JPH06302382A - High frequency heating device - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a high-frequency heating device,
It is an object of the present invention to suppress heating unevenness of the food 4 and to provide a means 13 for detecting the temperature of the food 4 by the surface wave heating method to accurately control the heating of the food. A conductor line that heats a food 4 by propagating a high frequency from an oscillation source 2 that oscillates a high frequency with a surface wave, and has a variable mechanism 6 that changes the electric field strength of the surface wave of the conductor line 5 depending on the type of the food 4. The detection means 13 for detecting the temperature of the food 4 on the conductor line 5 is provided. With this configuration,
By controlling the concentration of the electric field on the food 4, uneven heating of the food 4 can be suppressed, and the temperature of the food 4 can be accurately controlled, so that cooking with good finish can be performed.

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 heating food.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional high-frequency heating apparatus heats a food 4 by radiating a high frequency from a high-frequency oscillator 2 into a closed space in which the entire heating chamber 1 is surrounded by metal. There is. Therefore, the food 4 is heated in the heating chamber 1 in the standing wave mode 10 generated by the heating chamber. Further, the food 4 is put into and taken out of the heating chamber 1, and in order to confirm the heating state of the food 4, the door 4 (not shown) is provided with punching holes so that the high frequency does not leak outside. The turntable 11 is provided to improve the heat distribution of the food 4 in the heating chamber 1. Thus, the food 4 was heated from the inside by high frequency vibration. Further, in order to automate the reheating of the food 4, the oscillation source 2 is controlled by detecting the gas such as vapor generated from the food 4 by the detection means 12 or the like. On the other hand, apart from such a standing wave mode heating method, there is also a heating method in which an electric field is concentrated near the food by surface wave heating (for example, Japanese Patent Publication No. 47-37878).

[0003]

However, the above-mentioned FIG.
In the conventional configuration, there is a problem that even if the distribution in the heating chamber 1 is improved by the turntable 11, unevenness occurs due to the standing waves in the heating chamber 1 and dissatisfaction occurs. Further, the detection means 1 used for automating the reheating of the food 4
2 is to detect the gas such as steam that exceeds 4O0C where food 4 boils. Therefore, the automation of milk (temperature at the time of drinking 65C) or sake can (40C) that is detected before boiling is appropriate time. The first problem is that it is impossible to accurately control to a target temperature due to the difference in environmental conditions.

In addition, when the food 4 is heated by the surface wave, there is a second problem that the electric field strength and the heating distribution cannot be accurately controlled unless the spacing between the conductor lines for exciting the surface wave and the design variation of the dimension are managed. there were.

The present invention solves the above-mentioned first problem, and it is a first object of the present invention to provide a high-frequency heating device which can uniformly control the temperature of food by heating the whole food uniformly by the surface wave heating method. The second object is to provide a high frequency heating device capable of stably controlling the surface wave excitation in order to solve the second problem.

[0006]

In order to solve the first problem, the present invention covers an oscillation source that oscillates a high frequency, a conductor line that propagates the high frequency as a surface wave to heat food, and a conductor line. A dielectric on which food is placed, a variable mechanism that changes the electric field strength of the surface wave of the conductor line depending on the type of food, a heating chamber,
The configuration is such that detection means for detecting the temperature of the food on the conductor line and control means for controlling the output of the oscillation source by the signal of the detection means are provided.

In order to solve the second problem,
An oscillation source that oscillates a high frequency, a conductor line that propagates a high frequency by a surface wave to heat food, a dielectric that molds the conductor line integrally and puts food on it, and the electric field strength of the surface wave of the conductor line depending on the type of food The variable mechanism for changing the temperature, the heating chamber, the detecting means for detecting the temperature of the food on the conductor line, and the controlling means for controlling the output of the oscillation source by the signal of the detecting means are provided.

[0008]

According to the first aspect of the present invention, the function of uniformly heating food by the variable mechanism for varying the electric field concentration on the conductor line and the function of accurately detecting the temperature of the food contacting the conductor line are provided. Have.

According to the second aspect of the present invention,
Since the conductor line and the dielectric are integrated, there is little variation in the conductor line and stable excitation is possible.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, 1 is a heating chamber,
2 is a magnetron which is a high frequency oscillation source, 3 is a power source for supplying to the magnetron, 4 is food, 5 is a conductor line for causing surface wave heating, 6 is a variable mechanism for changing the intensity of surface wave heating, and 7 is a conductor line 5. An antenna for exciting the high frequency wave from the magnetron 2, 8 a cooling fan for cooling the magnetron 2, 9 a dielectric covering the conductor line and carrying the food 4, and 13 a temperature sensor as a detecting means for detecting the temperature of the food 4. , 14 are control means for receiving the signal from the temperature sensor 13 and controlling the magnetron 2, the variable mechanism 6, etc.
Reference numeral 5 denotes an openable / closable lid having a radio wave shielding mechanism covered with a conductive film.

