JPS5935392A - Door unit for 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 reducing the weight and cost of a door device for a high-frequency heating device.

Conventional structure and its problems For example, in a conventional microwave oven door device, the cross-sectional views of which are shown in FIGS. ) and a 1/4 wavelength choke are essential, so either a large and heavy door is required as shown in Figure 1, or a complicated mechanism is required around the heating chamber as shown in Figure 2. It was either that or not. Originally, a single metal plate could be used as a microwave oven door, and by attaching hinges, handles, etc. to the plate, it would be possible to fulfill the door's function. However, since there is a desire to see through the door and into the heating chamber during cooking, a method has been widely adopted in which small holes are drilled in a metal plate as a means of letting light through and blocking radio waves. is inserted, and both sides are protected by transparent plates to prevent large amounts of radio wave leakage.

In addition, if a reliable metal contact could be made between the heating chamber opening facing the door and the door, chalk would not be necessary. Chalk is required in case a napkin gets stuck in the door.

This chalk and screen will be explained in detail based on FIGS. 1 and 2.

FIG. 1 shows a cross-sectional view of the door 1, which includes a frame 2 made of iron plate with a thickness of about 1 mm, a screen 3 made of iron plate with a thickness of about 0.2 mm,
This example includes a glass transparent plate 4 provided on both sides of the screen 3, a polypropylene resin chalk cover 6, and the like. The frame 2 is a large rectangular drawn product, with a rectangular opening 6 in the center and a wadding recess 7 all around the opening 6, with a thickness of about 0.8 layer inside the recess 7. A periodic structure 8 made of a steel plate is attached by spot welding, and a mounting bracket 10 having an opening 9 of the same size as the opening 6 is attached just outside the opening 6 by spot welding. The mounting bracket 10 and the periodic structure 8 are painted in a welded state. The screen 3 is fixed with screws 12 while being sandwiched between the screen fixing fittings 11 made of iron plate and the mounting fittings 10 having a size of approximately one inch. A hole larger than the screw 12 in the screen 3 and the fixing metal fitting 11, and a hole larger than the screw 12 in the mounting metal fitting 10
Drill a hole smaller than screw 12 in advance and secure it with the screw. One of the two transparent plates 4 is sandwiched and fixed between the mounting bracket 10 and the screen 3, and the other one is sandwiched between the screen 3 and the screen fixing bracket 11. The fixing fitting 11 has an opening 13 of the same size as the opening 6 of the frame 2, and the screen 3 is provided with a group of small holes 14 for viewing through the opening 6 in a slightly narrower area. Further, in FIG. 1, the heating chamber wall 16 and heating chamber opening periphery 17 of the heating chamber 15 are indicated by two-dot chain lines, and the inside of the heating chamber is indicated by diagonal lines. Now, in the method shown in FIG. 1, the heating chamber is viewed through the small hole group 14 made in the screen 3 and the glass transparent plate 4 provided on both sides of the hole group, and the chalk is connected to the frame 2, the mounting bracket 10, Fixing bracket 11 and mounting bracket 1
The recess 7 of the frame 2, which is surrounded by the screen 3 sandwiched between the frame 2 and the fixing metal fittings 11, plays this role.

The periodic structure 8 is provided to improve the radio wave leakage prevention performance of this choke.

In the example shown in FIG. 2, the door 1 has a screen 3 made of a thin iron plate sandwiched therebetween, and has a transparent plate 18 made of glass on one side and a transparent plate 18 made of a thin polycarbonate resin sheet on the other side.
These three plates have almost the same external dimensions, and in order to fix the three plates, an aluminum sash 19 is provided around the entire circumference, and the screen 3 has a small hole 14 for seeing through.
The group is opened. This door 1 is provided with a see-through function, but is not provided with a choke. Although the heating chamber wall 16 and the heating chamber opening periphery 17 are shown with two-dot chain lines, the opening periphery 1
A recess 7 is provided around the entire circumference of the recess 7, and the inside thereof is filled with polypropylene resin 20, which has a choke function.

As you can clearly see by comparing Figures 1 and 2 above, if the choke function is not provided on the door 1, the door 1 will be complicated.
If the heating chamber 15 is increased in weight and provided on the heating chamber 15 side, the heating chamber 15 will become complicated.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to reduce the size and weight of the choke function.

Structure of the Invention In order to achieve the above object, the door device of the high frequency heating device of the present invention is made by forming three thin films A, C, and B in order on a transparent dielectric plate such as glass. From the frame-shaped film eK, insulate the ends of b to a conductive film, bring the ends into contact with β on the inside of the frame of film C, and further insulate at least one of A and b on the inside of the film C. The membranes A and B, which are insulated by C, have a choke function. Therefore, it is possible to realize a lightweight, small-sized microwave oven door device having a choke function. .

