JPS5986192A - High frequency heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high frequency heating device equipped with a turntable.

Conventional structure and problems As a means to prevent uneven baking in high-frequency heating equipment, stirrer fans and turntables are installed in the heating chamber. Especially in the case of the stirrer fan method, the front, back, left and right sides of the heating chamber are In order to easily obtain uniformity of the electric field, power is supplied from approximately the center of the top surface of the heating chamber. An example of this method will be explained based on the drawings. FIG. 1 is a longitudinal cross-sectional view of the conventional high-frequency heating device, in which 1 is a main body having a heating chamber 2 inside, 3 is a magnetron that generates high-frequency waves, and is a guide. An opening 6 provided approximately in the center of the wave tube 4 and the top surface of the heating chamber 2
is supplied to the heating chamber 2 via the stirrer shaft 7.
A stirrer fan pivotally supported rotates when the magnetron 3 is activated and stirs the high frequency waves passing through the opening 6. Reference numeral 8 represents a dish holder on which the object to be heated 9 is placed, and 10 represents a partition plate made of a low dielectric material.

It is known that by providing the opening 6 at approximately the center of the top surface of the heating chamber in this manner, the left and right balance of the electric field within the heating chamber can be easily maintained, thereby improving the distribution performance.

However, the above configuration tends to have the following drawbacks.

(1) When heating the object by placing it on the center of the plate holder, for example, if the container is narrow and has a height component, such as a milk bottle or a sake bottle, it is close to the opening 6. High frequency waves are directly radiated near the upper part of the heated object, creating a strong electric field, which tends to cause local heating, making it difficult to use.

(2) In order to compensate for the drawback of (1) above, it is necessary to use auxiliary means such as wrapping aluminum foil over the object to be heated, which takes time and effort.

(3) In order to save the effort in (2) above, a configuration may be considered in which a reflective plate made of metal is provided so that high frequency waves are not directly radiated near the partition plate 10 above the object to be heated, but if misused If it is operated without load, there is a risk of sparking with the stirrer fan, etc.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a high-frequency heating device that improves distribution performance and is easy to use.

Structure of the Invention In order to achieve the above object, the high frequency heating device of the present invention is provided with a turntable at the bottom of the heating chamber, and the approximate center of the opening provided on the top of the heating chamber is located between the top of the heating chamber and the side wall of the heating chamber near the magnetron. When divided into thirds parallel to the magnetron, it is installed on the far side from the magnetron.Even if the container width of the object to be heated is narrow and there is a height component, local heating is difficult to occur without auxiliary means, and the waveguide is Due to its long configuration, long-line effects are likely to occur, and the output fluctuation characteristics at light loads are improved, and even in the unlikely event of no-load operation due to misuse, it has the effect of preventing any negative effects on the magnetron. It is.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that the same numbers are given to parts with the same functions as those of the conventional example.

FIG. 2 is a longitudinal cross-sectional view of the high-frequency heating device of the present invention.
3 is a main body having a heating chamber 2 therein; 3 is a magnetron that generates high frequency waves; the high frequency waves are supplied to the heating chamber 2 through a waveguide 6 and an opening 6 provided on the top surface of the heating chamber 2; In addition,
The approximate center of the opening 6 connects the top surface of the heating chamber 2 with the magnetron 3.
When the heating chamber 2 is divided into three equal parts parallel to the side wall surface near the magnetron, it is installed on the side far from the magnetron. 10 is a partition plate made of a low dielectric material that closes the opening 6; 11 is a turntable provided at the bottom of the heating chamber 2 on which a plate pedestal 8 on which the object to be heated 9 is placed is placed; and 12 is a heating chamber. 2 is a turntable drive source that drives the turntable 11 from outside. 13
is a concave constriction provided on the side wall surface of the heating chamber 2 on the opening 6 side.

