JPS60175395A - 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 The present invention relates to an improvement in the radio wave leakage prevention structure of a door provided at the entrance of a heating chamber of a gastric frequency heating device so as to be openable and closable.

For example, the conventional high frequency heating device is
2 (Fig. 1), the peripheral wall of the radio wave maze G and I-1 provided on the periphery of the door 2 (moving in the direction of the dotted arrow) is brought into plane contact with the flange B that surrounds the entire periphery of the opening of the heating chamber 5. In addition, since the entrances 16 of the radio mazes G and H were opposed to the flange A, the opposing area between the door 2 and the flange O was large. Therefore, the external dimensions of the door 2 become large, and the ratio of the volume of the heating chamber 5 to the total volume of the high-frequency heating device increases.

In other words, the space factor was bad. Note that 8 is a door rear plate, and 10 is a door front plate.

Therefore, the present invention was made in view of the above points, and an object thereof is to provide a high-frequency heating device that maintains the radio wave sealing effect, which is the basic function of the door, has a small external dimension of the door, and has a good space factor. do. For this reason, a sash that surrounds the entire circumference of the door is provided at right angles to the flange, and the entrance is placed opposite to it, and a number of metal pieces are jutted inward from the front panel of the door that faces the entrance, and these pieces are arranged periodically.

Next, the structure and operation of the high frequency heating device of the present invention will be explained with reference to the drawings.

FIG. 2 is a front view showing one embodiment of the high frequency heating device of the present invention. Reference numeral 1 indicates an operation panel 1, for example, a timer 1a for setting the heating time, an output selector switch 1b for switching high frequency output, and a cooking switch 1 for starting high frequency heating.
c, a door open switch 1d for opening the door, etc. are provided. 2 is a door that can be opened and closed, and 6 is a satshu that surrounds the door 2 at a slight distance from the door 2.

FIG. 6 is a sectional view of the vicinity of the peripheral edge of the door 2, viewed from the direction of the arrow AB in FIG. 4 is an outer box, 5 is a heating chamber, 6 is a flange that surrounds the entire opening of the heating chamber 5, and 7 is a sash 3.
This is a screw for attaching the flange to the flange. Satsush 3.
Outer box 4. The heating chamber 5° and the flange 6I'i are each made of a metal plate. The satush 6 surrounds the entire periphery of the door 2 and is provided approximately at right angles to the flange B. A door rear plate 8 is in plane contact with the flange 6, and is connected to a door front plate 10 via a finder mounting plate 9. The door front plate 10 forms the exterior of the door 2. 11 is a finder made of a wire mesh or a perforated metal plate. On both sides of the finder 11 are finder covers 12 made of a transparent dielectric material.
There are 13. Reference numeral 14 denotes a packing made of an elastic material that surrounds the entire circumference of the finder cover 12. Numeral 15 is a screw for fixing the finder 11 and the door rear plate 8 to the finder mounting plate 9. The space surrounded by the door rear plate 8 and the door front plate 10 forms radio mazes G and H, and an entrance 16 of this radio maze faces the satush 6. As shown in FIG. 4 when viewed from the direction of the EF arrow in FIG. 6, 17 is a trapezoidal metal piece whose base is wider than its tip and arranged in one period. The periodic metal pieces 17 are integrally formed by bending a band-shaped metal plate. The metal piece 17 extends from the periphery of the door front plate 10 on one side of the entrance 16 toward the inside of the radio maze. One surface of the metal piece 17 is substantially parallel to the front surface of the door front plate 10 facing this surface, and the other surface is substantially parallel to the door rear plate 8 facing this surface, and the metal piece 1
The tip of 7 is bent toward the front of the door front plate 10.

Therefore.

The propagation path of the radio wave that has entered the inside of the radio maze is separated by the metal piece 17 into a ■-shaped path and a U-shaped path, as shown by the arrows. ■The path length between the arrows of the shaped path and the U-shaped path can be set to about 7 wavelengths, respectively, or the lengths of both can be changed from each other to improve the radio wave sealing effect over a wide range of frequencies. It looks like this. Furthermore, the trapezoidal metal piece 17 reduces the leakage of radio waves passing through the gap between the door rear plate 8 and the flange 6 to the outside through the entrance 16, and prevents the radio waves from leaking to the outside from the ■-shaped route or the U-shaped route. Since it plays the role of a kind of matching element that efficiently guides the radio waves into the maze of radio waves, it improves the stain wave sealing effect compared to a simple choke structure. The distance between the sash 6 and the peripheral edge of the door rear plate 8 is approximately equal to the distance between the sash 3 and the metal piece 17 at the root 1.

The effects of this embodiment configured as described above are as follows.

(1) A sash 6 is provided almost at right angles to the flange 6 that surrounds the entire opening of the heating chamber 5, and the door rear plate 8 and the flange 6 are connected to each other.
After bringing them into plane contact, the entrance 16 of the radio maze surrounded by the door rear plate 8 and the door front plate 10 is made to face the sash 6.

Since the overlapping area of the door 2 and the flange 6 is reduced, the external dimensions of the door 2 are reduced. Therefore, a high frequency heating device with a good space factor can be provided.

(2) The overlapping area of the door 2 and the flange 6 is small, that is, the width of the flange B extending from the opening of the heating chamber 5 to the outside is small.

Since the flange B has strong mechanical strength and is not easily deformed, the gap between the contact surface between the door rear plate 8 and the flange 6 can be kept small for a long period of time.

Radio wave leakage can also be kept to a minimum.

(3) A plurality of metal pieces 17 are periodically arranged inward from the entrance 16 of the radio maze, and these metal pieces 17 reduce the amount of radio waves that pass through the entrance 16 and leak out to the outside. Since the radio waves are guided efficiently, the radio wave sealing effect of the radio maze can be made better than that of a simple choke structure.

As described above, according to the present invention, the radio wave sealing effect, which is the basic function of the door, is improved better than the conventional choke structure,
In addition, by reducing the overlapping area between the door and the flange around the opening of the heating chamber, it is possible to reduce the outer dimensions of the door and provide a high-frequency heating device with a good space factor.

The effect of implementation (there is something called expansion).

Note that the radio mazes G and H, the routes and shapes of the metal pieces 17 are not limited to those in the embodiment.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the main parts of a conventional high-frequency heating device. FIG. 2 is a front view showing one embodiment of the high-frequency heating device of the present invention, FIG. 3 is a cross-sectional view of the vicinity of the peripheral edge of the door 2 viewed from the direction of arrow AB in FIG. 2, and FIG. FIG. 4 is a front view of the metal piece 17 seen from the direction of arrow EF in FIG. 3; 2. Door, 3. Satsushi, 5. Heating room. 6°°fludge, 8...Door rear plate, 10...Door front plate. 16...Entrance to the radio maze, 17...Metal piece. G, I-1/Radio maze. Applicant: Hitachi Thermal Appliances Co., Ltd.

Claims (1)

[Claims] A door rear plate (8) that is in planar contact with a flange (6) provided around the opening of the heating chamber (5) and a door front plate (10
) and a quadruple radio maze (G), (H) and its entrance (16) are provided on the entire circumference of the door (2). It is provided at right angles to the flange (6), with the inlet (16) facing it. It is also characterized by a plurality of metal pieces (17) extending from the periphery of the door front plate (10) looking into the entrance (16) toward the inside of the radio mazes (G) and (H), and arranging them periodically. High frequency heating equipment.