JP2003109744A - High frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent high frequency heating device capable of highly efficient and stable power feeding and yet with small installation space. SOLUTION: The shape of a waveguide 15 installed on the bottom face of a heating room 14 is made V-shaped, bent 45 to 70 deg. against the bottom face of the heating room, so that, high frequency loss at the bent part of the waveguide is drastically reduced, and highly efficient and stable oscillation can be maintained. Further, by the waveguide 15 set aslant, a high frequency oscillator 13 can be effectively set between an outer box/the heating room/a heater unit to enable diminution of a setting space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables high-efficiency and stable power supply in a high-frequency heating apparatus for inductively heating an object to be heated by using high-frequency energy, which has a structure in which high-frequency power is supplied from the bottom of a heating chamber. Moreover, the present invention provides a high-frequency heating device that can reduce the installation space of the device compared with the conventional one.

[0002]

2. Description of the Related Art A high-frequency heating apparatus has the following structure to obtain uniform heating performance: a turntable system for rotating an object to be heated, a stirrer for stirring high-frequency waves in a heating chamber with a radio wave reflecting blade. Method or special fair 1
As described in JP-A-486299, a rotary waveguide system is provided in which a rotary waveguide, which is a radio wave emitting means coupled to a high frequency to be fed, is installed at the bottom of a heating chamber to rotate the waveguide. Among them, the rotating waveguide method is particularly excellent in uniform heating performance and has an advantage that the food placing table in the heating chamber can be widely used on a flat surface.

Many of conventional rotary waveguide systems capable of uniformly heating a large number of cooked foods at once have a structure as shown in FIG. FIG. 2 is a front sectional view of a conventional high-frequency heating device. The operation will be described below. The high frequency generated from the high frequency oscillator 1 is transmitted to the excitation port 4 of the heating chamber 3 through the waveguide 2.
The excitation port 4 and the heating chamber 3 are coupled in high frequency by a coaxial antenna 5, and the high frequency is transmitted to the rotary waveguide 6 which is a radio wave radiating means. The rotary waveguide 6 has an opening 6a at its end, and radiates a high frequency wave from the opening 6a into the heating chamber 3 with directivity. Further, since the rotary waveguide 6 is rotationally driven by the motor 7, the high frequency waves emitted from the openings 6 a of the rotary waveguide 6 are agitated to every corner of the heating chamber 3 and become uniform. Therefore, the object to be heated placed on the pan support 8 made of a low-loss dielectric placed above the rotary waveguide 6 is uniformly heated.

As shown in FIG. 2, the conventional arrangement of components of the rotary waveguide system is such that the high frequency oscillator 1 is placed in the heating chamber 3 as shown in FIG.
High frequency is propagated to the excitation port 4 of the bottom 3a of the heating chamber by the linear waveguide 2 installed next to the high frequency heating device. Therefore, the horizontal width of the high frequency heating device is increased by the width of the high frequency oscillator 1 and the installation space is increased. Further, as shown in FIG. 3 which is a side sectional view of a conventional high frequency heating device, when an oven function is added to the high frequency heating device, a heater 9a and a blower fan 9b for blowing the heat of the heater to the heating chamber are provided in the rear part 3b of the heating chamber. It is necessary to install the heater unit 9 provided with the above. Therefore, the depth of the high-frequency heating device becomes large, and the installation space becomes even larger.

As a countermeasure for this, there is a method of installing a high frequency oscillator 10 under a heating chamber 11 as shown in FIG. 4 which is a side sectional view of a high frequency heating device having an L-shaped waveguide. FIG. 5 is a front view of the same device (the door is omitted)
As shown in FIG. 3, the total height of the device is increased, but the width of the device can be reduced. Therefore, when the depth of the device is the same as in FIG. 3, the installation space can be reduced. However, in this method, the waveguide 12
Has an L-shape that bends at a right angle, and there is a problem that the high-frequency propagation loss at the bend is large and the high-frequency heating efficiency is significantly deteriorated. Moreover, since the distance (T1) between the antenna 10a of the high-frequency oscillator 10 and the bent portion 12a of the waveguide cannot be made large, the matching between the high-frequency oscillator 10 and the heating chamber 11 is remarkably deteriorated, and an unstable and inefficient oscillation state is likely to occur. . If T1 is set to a large value, stability is increased, but the overall height of the device becomes large, which is a design problem.

