JPS6115571Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a magnetron.

A conventional magnetron has a structure as shown in FIG. Pole pieces 3 and 4 are arranged facing each other at both ends of the working space surrounded by the tips of the cathode 1 and the vane 2, and magnets 5 and 6, yokes 7 and 8, and anode cylinder 8 create the required magnetic flux in the working space. A magnetic circuit is configured to supply

As shown in FIG. 2, every other vane 2 is short-circuited by connecting protrusions 9a, 10a of strap rings 9, 10. This joint protrusion 9a,
10a is formed by press working from a metal plate material corresponding to a predetermined height in the axial direction of the strap during strap ring molding.

Because strap rings are formed by pressing out relatively thick plate materials, the work hardening of the strap rings after forming is significant, and if they are not sufficiently annealed, they become hardened and brittle, so they cannot actually be used with magnetrons. When installed and used, cracks may occur due to repeated expansion and contraction associated with cooling and heating cycles, and the magnetron may eventually break, resulting in failure of oscillation of the magnetron. In addition, in magnetrons with an output of 600 to 800 W or less, copper, which is the same material as the anode, is used, and it can be easily annealed and mechanical stress can be reduced due to the matching of the expansion coefficient with the anode. However, when the output is higher than that, the heat resistance of the strap ring becomes a problem, and at the same time, it is necessary to eliminate causes such as changes in the output frequency due to thermal deformation and intercrystalline cracks due to an increase in crystals in the strap material. ,
Monel etc. are used. In this case, with the conventional strap-ring forming method, pressing is extremely difficult due to the large thickness of the plate, hardening brittle cracks are likely to occur after processing, and expansion occurs due to the material being different from that of the anode (copper material). Due to the different expansion coefficients, hardened brittle cracks occur due to repeated deformation during repeated operation of the magnetron.

To solve this problem, it is necessary to strengthen the strap ring, which is the most important component for magnetron oscillation and also determines the frequency, but is the most vulnerable to repeated thermal deformation. .

This strengthening measure requires either using a completely strong material for the strap ring, or using a material and shape that can flexibly respond to significant deformation without causing breakage. The former is due to the nature of the strap ring, which cannot be made larger due to other electrical property restrictions, and the fact that there is no such material available, and if the strap is made of an absolutely strong material, the anode vane made of copper This has the disadvantage of causing deformation and loss of frequency stability. Therefore, the present invention was devised for the latter.

The present invention was devised in view of the above circumstances, and an object of the present invention is to provide a magnetron in which the material and shape of the strap are devised to eliminate the drawbacks of the conventional magnetron.

The present invention will be explained below based on the illustrated embodiments.
FIG. 3 shows the strap ring according to the present invention.
The outer strap ring 11 and the inner strap ring 12 are formed into a cylindrical shape, and the outer strap ring 11 has a projecting portion 11a projecting outward as shown in a in a part along the cylindrical axis. The inner strap ring 12 is provided with a projecting portion 12a projecting inward as shown in b. These strap rings 11, 12 are formed by pressing thin plates of iron or Monel material.

Then, as shown in FIG.
They are joined via 1a and 12a. By joining the strap rings 11 and 12 to the vane 2 in this way, a structure that is strong against repeated mechanical deformation can be formed without applying stress to the vane by utilizing the elasticity of the thin plate, and at the same time, it is possible to form a structure that is strong against repeated mechanical deformation. This prevents extremely large work-hardening brittleness that occurs during press punching of plate materials, prevents cracking of strap rings, and provides a magnetron with a long service life.

As is clear from the above explanation, the magnetron of the present invention saves on materials, extends the life of the magnetron, and facilitates press processing because the mold material can be made soft. Because it is molded, it has good precision and is easy to assemble.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a conventional magnetron.
Fig. 2 shows a conventional anode, a is a longitudinal sectional view, b is a transverse sectional view, Figs. FIG. 2 is a perspective view of a main part showing a state in which a strap ring is joined to a vane. 2... Vane, 8... Anode cylinder, 11, 12...
... Strap ring, 11a, 12a... Overhanging portion.

Claims (1)

[Scope of utility model registration request] In a magnetron having an anode structure consisting of a plurality of vanes extending toward the center from the inner wall of an anode cylinder and a strap ring that short-circuits every other vane, the strap ring is made of a thin metal material formed into a cylindrical shape. What is claimed is: 1. A magnetron comprising: a cylindrical magnetron having an overhanging portion connected to the vane in a part along the axial direction of the cylinder, and being fixed to a groove of the vane via the overhanging portion.