JPS5912594A - 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 the Invention The present invention relates to a radio wave leakage prevention structure for a door of a high frequency heating device.

Structure of the conventional example and its problems The door of the conventional high frequency heating apparatus shown in FIG. 4 had the following problems.

(1) The door frame 5 constituting the cavity, the door, and the heating chamber 2 are brought into high-frequency contact to completely prevent leakage of radio waves, and the door frame 5 and the heating chamber 2 are fixed to each other with tightening screws 18. This tightening screw 18 is structurally located on the heating chamber 2 side of the door 4, so when cleaning food scraps, meat juice, oil, etc. scattered in the heating chamber 2, clean the area around this mounting screw 18. There was a problem that made it very difficult to solve. In addition, if cleaning was insufficient, food particles could become carbonized and sparks caused by high frequency waves could occur.

(2) Since the valley that constitutes the entire cavity is large, the see-through window of the door 4 is small, making it difficult to monitor the object to be heated throughout the heating chamber 2, which poses a problem in terms of usability.

0) Since there are many components for preventing radio wave leakage of the door 4, there are large variations in the assembly of the door 4, and a stable effect of preventing radio wave leakage cannot be obtained.

OBJECTS OF THE INVENTION It is an object of the present invention to improve the usability of the device by improving the conventional structure described above, and to improve the radio wave leakage prevention performance.

Structure of the Invention In order to achieve the above object, the high-frequency heating device of the present invention performs the first step of preventing radio wave leakage in the door frame that is in high-frequency contact with the peripheral surface of the front opening of the heating chamber, and simplifies the structure of the door. This has excellent effects such as improving visibility through the door and preventing sparks caused by food particles.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, a heating chamber 2 with an opening on one side is located inside the main body 1, and a door 4 body is attached to the opening of the heating chamber 2 so that it can be opened and closed by operating a handle 3. is located.

An object to be heated is placed in the heating chamber 2 and dielectrically heated by high frequency waves emitted from a magnetron 7 (not shown).

Next, the main body of the door 4, which is the main part of this structure, will be explained.

The door frame 6, which is made of a metal body and has a hole in the center for seeing through the object to be heated, forms the frame of the door 4 body and has many small holes. The first step is to prevent radio wave leakage. Further, together with a slit plate 7 made of a metal body and having slits perpendicular to the main body of the door 4, a first cavity 8 and a second cavity 9 are constituted to perform the second stage of radio wave leakage prevention.

At this time, the first cavity 8 is filled with a dielectric 10 in order to simplify the structure of the cavity and to make the viewing window of the door frame 5 as wide as possible. The substantial length of the cavity when the dielectric 10 is placed in the cavity is expressed by the following formula.

λ: v5 Wavelength of electric material λ0: Wavelength of high frequency in vacuum εr: Relative permittivity The dielectric 1o can be made of synthetic resin such as polypropylene, which has low dielectric loss and is easy to mold.In this case, the relative permittivity εr is 2 to 3, and the wavelength is 1.4 to 1.
7 and the cavity size is the same as the conventional A b-30.
The mm has become smaller, and the cavity structure has changed from the conventional L-shape to a 1-shape, making it possible to create a simpler structure.

In the present embodiment 10, the second cavity 9 has a dielectric material 1.
Although the synthetic resin body corresponding to 0 is not provided, this cavity part does not need to be applied to the present embodiment because there is little leakage of cylindrical frequency waves due to the prevention of radio wave leakage in the third stage.

In the structure of the door 4 main body, the surface of the door frame 5 in contact with the heating chamber 2 and the surface 6 around the opening of the heating chamber 2 have a heating chamber 2
A transparent polyester film 11 is pasted on the door frame 5 to prevent dust or food particles from adhering to the door frame 5, and the peripheral edges are held against the dielectric 10. It is being

Note that the dielectric 10 has a hook 13 in the hole 12 of the slit plate 7.
is fixed and incorporated.

Reference numeral 14 denotes a door screen, which is held between the door frames 5 by a door outer body 15 constituting the outside Vt of the side door 4 body, and the door outer body 15 is fixed to the door frame 5 with screws 16.

Effects of the Invention The following effects were obtained by making the cavity simple and using a heat-resistant plastic film.

(1) The tightening screws etc. on the heating chamber side of the door body can be eliminated, and even if the door is dirty with food scraps, oil, etc., it can be easily cleaned, and the sparking phenomenon of food scraps caused by shattered high frequency waves has also been solved. done. 1(2)
The area around the door that corresponds to dimension C in Figure 4, which is the conventional row, can be made smaller as shown in dimension 9 in Figure 2, and the transparent window of the door is also wider than before, allowing you to see the entire heating chamber more clearly. Improved usability.

(3) Prevention of leakage waves (The number of Q components is reduced, and the variation in dimensions during assembly is reduced, making it possible to obtain stable leakage prevention performance.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a high-frequency heating device which is an embodiment of the present invention, and FIG. 2 is a sectional view taken along line xx' in FIG. 1.
FIG. 3 is an exploded perspective view of the main part of the door body of the same device, and FIG. 4 is a sectional view of the main part of the door main body of the conventional high-frequency heating device. 2... Heating chamber, 4... Door, 5...
...door frame, 6...opening surrounding surface, 7.
... Slit plate, 8 ... First cavity, 9 ... Second cavity, 1o ... Dielectric, 11 ... Polyester film, 14・
...Door screen. Name of agent: Patent attorney Toshio Nakao and one other person Figure 1 Figure 2! ? Figure 3 7 ~ [

Claims (1)

[Claims] (1) A heating chamber for storing an object to be heated, and a door attached to an opening of the heating chamber so as to be openable and closable, the door being in high-frequency contact with the surrounding surface of the opening and having a large number of small holes. a metal slit plate provided in a cavity formed in an outer peripheral wall of the door frame, and a door screen provided on the outside of the door frame; A high frequency heating device which is divided into a first cavity and a second cavity by a slit plate, and further includes a galvanic metal body provided inside at least one of the cavities. (a) The high-frequency heating device according to claim 1, wherein a heat-resistant plastic film is attached to the heating chamber side of the door frame.