JPS6143835B2 - - Google Patents

Description

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

Periodic structures have been adopted as a means of improving radio wave leakage prevention performance. As shown in FIG. 1, these have a three-dimensional structure and are made up of a door outer peripheral cavity part A, a slit part B, etc., so they inevitably become large and heavy. In other words, since it is based on a 1/4 wavelength chain, at 2.450MHz, which is used in microwave ovens, each side is approximately 30mm in size, so the metal plate that makes up this must also be approximately 1mm thick. It becomes heavy.

The present invention leads to this and makes it lighter, and one embodiment thereof will be explained below with reference to FIG.

In FIG. 2, a transparent plate 1 is a chemically strengthened plate glass having a thickness of 5 mm, and has a plurality of holes 2 formed on its outer periphery. The back plate 3 facing the heating chamber is made of a stainless steel plate with a thickness of 0.2 mm, and its outer dimensions are slightly smaller than the transparent plate 1. Further, slits 4 having a width of about 2 mm are provided periodically on the four sides of this back plate 3. Inside thereof, a plurality of holes 5 are provided at positions corresponding to the holes 2. Furthermore, a group of small holes 6 for see-through purposes are drilled in a rectangular area inside the rectangular area. The front plate 7 is made of the same material and the same dimensions as the back plate 3, and the holes 8 are provided in the same position and the same size as the holes 5. Furthermore, a large hole 9 is made at the position where the small hole group 6 is provided. Both the front plate 7 and the back plate 3 are plated with black chrome on both sides. Penetrate the holes 2, 5, and 8 in the three plates with metal objects (not shown) such as aluminum rivets or screw nuts.
The two plates are fixed, and the front plate 7 and the back plate 3 are electrically connected via a metal body. Further, the transparent plate 1 is adhesively fixed to the front plate 7 and the back plate 3. With the above configuration, a small and lightweight microwave oven door is realized. Front plate 7
and the back plate 3 are electrically connected to each other by a metal body, so that a chiyoke with an opening at the outer periphery is formed. Since the back plate 3 has slits 4 provided at equal intervals, the radio wave leakage prevention performance is further improved. The inside of this cheese yoke is filled with glass, and as is well known, a waveguide filled with a dielectric material with a permittivity of ε can be made to have a dimension of 1/√, so this cheese yoke is also similar. Can be made smaller. Although the mechanical strength of the slit 4 portion of the back plate 3 is weak, sufficient strength can be maintained because one side is protected by a transparent plate 1 made of tempered glass and bonded. Also, since the position corresponding to the small hole group 6 is the transparent plate 1 and the square hole 9, it is visible through this door. Furthermore, as can be seen from Figure 2, the door can be constructed with only three parts, excluding the metal body for fixation.

As described above, according to the present invention, a small, lightweight, and resource-saving microwave oven can be realized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of a conventional door, and FIG. 2 is an exploded perspective view showing an embodiment of the present invention. 1... Transparent plate, 3... Back plate (metal plate), 7...
Front plate (metal plate), 4...Slit, 6...Small hole group, 9...Square hole (hole).

Claims (1)

[Claims] 1 Sandwich the transparent dielectric plate with metal plates on both sides, pass a metal rod through these three plates, electrically connect the metal plates on both sides with the metal rod, and one metal plate connects to the outer periphery. A door for a microwave oven, characterized in that periodic slits are provided in the metal plate, a group of small holes for seeing through is provided on the inside, and holes are bored in the other metal plate at positions corresponding to the groups of small holes on the inside. .