JPS6319998B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to weight reduction and cost reduction 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 chiyoke are essential.
Therefore, either a large and heavy door is required, as shown in FIG. 1, or a complicated mechanism is required around the heating chamber, as shown in FIG. 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 the heating chamber through the door during cooking, a method of drilling small holes in a metal plate as a means of letting light through and blocking radio waves has been widely adopted, and wires etc. are inserted into these small holes. is,
Both sides are protected by transparent plates to prevent large amounts of radio wave leakage.

In addition, if reliable metal contact could be made between the heating chamber opening facing the door and the door, there would be no need for a cheese yoke. A chiyoke is required in case a napkin gets stuck in the door.

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

Figure 1 shows a cross-sectional view of the door 1, including 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, transparent plates 4 made of glass provided on both sides of the screen 3, and polypropylene resin. This example is made of a Chiyoke cover 5 made by Manufacturer. The frame 2 is a large rectangular drawn product, with a rectangular opening 6 in the center and a recess 7 all around the opening 6.
A periodic structure 8 made of a steel plate of about 0.8 mm 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 a screen fixing fitting 1 made of iron plate with a thickness of about 1 mm.
1 and the mounting bracket 10, and is fixed with screws 12. A hole larger than the screw 12 in the screen 3 and the fixing bracket 11, and a hole larger than the screw 12 in the mounting bracket 1.
Pre-drill a hole smaller than screw 12 in 0 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 has a group of small holes 14 for seeing through the screen 3 in a slightly narrower area due to the opening 6. Further, in FIG. 1, the heating chamber wall 16 of the heating chamber 15 and the heating chamber opening periphery 17 are indicated by two-dot chain 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 yoke includes the frame 2, the mounting bracket 10, The recess 7 of the frame 2, which is surrounded by the fixing metal fitting 11 and the screen 3 sandwiched between the mounting metal fitting 10 and the fixing metal fitting 11, fulfills this role. The periodic structure 8 is provided to improve the radio wave leakage prevention performance of this yoke.

In the example shown in Fig. 2, the door 1 has a screen 3 made of a thin iron plate sandwiched between them, and there is 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. The plates have approximately the same external dimensions, and in order to fix the three plates, an aluminum sash 19 is provided around the entire circumference, and a group of 14 small holes for seeing through the screen 3 are bored. Although this door 1 is provided with a see-through function, it is not provided with a ceiling. Heating chamber wall 1
6 and the heating chamber opening periphery 17 are shown by two-dot chain lines, a recess 7 is provided around the entire circumference of the opening periphery 17, and the inside is filled with polypropylene resin 20, which has a yoke function.

As can be clearly seen by comparing Fig. 1 and Fig. 2 above, if the heating function is not provided on the door 1, the door 1 will be complicated and heavy, and if it is provided on the heating chamber 15 side, the heating chamber 15 will be complicated. I'm getting used to it.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to reduce the size and weight of the chiyoke 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 formed by sequentially stacking three thin films A, C, and B on a transparent dielectric plate such as glass.
The conductive film A is formed by the dielectric frame-shaped film C.
Insulate the ends of and B, and insulate the ends of A and B on the inside of the frame of coating C.
and B are brought into contact with each other, and at least one of A and B is meshed on the inside, and the other is formed with an opening in a portion corresponding to the mesh or the mesh of the film of the mesh. Insulated film A
and B have a check function, so that it is possible to realize a light and compact microwave oven door device having a check 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. 4a. A copper film 3s shown in FIG. 3b is deposited at the position shown by the two-dot chain line in FIG. 4a. The central portion of the copper coating 3s shown in FIG. 4b has a mesh shape in which a large number of small holes 14 are formed. A dielectric film 20s shown in FIG. 4c is printed at the position shown by the two-dot chain line on this FIG. 4b. This dielectric film 20s is made of an ultraviolet curing type epoxy resin, and is cured by irradiating ultraviolet rays after printing. Next, a copper film 11s shown in FIG. 4d is deposited. Regarding the positional relationship with the dielectric film 20s, the position of the dielectric film 20s is shown by a two-dot chain line in FIG. 4d. The previously deposited copper film 3s is the dielectric film 2.
Contact is made inside 0s at the thinly hatched area in Figure 4d. As is clear from the figure, the copper film 11s has a shape in which slits 21 are periodically cut on the outer periphery. Next, a transparent polyester film 18 is applied over the three layers of copper films 3s and 11s and dielectric film 20s. The external size is the same as that of the transparent dielectric plate 4 shown in FIG. 3a, and the transparent dielectric plate 4 is fixed with the surface coated with transparent adhesive facing the three layers.

