JPH0443958Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention includes a rectangular metal box that houses the cathode terminal lead-out portion of a magnetron and a filter circuit element connected to the portion, and a box that covers the opening of the box. This invention relates to a magnetron filter case consisting of a square metal lid.

2. Description of the Related Art Generally, a cathode terminal lead-out portion of a magnetron and a filter circuit element connected to the portion are housed in a filter case, and the filter case includes a rectangular metal box and an opening in the box. It consists of a square metal lid body that covers the

In a magnetron device equipped with such a filter case, electromagnetic waves leaked through the cathode terminal lead-out conductor of the magnetron can be prevented from leaking out of the device by the shielding effect of the filter case and the filter circuit.

By the way, when trying to obtain a satisfactory shielding effect by the filter case, a problem arises when a gap occurs at the fitting portion between the box and the lid, especially a gap whose length exceeds a predetermined value. Therefore, a bent part having a U-shaped cross section is formed by drawing on the outer peripheral edge of the lid body, and the opening edge of the box body is caulked and clamped by this U-shaped bent part. .

Problems to be Solved by the Invention However, when attempting to form a bent portion with a U-shaped cross section by drawing the outer periphery of the lid, wrinkles occur, especially at the four corners. When such a lid body is combined with a box body and caulking is performed at the fitting portion of both, the wrinkles protrude as surplus material from the sides of the lid body, resulting in a smooth caulking surface with no gaps. things become difficult. It is also dangerous to handle.

Therefore, the object of the present invention is to create a filter that does not produce wrinkles, protrusions, or gaps as described above, while forming a bent portion with a U-shaped cross section by drawing the outer periphery of the lid. The purpose is to provide a case.

Means for Solving the Problems According to the present invention, the rectangular metal lid that covers the opening of the box is formed into a deep dish shape by drawing, and the edge of the opening of the box is caulked. The outer periphery has a bent portion with a U-shaped cross section that is held between the two.
The entire peripheral edge including this outer peripheral edge is formed into an S-shaped cross section. The bent portion has notches only at the four corners of its outer wall, and the inner wall of the bent portion is in contact with the opening edge over almost the entire outer surface thereof.

Function Excess material generated during the drawing process of the lid body is absorbed by the notches provided at the four corners of the outer wall of the bent part.
This eliminates wrinkles and makes it easier to insert the opening edge of the box into the bent portion. In addition to providing such a notch, the expansion and contraction effect of the peripheral edge of the lid body having an S-shaped cross section makes it possible to swage the outer peripheral edge of the lid body easily and easily, without any gaps. An extremely smooth caulked surface can be obtained. Furthermore, since almost the entire outer surface of the inner wall of the bent portion is in contact with the opening edge of the box, leakage of electromagnetic waves can be completely prevented despite the presence of the notch.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. magnetically couple the magnetic poles,
The other magnetic pole is magnetically coupled to the other magnetic pole part (not shown) of the magnetron 1 through a frame-shaped yoke 4. A metal rectangular box body 5 attached to the outer end surface of the frame-shaped yoke 4 has a stem portion 6 serving as a cathode terminal lead-out portion of the magnetron 1 and a chiyoke coil 8 having one end connected to a terminal 7 of the stem portion 6. is accommodated. Further, a feedthrough capacitor 9 is attached to the side wall of the box body 5 and forms an LC filter circuit together with a chiyoke coil 8, and the other end of the chiyoke coil 8 is connected to the through conductor of the capacitor 9.

On the other hand, the metal rectangular lid 10 that covers the opening of the box 5 is shaped like a deep dish as shown in the figure, and has a bent portion 11 with a U-shaped cross section formed by drawing on its outer periphery. are doing. The peripheral edge portion including the bent portion 11 is formed to have an S-shaped cross section as a whole, and after the opening edge 5a of the box body 5 is inserted through the bent portion 11, it is caulked.

As shown in FIG. 3, notches 12 are formed in the four corners of the outer wall of the bent portion 11, and after the opening edge 5a of the box body 5 is inserted into the bent portion 11 as shown in FIG. The bent portion 11 is caulked.
As a result, the opening edge 5a is held between the bent portions 11, and the peripheral edge of the lid 10 has an S-shaped cross section and is stretchable. Therefore, when caulking the outer periphery, the lid 1
Even if a strong tensile force is applied to the center of the 0, this can be absorbed. The notches 12 are located only in areas facing the outer peripheral surface of the four corners of the opening edge 5a. That is, the notches 12 are present only at the four corners of the outer wall of the bent portion 11, and almost the entire outer surface of the inner wall of the bent portion 11 is in contact with the opening edge 5a. Therefore, electromagnetic waves will not leak through the notch 12. Note that 13 indicates dents caused by caulking.

Effects of the invention As described above, according to the invention, not only can a bent part with a U-shaped cross section be formed by drawing without creating wrinkles on the outer peripheral edge of the lid, but also the opening edge of the box can be formed at this bent part. This makes it easier to insert the material, and the caulked surface can be made smooth, eliminating the need for protrusions or gaps.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention. Figure 1 is a perspective view of the main part, Figure 2 is a side sectional view of the main part, and Figure 3 is a caulking diagram of the main part. It is a perspective view before processing. 1... Magnetron, 5... Box body, 10... Lid body, 11... Bent part, 12... Notch.

Claims (1)

[Scope of utility model registration request] It includes a square metal box that houses the cathode terminal lead-out part of the magnetron and a filter circuit element connected to the part, and a square metal lid that covers the opening of the box, and the lid is drawn. The outer periphery has a bent part with a U-shaped cross section that clamps the opening edge of the box by caulking, and the periphery including this outer periphery has a cross section S as a whole.
For a magnetron, the bent part has notches only at the four corners of its outer wall, and the inner wall of the bent part is in contact with the opening edge over almost the entire outer surface of the bent part. filter case.