In the above configuration, when the magnetron 2 is activated, the turntable drive source is also activated and the turntable 11 is rotated. The high frequency waves generated by the magnetron 3 are supplied from the waveguide 4 to the heating chamber 2 through the opening 6, but at this time, the approximate center of the opening 6 is located close to the magnetron 3 in the heating chamber 2.
When divided into three parts, the magnetron 3
Since the heating chamber 2 is located far from the heating chamber 2, the high frequency waves radiated into the heating chamber 2 are diffusely reflected on the heating chamber side wall surface having the concave diaphragm 13 and then absorbed by the heated object 9, so that the heating chamber 2 is uniformly heated. Cheap. Note that if the approximate center of the opening 6 is removed from the approximate center of the top surface of the heating chamber, the electric field in the front, rear, left, and right directions within the heating chamber will be non-uniform, but since the object to be heated is moved around by the turntable, the heating process is relatively uniform. I can do it.

Therefore, according to the present embodiment, even when a container having a narrow width and a height component, such as a milk bottle or a sake bottle, is placed in the center of the plate holder 8, the high frequency waves radiated from the opening 5 are directly transmitted to the object to be heated. It is difficult to hit the upper part of the body, and local heating is less likely to occur. An example of this effect is shown in Table 1.

Comparison of upper and lower temperature differences in milk bottles Table 1 Note that when the object to be heated 9 is placed around the plate holder 8, it is possible that the object to be heated 9 passes directly under the opening 5; Since the time between the passages 11.1 and 11.1 is short compared to the time it takes for the heated material 9 to go around the heating chamber 2 once, there is no problem that would affect the distribution performance. i! In addition, as is clear from the above configuration, the length of the waveguide 4 is longer than the conventional one, so the long line effect is likely to occur, and the load fluctuation characteristics are good. It also has the effect of shortening the heat treatment time.

Comparison of cooking time under light load (eoow output)
Table 2 Furthermore, even if the main body is operated in a no-load state, the long line effect reduces abnormal heat generation due to the reflector on the magnetron and reduces the risk of sparks and the like.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) When heating an object by placing it on the center of a plate holder, local heating is less likely to occur in cases where the container has a narrow width and height component, such as a milk bottle or a sake can made from a sake bottle.

(2) Due to the effect of (1) above, it is necessary to use auxiliary means such as covering the top of the object to be heated with aluminum foil, and sparks can be generated by interposing a reflective plate made of metal between the opening and the object to be heated. The danger is also an honor.

(3) The long-line effect is easily promoted and the load fluctuation characteristics are good <Z, a. The time for light-load heat treatment, which is frequently used in actual use, can be shortened and efficiency can be improved. Furthermore, when the main body is operated with no load, the reflected waves to the magnetron are alleviated and the magnetron is protected.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a conventional high-frequency heating device, and FIG. 2 is a vertical cross-sectional view of a high-frequency heating device according to an embodiment of the present invention. 1...Main body, 2...Heating chamber, 3...
... Magnetron, 4... Waveguide, 6...
... Opening, 8 ... Dish holder, 9 ... Heated object, 11 ... Turntable, 12 ...
... Turntable drive source, 13... Heat chamber side wall concave aperture. Name of agent: Patent attorney Toshio Nakao / 11 or 1 person Figure 1 Figure 2

Claims (2)

[Claims] (1) A main body that has a heating chamber inside, a magnetron that emits high frequency waves, a waveguide that guides the high frequency waves generated by the magnetron to the heating chamber, and a waveguide installed on the top surface of the heating chamber to take the high frequency waves into the heating chamber. υ'1? fLl
; The high-frequency heating device is configured such that the approximate center of the opening is located on the side far from the magnetron when the top surface of the heating chamber is divided into three equal parts parallel to the side wall surface of the heating chamber near the magnetron. (2) The high-frequency heating device according to claim 1, wherein a concave diaphragm is provided on a side wall surface of the heating chamber adjacent to the opening.