In FIG. 5, the end faces of the transparent dielectric 4 and the polyester film 18 are covered and protected by an aluminum sash 19, which is also used to fix the hinge 22. Both the sash and the hinge are screwed together using holes 23 and 24 drilled in corresponding positions. The operation of the above configuration will be explained below.

FIG. 6 shows an enlarged view of a portion of FIG. 3. In this figure, it is assumed that there is a radio wave E ₁ that attempts to leak from inside the heating chamber 15 to the outside through the gap 25 between the door 1 and the heating chamber opening periphery 17 . This radio wave E ₁ travels upward on Figure 6. Copper film 3s and 11
Since the two conductive films s are insulated by the dielectric film 20s, part of _{the radio wave E 1 enters} into them. Since the copper films 3s and 11s are in contact with and electrically connected 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 radio wave _E1 and
If the copper films _3s and 11s and the dielectric film 20s are made to have appropriate dimensions so that the electromagnetic waves E3 and E3 cancel each other out, the radio wave _E1 will not leak to the outside or will be weakened.

The see-through function is achieved by a mesh-like part having a large number of small holes 14, and a transparent dielectric material 4 made of tempered glass and a polyester film 18 that sandwich this part from both sides.

In this embodiment, a polyester film 18 is used to protect the three layers of the film, but the polyester film 18 is not necessarily necessary, and for example, a flexible film may be used, as long as a transparent dielectric film is formed. . Further, these protective films may be omitted if durability is sacrificed to some extent.

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

In this example, the external dimensions of the three layers of coatings are as follows: copper coating 3s>dielectric coating 20s>copper coating 11s; however, if the copper coatings 3s and 11s are insulated, radio waves will enter between them. and the chiyoke function works.

FIG. 7 is an exploded plan view showing the order of forming a film in another embodiment. The only difference from the example in FIG. 4 is b and d in the same figure. In other words, in the example shown in Fig. 4, the mesh portion in which the small holes 14 are provided is at b in the same figure;
The corresponding position in figure d is an opening, but in the example of figure 7, the mesh part is in the copper coating 11s in figure d, and the corresponding position in figure b is an opening. .

In addition, in FIGS. 7b and 7d, copper is vapor-deposited in this embodiment, but other coatings may be used as long as they have good conductivity. For example, the contact area between the copper coatings 3s and 11s is coated with a conductive adhesive. Copper foil may be bonded using , or carbon may be printed.

Effects of the Invention As described above, according to the present invention, a door device for a high-frequency heating device having a check 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 the drawing]

1 and 2 are sectional views of main parts of a conventional door device, FIG. 3 is a sectional view of main parts of a door device according to an embodiment of the present invention, and FIGS. 4 a to 4e are main parts of the same device. 5 is an exploded perspective view of the sash and hinge of the device, FIG. 6 is an enlarged cross-sectional view of a portion of FIG. 3, and FIGS. 7a to 7e are door devices according to other embodiments of the present invention. FIG. 1... Door, 3s, 11s... Copper film (film A, B), 4... Transparent dielectric, 15... Heating chamber,
20s...Dielectric film (C).

Claims (1)

[Claims] 1 comprising a transparent dielectric, thin films A and B, and a dielectric film, wherein the films A and B and the dielectric film are stacked on the transparent dielectric in the order of the film A, the dielectric film, and the film B; Said film A
and B is conductive, and the dielectric film has a frame-like shape, and is in contact with the films A and B on the inside of the frame, and one of the films A and B is on the inside of the frame. A door device for a high-frequency heating device, in which one has a net-like pattern for see-through purposes, and the other has an opening formed in a portion corresponding to the net-like pattern of the net-like pattern or the net-like pattern of the film.