2 and 3 are explanatory views for explaining the principle of surface wave heating. The surface wave heating utilizes total reflection of radio waves, and by constructing an interdigital conductor line as shown in FIG. 2, radio waves can be concentrated on the surface of the conductor line. FIG. 3 is an equivalent circuit thereof, in which the characteristic impedance is Z0, the lumped impedance is Z1, the length 1 of the conductor line, the phase constants of the respective spaces are β0 and βp, and the phase constant in the Z direction is βz, and the conductor line is If the pitch is p, then the characteristic equation at that time is: cosβzp = cosβzp + (Z1 / 2Z0) · sinβpβ = (2π) / λ.

In the interdigital conductor line shown in FIG. 2, if the line length l is appropriately selected with respect to the wavelength λ of the operating frequency, it is possible to control the transmission of radio waves traveling at right angles to the transmission direction Z. This is because the spatial impedance changes depending on the line length l, and the transmission and blocking of radio waves can be controlled.

Therefore, by providing the variable mechanism 6 that appropriately changes the line length of the conductor line 5, the variable mechanism 6 is controlled according to the type of the food 4, and the electric field is localized and transmitted to a certain part. It can be transmitted to the whole. With this configuration, in the surface wave heating method, the electric field can be freely controlled, so that heating unevenness of food does not occur. By the way, at this time, in order to prevent the electric wave from leaking into the free space, the dielectric 9
Radio waves are not emitted to the human body by the lid 15 having the radio wave shielding mechanism which can be opened and closed. Also, the temperature sensor 1
3, the temperature rise of the food 4 on the dielectric is detected. When the desired temperature is reached depending on the type of the food 4, the control means 14 automatically stops the oscillation of the magnetron 2 or the like.

(Embodiment 2) In FIG. 4, 1 is a heating chamber,
2 is a magnetron which is a high frequency oscillation source, 3 is a power source for supplying to the magnetron, 4 is food, 5 is a conductor line for causing surface wave heating, 6 is a variable mechanism for changing the intensity of surface wave heating, and 7 is a conductor line 5. An antenna for exciting a high frequency wave from the magnetron 2, 8 a cooling fan for cooling the magnetron 2, 9 a dielectric body on which conductor lines are integrally etched and on which the food 4 is placed, and 13 detection means for detecting the temperature of the food 4. Is a temperature sensor, 14 is a temperature sensor 13
Is a control means for controlling the magnetron 2, the variable mechanism 6 and the like, and 15 is a lid having a radio wave shielding mechanism which can be opened and closed. The control of the electric field for surface wave heating is the same as in Example 1. The conductor line 5 has a pattern formed by printing on the back surface of the dielectric 9 on which the food 4 is placed, and the variable mechanism 6 controls so that the pattern of the printed line can be changed. Further, in the surface wave heating method, the electric field is strongest near the conductor line, and the electric field exponentially decreases as the distance from the line increases. Since it is heated, efficient excitation is possible.

[0016]

As described above, the high frequency heating apparatus of the present invention has the following effects.

(1) The variable mechanism for varying the electric field concentration on the conductor line can control the heating of the food uniformly, and the detection means for detecting the temperature of the food can accurately detect the temperature of the food. It is possible to provide a high-frequency heating device that is easy to use.

(2) Since the conductor line is integrally formed by printing on the dielectric material on which food is placed, variations in the design of the conductor line can be suppressed, so that stable and efficient surface wave heating can be realized by high frequency heating. A device can be provided.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a high-frequency heating device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a conductor line for explaining surface wave heating according to the first and second embodiments of the present invention.

FIG. 3 is an equivalent circuit diagram for explaining surface wave heating according to the first and second embodiments of the present invention.

FIG. 4 is an overall configuration diagram of a high frequency heating device according to a second embodiment of the present invention.

FIG. 5 is an overall configuration diagram of a conventional high-frequency heating device.

[Explanation of symbols]

 1 Heating Chamber 2 Oscillation Source 4 Food 5 Conductor Line 6 Variable Mechanism 9 Dielectric 13 Detecting Means 14 Control Means

Claims (2)

[Claims] 1. An oscillation source that oscillates a high frequency, a conductor line that propagates the high frequency as a surface wave to heat food, a dielectric that covers the conductor line and places the food, and the conductor line depending on the type of the food. A high frequency wave composed of a variable mechanism for changing the electric field strength of the surface wave of, a heating chamber, a detection means for detecting the temperature of the food in the conductor line, and a control means for controlling the output of the oscillation source by the signal of the detection means. Heating device. 2. An oscillation source for oscillating a high frequency, a conductor line for propagating the high frequency as a surface wave to heat food, a dielectric having the conductor line for mounting the food, and the conductor depending on the kind of the food. It comprises a variable mechanism for changing the electric field strength of the surface wave of the line, a heating chamber, a detection means for detecting the temperature of the food on the conductor line, and a control means for controlling the output of the oscillation source by the signal of the detection means. High frequency heating device.