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

FIG. 3 is a sectional view of a main part of the door 1 shown in comparison with the conventional example shown in FIGS. 1 and 2, and FIG. 4 is an exploded plan view showing the order in which the coating is formed. A transparent dielectric plate 4 made of heat-strengthened glass is shown in FIG. 39. A copper film 3S shown in FIG. 3 is deposited at the position indicated by the two-dot chain line in FIG. 3. The central portion of the copper coating 3B shown in FIG. 3 has a mesh shape in which a large number of small holes 14 are formed. A dielectric film 20g shown in FIG. 3C is printed at the position indicated by the two-dot chain line on this FIG. 3 screen. This dielectric film 20s is made of ultraviolet curing type epoxy 7 resin, and is cured by irradiating ultraviolet rays after printing. Next, a copper film 1111 shown in FIG. 3d is deposited. Dielectric film 2
For the positional relationship with 0g, the position of the dielectric film 20B is shown in Figure 3d.
Indicated by a two-dot chain line.

The previously deposited copper film 3S contacts the inside of the dielectric film 20s at the thinly notched portion shown in FIG. 3d. As is clear from the figure, the copper film 11fl has a shape in which slits 21 are periodically cut on the outer periphery.

Next, the copper coatings 3s and 11g and the dielectric coating 20B 3
A transparent polyester film 18 is applied over the layer film. The external size is the same as that of the transparent dielectric plate 4 shown in FIG. 3a, and the surface with the transparent adhesive is fixed in direction to the three layer side.

In FIG. 6, the end faces of the transparent dielectric 4 and the polyester film 18 are covered with an aluminum sash 19 for protection and also used for fixing the hinge 22. The sash and hinge are both screwed together using holes 23 and 24 drilled at corresponding positions.The operation of the above configuration will now be described.

FIG. 6 shows an enlarged view of the section ■ in FIG. 4. In this figure, it is assumed that there is a radio wave E1 trying to leak from inside the heating chamber 15 to the outside through the gap 125 between the door 1 and the heating chamber opening periphery 17. This radio wave E1 travels upward on FIG. Since the two conductive films 3S and 11s are insulated with a dielectric film of 20 g, part of the radio wave E1 is E2.
enters this. Since the copper films 38 and 11B are in contact with and electrically connected to each other inside the frame of the frame-shaped dielectric film 20s, the radio wave E2 is reflected here and returns.

This returned component radio wave E3 merges with the radio wave E1 again, but as is well known, the copper films 3s and 11s and the dielectric film 20s are appropriately applied so that the radio waves E1 and E3 cancel each other out. If the dimensions are set, the radio wave E1 will not leak to the outside or will be weakened.

The see-through function consists of a mesh-shaped part with many small holes 14 and a transparent dielectric material 4 made of tempered glass that sandwiches this from both sides.
and polyester film 18.

In this embodiment, a polyester film 18 is used to protect the three layers of film, but the polyester film 18 is not necessarily necessary, and for example, a flier lacquer or the like may be used.In short, as long as a transparent dielectric layer is formed. good. ′＝
! In addition, these protective coatings may be omitted at the cost of some durability.

In this embodiment, the shell 19 is used to protect the edge of the tempered glass 4 and to attach the hinge 24, but if the edge protection is sacrificed and the hinge 24 is also fixed by adhesive, etc., the shell 19 can be fixed. becomes unnecessary.

In this example, the external size of the three-layer film is copper film 3B.
〉Dielectric coating 20S〉Copper coating 11s, but copper coating II
@If 3s and 11g are insulated, radio waves can enter between them and the choke function will work.

FIG. 7 is an exploded plan view showing the order of forming a film in another embodiment. The only difference from the example shown in FIG. 4 is ``A'' and ``D'' in the same figure. In the example of the trench shown in FIG. 4, the mesh portion in which the small holes 14 are provided is in the same figure, and in the example in FIG. The portion is located in the copper film 11g in d of the same figure, and the corresponding position in the figure is an opening.

Further, in Fig. 7, d is vapor-deposited copper in this example, but any other film may be used as long as it has good conductivity.
For example, the contact portion between the copper films 3S and 11s may be bonded with copper foil using a conductive adhesive, or may be printed with carbon.

Effects of the Invention According to the present invention, a door device for a high-frequency heating device having a choke function and a see-through function can be made small and lightweight, and
Each film can be manufactured by methods such as vapor deposition and printing, so it can be manufactured at low cost.

[Brief explanation of drawings]

Figures 1 and 2 are sectional views of essential parts of a conventional door device, Figure 3 is a sectional view of essential parts of a door device according to an embodiment of the present invention, and Figures 4 a - e are A plan view of the main parts of the device, Figure 6 shows the door, 3g,
11g... Copper coating (Coating A. Figure 1 Figure 2 Wild Goose 3 Figure/9 Ce)
(c) (cL) (Taj

Claims (1)

Claims: A transparent dielectric, thin films A and B, and a dielectric film, wherein the films A and B and the dielectric film are formed on the transparent dielectric. A dielectric film and a film B (7) are stacked in this order, and the films A and B are conductive, and the dielectric film has a frame-like shape, and the films A and B are in contact with each other on the inside of the frame shape. At the same time, the coatings A and B are formed on the inside of the frame shape.
At least one of the door devices has a transparent mesh pattern and a high-frequency heating device.