JPS628689B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to reduce the weight and thickness of a microwave oven door.

Conventional microwave oven doors are made by pressing and welding iron plates with a thickness of around 1 mm, as it is necessary to construct a 1/4 wavelength choke inside the door to prevent radio wave leakage of the microwave oven. Thickness is also 2cm
or more, it was heavy and required a dielectric material to block the entrance to the chiyoke. Figure 3 is a cross-sectional view of the main parts of a conventional general microwave oven door, including a frame 1 made of iron plate, two pieces of tempered glass 2, a punching plate 3 made of thin iron plate, and a back plate made of enameled iron plate. 4 and a chiyoke cover 5 made of synthetic resin.

The present invention is an improved door from the viewpoints of resource saving, weight reduction, and thickness reduction, and embodiments thereof will be described below with reference to the drawings. FIG. 1 is a perspective view of a door in one embodiment of the present invention, as seen diagonally from above. In the figure, reference numeral 11 denotes a door body made of transparent polycarbonate with a thickness of about 3 mm, and three fixing holes 12 are bored in a vertical row on the left side of the door body. Furthermore, 15 round holes 13 are arranged in a rectangular shape. The door body 11 is sandwiched and bonded between a front plate 21 and a back plate 31 made of two stainless steel thin plates. Front plate 21 and back plate 31
Both have the same external dimensions and are made of stainless steel plates with a thickness of about 0.2 mm, and the front plate 21 has a large rectangular peephole 22 in the center to form a bezel, and there are 15 holes around this peephole 22. round hole 23
is open. This round hole 23 is located in the door body 11.
It is provided at a position that completely corresponds to the round hole 13. The only difference between the back plate 31 and the front plate 21 is that, instead of the square holes 22 in the front plate, a group of punching holes 32 for see-through purposes are provided at the positions thereof. With the door body 11 sandwiched between the front plate 21 and the back plate 31 in a sandwich-like manner as shown in Fig. 1,
The three parts are fixed together with aluminum rivets 41 passed through the round holes 23 and 13. Needless to say, at this time, the front plate 21 and the back plate 31 are electrically connected. (See Figure 2).

With the above configuration, a resource-saving door that is lightweight and thin is completed. In other words, the front plate 21, the back plate 31, and the aluminum rivet 41, each made of two stainless steel plates, form a 1/4 wavelength chain. The interior of this yoke is filled with polycarbonate, which is the main body of the door, and as is well known, the size of the yoke can be reduced.

Furthermore, as can be seen by comparing Figures 2 and 3,
The entrance direction of the heating chamber is toward the back side in the conventional figure 3, and toward the outer periphery of the door in figure 2, so the opening of the heating chamber (the part blocked by the door)
For the conventional door shown in Figure 3, a flat surface is sufficient, but for the door shown in Figure 2, a metal frame facing the outer periphery of the door may be provided around the opening of the heating chamber. It is valid. In other words, in the conventional door shown in FIG. 3, the metal picture frame does not have a great effect on the characteristics of the doorway, but in the present invention, the metal picture frame can face parallel to and closer to the entrance of the doorway. , has a large influence on the characteristics of the yoke, and designing this to an appropriate value is an effective and important factor.

FIG. 2 is a cross section taken along the line -' in FIG. 1, and when compared with FIG. 3, it is clear that the number of parts is reduced, and in particular, since there is no steel plate frame 1, the weight can be significantly reduced.

Also, since the stainless steel plate with a thickness of about 0.2 mm is weak, it was conventionally protected with two pieces of glass as shown in Figure 3, but in this example, it is glued to the door body. Therefore, it has sufficient strength.
Note that the adhesive includes Cemedine 3000 (trademark) and the like.

In the present invention, the door body is not limited to polycarbonate, but may be made of a transparent, heat-resistant material, such as a tempered glass plate, and screws and nuts may be used instead of the aluminum rivets 41.

As described above, according to the present invention, a lightweight and thin microwave oven door can be realized, which is extremely useful for saving resources.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a microwave oven door according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line -' in Fig. 1, and Fig. 3 is a sectional view of main parts of a conventional door. . 11... Door body made of transparent dielectric material, 21...
...Front plate, 22...Peephole, 31...Back plate,
32...Punching hole group, 41...Aluminum rivet.

Claims (1)

[Scope of Claims] 1. A transparent dielectric plate, a front plate with a frame-shaped cutout in the center and a back plate with a punched center formed of a thin metal plate, as the two metal plates. A door for a microwave oven, characterized in that a transparent conductive plate is placed between the plates, and the front plate and the back plate are electrically connected by a plurality of metal rods passing through the three plates. 2. The microwave oven door according to claim 1, wherein the front plate and the back plate are made of stainless steel plates.