a sheathed heater, and comprises a circumferential portion 9a and a pair of lead portions 9b extending to the left side in the figure. The circumferential portion 9a is located outside the bottom surface 2 and has a narrowed portion 3
Is fixed in contact with the bottom surface 2 near the outside of the upper end of the. Therefore, the inner diameter of the circumferential portion 9a is made slightly larger than the outer diameter of the upper end of the throttle portion 3. On the side wall 10 of the heating chamber 1, a pair of left and right shelves 11 formed in a convex shape by drawing is provided, and a heated object mounting base 12 made of a ceramic material drawn by a chain double-dashed line is mounted on this.

The operation and action of the high-frequency heating device of the present invention constructed as above will be described below.

FIG. 2 shows the uniform heating performance of the high-frequency heating apparatus of the present invention. Fifteen frozen Shumai were used as the objects to be heated. Frozen in a freezer (about -20
C.) Frozen Shumai were arranged in a ceramic dish having a height of 10 mm and an outer diameter of 190 mm as shown in FIG. 2 and wrapped so as to cover the whole with a wrap film for food packaging. Rotating waveguide 8 with the start of cooking
Was rotationally driven by the motor 7 (35 revolutions per minute), and at the same time, high frequency power was supplied. After heating for 4 minutes and 10 seconds, the temperature of each of 15 Shumais was measured by a thermometer after the heating was completed. The result is shown in FIG. In FIG. 2, A indicates that the upper surface 8a of the rotary waveguide 8 is located below the bottom surface 2 of the heating chamber 1, and B indicates that the upper surface 8a of the rotary waveguide 8 of the present invention is the heating chamber bottom surface 2.
The case where it is located above is shown. In A, the difference between the maximum temperature and the minimum temperature after heating of frozen Shumai was 34 ° C, but in B, it was only 9 ° C, and it can be said that B is superior in uniform heating performance.

From the figure, it was found that the high frequency heating uniformity was remarkably improved by arranging the rotary waveguide upper surface 8a above the heating chamber bottom surface 2. By locating the upper surface of the rotating waveguide above the bottom of the heating chamber, some radio waves radiated from the rotating waveguide are reflected by the inclined surface of the diaphragm part and the rest of the radio waves pass through the upper surface of the diaphragm part. By creating two types of radio wave radiation paths that are reflected by the side surfaces, the stirring effect in the heating chamber is enhanced. By this action, an excellent high-frequency heating device can be obtained in which the uniform heating performance does not deteriorate even if the rotating waveguide rotating area becomes smaller than a certain ratio with respect to the heating chamber bottom area.

Further, since the rotary waveguide can be made small, the throttle portion for installing the rotary waveguide can be made small. Therefore, the means for closing the aperture of the throttle portion becomes small, and the high-frequency heating device with good cleaning of the heating chamber is provided. can do. Furthermore, since the narrowed portion can be made small, a heater can be installed outside the narrowed portion, and a high-frequency heating device with a good heater function can be realized.

The shape of the heating chamber used in the examples of the present invention was 367 mm in width, 320 mm in depth and 235 mm in height, and the diameter of the aperture of the aperture was 165 mm and the depth of aperture was 20.
mm. Further, regarding the shape of the radio wave radiating means 8, the distance from the center of rotation to the root of the fan shape is 27.5 mm, the width thereof is 80 mm, the radius of the fan-shaped spreading portion from the rotation center is 68 mm, and the spreading angle is 40. Degree, side wing height is 20m
m. The clearance between the side wings and the bottom of the throttle is 5
mm.

[0022]

As described above, by locating the upper surface of the rotary waveguide above the bottom surface of the heating chamber, a part of the radio waves radiated from the rotary waveguide is reflected on the inclined surface of the diaphragm portion and the rest of the electric wave is reflected. The radio waves pass through the upper surface of the diaphragm and are reflected by the side surface of the heating chamber. By thus forming two types of radio wave radiation paths, the stirring effect in the heating chamber is enhanced. This makes it possible to provide an excellent high-frequency heating device in which uniform heating performance does not deteriorate even when the rotating area of the rotating waveguide becomes smaller than a certain ratio with respect to the bottom area of the heating chamber.

Further, since the rotary waveguide can be made small, the throttle portion for installing the rotary waveguide can be made small. Therefore, the means for closing the aperture of the throttle portion becomes small, and the heating chamber can be cleaned easily and safely with high frequency heating. It can be a device. Furthermore, since the narrowed portion can be made small, a heater can be installed outside the narrowed portion, and a high-frequency heating device with a good heater function can be realized.

[Brief description of drawings]

FIG. 1A is a plan view of a heating chamber of a high frequency heating apparatus according to a first embodiment of the present invention, and FIG. 1B is a sectional view taken along the line AA ′ of the plan view.

FIG. 2 is a diagram showing uniform heating characteristics of the high-frequency heating device.

[Explanation of symbols]

1 heating chamber 2 bottom 3 throttle 5 Excitation section 7 Motor (drive means) 8 Rotating waveguide (radio wave radiating means) 8a Rotating waveguide upper surface 9 heater

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-225393 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05B 6/76 F24C 7/02 H05B 6 / 64

Claims (2)

(57) [Claims] 1. A heating chamber for accommodating an object to be heated, a frustoconical throttle portion having an opening formed in the bottom surface of the heating chamber, a throttle portion provided on the bottom surface of the heating chamber, and an inside of the throttle portion. A radio wave radiating means having directivity, an exciting section that is installed outside the center of the diaphragm section and is radio-wave coupled to the radio wave radiating means, and a driving means that rotationally drives the radio wave radiating means.
Wherein together gyrus radio emission means is constituted by a rotary waveguide
Some of the radio waves radiated from the waveguide are reflected by the inclined surface of the diaphragm.
A high-frequency heating device configured such that the upper surface of the rotary waveguide is positioned above the opening so that the remaining radio waves are emitted through the upper surface of the diaphragm . 2. A heating chamber for containing an object to be heated and the heating.
A throttle part provided on the bottom surface of the chamber and an orientation provided in the throttle part
Installed in the center outside of the diaphragm part.
And an excitation section that is electromagnetically coupled to the radio wave emitting means,
The electric wave radiating means has a driving means for rotationally driving,
The wave radiating means is composed of a rotating waveguide
With a structure in which the upper surface of the tube is located above the bottom surface of the heating chamber,
A high frequency heating device in which a heater is installed around the narrowed portion outside the heating chamber.