JPS6211474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radio wave seal structure for a door used in a high frequency heating device, and particularly provides a structure in which the radio wave seal performance is not affected by the attachment of a handle or the like provided on the outside of the door. It is something to do.

Traditionally, a slit plate has been installed inside the door to improve the radio wave sealing performance of the door, but since this slit plate also forms part of the wall that forms part of the yoke, its mounting position is extremely important. I'm getting older. However, when it comes to the outside of the door, it may be necessary to attach a handle or the like to the front part of the door, which corresponds to the back of the slit plate, and the screws or the like come into contact with the slit plate for this purpose. However, the position of the slit plate has an optimum point in terms of radio wave sealing performance, and if it is moved by even 1 to 2 mm from this point, the radio wave sealing performance will deteriorate significantly. Therefore, the method of attaching the handle and slit plate in such cases is extremely difficult, and in the end, we had to find a compromise that sacrificed the radio wave sealing performance to some extent.

Therefore, in the present invention, the mounting position of the slit plate is limited to the vicinity of the current minimum point of the chain yoke, the slit plate is divided at necessary points so as not to interfere with screws, etc., and the interval between the divided slit plates is adjusted to the distance between the slit plates. By making the size almost the same as the width, it is improved so that handles, etc. can be attached freely without any adverse effect on the radio wave sealing performance.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the entire product related to the present invention. There is a heating chamber 2 inside the main body 1, and a magnetron 3, which is a high frequency oscillator, is located in the upper center of the heating chamber.
is provided. An opening at the front of the heating chamber can be opened and closed by a door 4. FIG. 2 is a diagram showing the inside of the door 4.

Reference numeral 5 denotes a chiyoke groove having a depth of about 1/4 of the frequency used, which blocks radio waves in the X direction. 9 is a short circuit wall of the chi yoke, and at this point the electric field becomes zero at the maximum current. Reference numeral 6 denotes a slit plate that forms a part of the wall of the yoke and also serves to prevent the propagation of radio waves in the Z direction. Since the slit plate is provided near the opening of the cheese yoke, at this point the electric field is at its maximum with almost the minimum current. Since the door body 7 is provided with a stepped part at the center of the upper part for attaching the handle 8, a step is created on the mounting surface of the slit plate, and therefore the slit plate is divided near the boundary of the stepped part. There is.

The slits provided on the slit plate have their depth, width,
Changing the pitch changes the frequency characteristics, so slit plates of the same width and depth must be provided at equal intervals, and it is not possible to divide the slit plate provided on one side of the door into multiple pieces. Although no attempt has been made, it is possible to place a slit plate near the point where the electric field of the choke is maximum and the current is minimum, as described above.
Furthermore, by attaching the divided slit plates so that the distance D between them is approximately equal to the width P of the slits, the frequency characteristics of the slit plates are not disturbed.
We were able to create a product with almost the same radio wave seal performance. At the point where the slit plate is divided, the depth of the slit is deeper than other parts, and even though the bottom becomes the mounting surface of the slit plate, the reason why excellent radio wave sealing performance can be maintained is as mentioned above. This can be explained by the fact that the slit plate is provided near the point where the electric field is maximum and the current is minimum, so even if the slit plate is divided, the electric field is not disturbed.

As explained above, according to the present invention, when attaching a handle, etc., it can be attached at any position without disturbing the yoke dimensions at all and without affecting the radio wave sealing performance, and at the same time, the slit plate can be divided into multiple pieces. Even when making a large door, multiple slit plates for small doors can be used in common, leading to many advantages such as saving on mold costs and reducing the number of types of parts.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the entire high-frequency heating device showing one embodiment of the present invention, FIG. 2 is a perspective view of the main parts thereof, and FIG. 3 is a detailed view of the same slit plate. 1... Main body, 2... Heating chamber, 3... High frequency oscillator, 4... Door, 6... Slit plate, 5... Cheese groove.

Claims (1)

[Claims] 1 Consists of a heating chamber, a high-frequency oscillator, a door that can freely open and close the opening of the heating chamber, and a slit plate provided near the current minimum point of the cheese yoke in the door, This high frequency heating device is characterized in that a slit plate provided on at least one side is divided into a plurality of pieces, and the interval between the slit plate and another divided slit plate is set to be approximately the same as the width of the slit.