[0006]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art, and it is highly efficient and stable in a system in which radio wave radiation means is installed at the bottom of the heating chamber and power is supplied from the lower part of the heating chamber to the heating chamber. It is an object of the present invention to provide a high-frequency heating device that enables the above-mentioned power supply and can reduce the installation space of the device as compared with the conventional one.

[0007]

In order to solve the above-mentioned conventional problems, a high-frequency heating apparatus according to the present invention comprises a high-frequency oscillator, a heating chamber for housing an object to be heated, and a high-frequency oscillator oscillated by the high-frequency oscillator. And a radio wave radiation means provided at the bottom of the heating chamber, which is coupled to the waveguide in a high frequency manner,
The waveguide has a driving means for rotationally driving the radio wave radiating means, and the waveguide is installed at the bottom of the heating chamber and is 45 to 70 degrees with respect to the bottom of the heating chamber.
It is a structure that is bent and bent.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a high frequency oscillator, a heating chamber for accommodating an object to be heated, a waveguide for guiding the high frequency oscillated by the high frequency oscillator to the heating chamber, and the waveguide. A radio wave radiating means that is coupled to the wave tube in a high frequency manner and is provided at the bottom of the heating chamber, and the waveguide is installed at the bottom of the heating chamber and has a V-shaped configuration with respect to the bottom of the heating chamber. is there. Since the waveguide is formed in a V-shape with respect to the bottom of the heating chamber, compared to the L-shaped waveguide, there is less high-frequency propagation loss in the bent portion, and stable and highly efficient power feeding is possible. Installation space can be reduced compared to a wave tube.

According to a second aspect of the present invention, there is provided a high frequency oscillator, a heating chamber for containing an object to be heated, a waveguide for guiding the high frequency oscillated by the high frequency oscillator to the heating chamber, the waveguide and the high frequency. And a drive means for rotationally driving the radio wave radiating means, wherein the waveguide is installed at the bottom of the heating chamber and is relative to the bottom of the heating chamber. It has a <shape> configuration that is bent at 45 to 70 degrees. Since the waveguide is bent in the direction of 45 to 70 degrees with respect to the bottom of the heating chamber, it has less high-frequency propagation loss at the bend compared to the L-shaped waveguide, and stable and highly efficient power supply is possible. In addition, the installation space can be reduced as compared with the linear waveguide.

According to the third aspect of the present invention, the high frequency oscillator is provided in the outer box, the heating chamber, and the heater by providing the heater unit having the heater and the blowing fan on the rear surface of the heating chamber, and the waveguide is inclined. The units can be efficiently placed between the units and the installation space can be reduced.

According to a fourth aspect of the present invention, the radio wave radiating means is constituted by a rotating waveguide, so that the distance T from the antenna of the high-frequency oscillator to the bent portion of the high-frequency oscillator is greater than that of an L-shaped waveguide. Since it can be made large, the heating chamber and the high-frequency oscillator can be easily matched with each other, and a highly efficient and stable oscillation state can be maintained.

[0012]

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

(Embodiment 1) FIG. 1 is a side sectional view of a first embodiment of a high frequency heating apparatus of the present invention.

In FIG. 1, the high frequency wave generated from the high frequency oscillator 13 is installed in the bottom portion of the heating chamber 14 and is guided by a waveguide 15 having a "<" shape and bent by A degrees with respect to the heating chamber bottom surface 14a. Is transmitted to the excitation port 16 of. In the first embodiment, the waveguide bending angle A is 60 degrees. The excitation port 16 and the heating chamber 14 are coupled to each other in a high frequency manner by the coaxial antenna 17, and the high frequency wave is transmitted to the rotary waveguide 18 which is a radio wave radiating means. The rotary waveguide 18 has an opening 18a at its end, and radiates a high frequency into the heating chamber 14 from the opening 18a with directivity. Further, since the rotary waveguide 18 is rotationally driven by the motor 19, the rotary waveguide opening 18a is formed.
The high-frequency waves emitted from the heating chamber 14 are agitated to every corner of the heating chamber 14 and become uniform. Therefore, the object to be heated placed on the plate pedestal 20 made of a low-loss dielectric placed on the upper portion of the rotary waveguide 18 is uniformly heated without unevenness.

In such a structure, since the waveguide 15 has a V-shape bent by 60 degrees with respect to the bottom surface 14a of the heating chamber, the high-frequency loss in the bent portion 15a of the waveguide has an L-shape bent at a right angle. According to the experiment, the effect is significant when the bending angle is 70 degrees or less, which is significantly smaller than that of the waveguide. Further, by making the antenna oblique, the antenna bending portion 15a from the antenna 13a of the high frequency oscillator 13 is bent.
Since the distance T2 up to is larger than that of the L-shaped waveguide, the heating chamber 14 and the high-frequency oscillator 13 can be easily matched with each other, and a highly efficient and stable oscillation state can be maintained. In this embodiment, T1 is 53 mm and T2 is 25 mm in the case of the L-shaped waveguide shown in FIG. Further, in order to add an oven function to the high-frequency heating device, a heater unit 21 having a heater 21a and a blower fan 21b is attached to the rear portion 14b of the heating chamber. Heater unit 21, outer box 22, heating chamber 1
It became possible to arrange it efficiently among the four. As a result, the width of the apparatus can be narrowed and the installation space can be reduced as compared with the conventional high frequency heating apparatus shown in FIG. If it is inclined at 45 degrees or more, it becomes easy to store the high frequency generator in the lower part of the heating chamber. The high-frequency heating apparatus of the present invention has an installation space reduced by about 12% compared to the conventional linear waveguide type apparatus shown in FIG.

In the first embodiment, the bending angle A of the waveguide is 60 degrees, but as described above, A is 45 degrees.
If it is between 70 degrees, the effect of the present invention is effective.

Although the first embodiment describes the case where the radio wave radiation means installed at the bottom of the heating chamber is a rotary waveguide,
The effect of the present invention is effective even with other radio wave emitting means (stirrer, rotating antenna, etc.).

[0018]

As described above, according to the high frequency heating apparatus of the present invention, the shape of the waveguide installed on the bottom of the heating chamber is bent by 45 to 70 degrees with respect to the bottom of the heating chamber. Therefore, the high-frequency loss in the bent portion of the waveguide is significantly smaller than that of the L-shaped waveguide bent at a right angle.
Also, by making it oblique, the distance T from the antenna of the high-frequency oscillator to the bent portion of the waveguide can be made larger than that of the L-shaped waveguide, so that the heating chamber and the high-frequency oscillator can be easily matched and highly efficient and stable. The oscillation state can be maintained. Also, by sloping the waveguide, the high-frequency oscillator can be efficiently placed between the outer box, heating chamber, and heater unit, and the installation space can be reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view of a high-frequency heating device according to a first embodiment of the present invention.

FIG. 2 is a front sectional view of a conventional high-frequency heating device.

FIG. 3 is a side sectional view of a conventional high-frequency heating device.

FIG. 4 is a side sectional view of a conventional high frequency heating device equipped with an L-shaped waveguide.

FIG. 5 is a front view of a conventional high-frequency heating device equipped with an L-shaped waveguide.

[Explanation of symbols]

13 High frequency oscillator 14 heating chamber 15 Waveguide 18 Rotating Waveguide (Radio Wave Emitting Means) 19 Drive means

Claims (4)

[Claims] 1. A high frequency oscillator, a heating chamber for accommodating an object to be heated, a waveguide for guiding the high frequency oscillated by the high frequency oscillator to the heating chamber, and the heating chamber coupled to the waveguide in a high frequency manner. A high frequency heating apparatus comprising a radio wave radiating means provided at a bottom portion, wherein the waveguide is installed at a bottom portion of the heating chamber and is bent in a V shape with respect to a bottom surface of the heating chamber. 2. A high-frequency oscillator, a heating chamber for accommodating an object to be heated, a waveguide for guiding the high frequency oscillated by the high-frequency oscillator to the heating chamber, and the heating chamber coupled to the waveguide in a high frequency manner. The wave guide is provided on the bottom of the heating chamber, and the wave guide is provided at the bottom of the heating chamber.
A high-frequency heating device having a <-shaped> configuration that is bent 5 to 70 degrees. 3. The high-frequency heating device according to claim 1, further comprising a heater unit provided with a heater and a blower fan on the rear surface of the heating chamber. 4. The high frequency heating apparatus according to claim 1, wherein the radio wave radiating means is a rotating waveguide.